died thread: >>1861536>I'm new to electronics. Where to get started?It is an art/science of applying principles to requirements.Find problem, learn principles, design and verify solution, build, test, post results, repeat.>Project ideas:http://adafruit.comhttp://instructables.com/tag/type-id/category-technology/http://makezine.com/category/electronics/Don't ask, roll:https://github.com/Rocheez/4chan-electronics-challenges/blob/master/list-of-challenges.png.png (embed) (embed) (embed) (embed) (embed)>Principles (by increasing skill level):Mims III, Getting Started in ElectronicsGeier, How to Diagnose & Fix Everything ElectronicKybett & Boysen, All New Electronics Self-Teaching GuideScherz & Monk, Practical Electronics for InventorsHorowitz and Hill, The Art of Electronics>Design/verification tools:LTSpiceMicroCapfalstad.com/circuit/circuitjs.htmlNI MultisimCircuitLabiCircuit for MacsKiCAD (PCB layout software, v5+ recommended)>Components/equipment:Mouser, Digi-Key, Arrow, Newark, LCSC (global)RS Components (Europe)eBay/AliExpress sellers, for component assortments/sample kits (caveat emptor)Local independent electronics distributorsladyada.net/library/procure/hobbyist.html>Related YouTube channels:mjlortonw2aewjkgamm041eevblogEcProjectsgreatscottlabPhotonvidssdgelectronicsBigClive>Li+/LiPo batteriesRead this first: http://www.elteconline.com/download/pdf/SAFT-RIC-LI-ION-Safety-Recommendations.pdf>I have junk, what do?Recycle the blue smoke
i wish i had a shirt with "shutterstock" written on it
>>1868384I wish i had safety glasses to protect my hand from being burned by heatguns
Figured out the kicad thing.Turns out there is a second ground plane on the bottom which connects all the top ground planes together so kicad was correctly showing no errors and if i had chinks make the board it would work fine.The problem is only if i make the board myself it wont work because my holes are of course not plated through, which means in my case i need to connect the red ground planes to the green plane with the extra vias i now addedAlternatively this issue could also be solved by soldering the THT components on both top and bottom but i can't be assed to do that.
>>1868399Don't call me Chink, Ricist!
>>1868399Weren't you ordering the PCB from a manufacturer? As a home-etcher I also run into the "no plated THTs" issue, makes me want to go SMT instead.As far as settings go, you can probably configure it so there are only solder pads on one side of the PCB, or just use a single-sided board if that's an option. Though single-sided boards are really limiting, not something I'd consider for this kind of project.Soldering the parts on both sides is an option for components like DIPs and transistors and resistors, but for pin headers and flush pots/trimpots and the like it isn't feasible.Could try the conductive ink +electroplating method (identical to electroforming but cheaper), iirc you can get fine graphite powder pretty cheap in the form of lock lubricant. Not sure what sort of adhesive to use though. Copper electroplating will also cause the PCB thickness to increase. Also there's a bunch of electroplating additives to change the geometric biases of the plating (e.g. towards/away from sharp edges) which I'm entirely unequipped to talk about. I tried making my own conductive glue once, using house paint mixed with charcoal that I made in a tin can in my backyard over a little propane cooker. The charcoal was too coarse even after I crushed it with a rock on the pavement, and my snot was black for a few days afterwards.There's also electroless methods like palladium and quite possibly silver too. Never seen anyone use a silver mirror for plating THTs, but it should be a lot cheaper than getting that palladium salt.There's always THT rivets, but they don't sit too flush and require a tool. If you're doing etching anyhow I'd lean towards a chemical plating method, but if you're routing your traces you may be able to make slight recesses for the rivets to better fit into.
What do I connect this to, to then attach 2,5mm cables?
>>1868441even if you manage to pull the male equivalent off of a PCB, then what? you'll have to solder wires to the male pins. so might as well cut off the connector and solder directly to the wires. but you dont have a soldering iron! then you can get spade crimps. but you dont had a crimper! so, either spend some money or give it to someone who has the tools and knowledge.
>>1868444Okay, so just crimp these then I can connect. Thanks.
Brainlet question.I have a large infrared heater that was running on 120V.It's wired like pic related (8 parallel branches with 3 series tubes in each).I want to run it off 220V so I was going to change it to 4 parallel branches of 6 series tubes.I was trying to work out the current rating the cable would have to be for making jumpers and I must be doing something wrong.If they're in series of 3 at 110V then voltage drop across each would be 36V odd so a 500W tube would pull about 13.5A.Therefore each parallel branch would be pulling 13.5A giving a total current of 8 x 13.5A = 108A?The input breaker for the unit when it was running at 110V was only 20A so what am I doing wrong?
>>1868518Oh wait, it's the series resistance isn't it?
Everybody knows the old welder-from-a-microwave trick, but what about DIYing a welder with batteries for improved portability? Would 6s (24v) be enough to strike an arc or does it need more volts?
>>1868539It's called an inverter, and good luck. That kind of power electronic shit is on the border where it's better to buy than to /diy/. You could try a spot welder tho, with huge fuck capacitors.>>1868518Sorry I am confused, is it 500W? If yes then>p=Vrms*Irms>500/110=4A and change
>>1868542And if you actually measured 20A at the breaker then:>P=20*110>2.2kWIf the rated power is 2.2kW then for the same power at twice the voltage you would need 4 times more resistance.If you use Ohms law and P=V*I and a bit of algebra you'll reach the conclusion thatP=V^2/R.
>>1868518>a 500W tubeIs the tube 500w or the entire heater 500w? If each tube is 500w that would make the whole thing 12000w, which no 120v circuit I've seen is even remotely capable of handling. Just take the total power of the entire heater and divide by 220 to get the amps you need (assuming it's a resistive load which heaters usually are).>>1868399If you don't have plated through holes how can you expect to have plated vias? I suppose you could drill a hole and stick a wire through.
>>1868518you doubled the voltage and also doubled the resistance, so the current is the same as before.>>1868539>Would 6s (24v) be enough to strike an arc or does it need more volts?the reason you can weld with a modified MOT is coz it can put out 500 to 1000 amps at 1-2V. your shitty batteries aint even close.
>>1868547>have plated vias?they aren't plated, i connect them manually by sticking a wire through and soldering on both endsi also have a special pcb riveting tool coming in the mail so hopefully that will replace the tedious soldering
>>1868547Each tube is 500WSo now I'm thinking if it was one tube getting 110V it would draw 500/110 which is 4.5A so resistance of a tube is =110/4.5 = ~24.5 ohmsSo if 3 are in series it'll be about 73.5 ohms.Then 110/73.5 = 1.5A through the series.So the total current would be 8 parallel branches with 1.5A each = 12A
>>1868558If each tube is rated at 500W then you are not running it a full power if you measured 20A at the input. Something is wrong here, either you are not being clear or I'm missing something. Did you actually measure 20A?
>>1868548>the reason you can weld with a modified MOT is coz it can put out 500 to 1000 amps at 1-2VSurely it doesn't need to be that much. The welders I've looked at advertise 100-200A at full power, which is totally doable with batteries. I assume that is an average current, I don't know if it needs to spike higher than that to start or something.
watching thew mill drill precisely centered tht holes is downright orgasmic
>>1868570>The welders I've looked at advertise 100-200A at full power,those are stick welders. MOT welders dont use anything other than current to weld. if you wanna do stick, two car batteries in series work fine.
>>1867348>using an entire inverter ICSpeaking of inverter ICs, I think this is pretty clever use for a 74HC14.https://www.radiolocman.com/shem/schematics.html?di=150510
>>1868582>those are stick weldersYes, that is what I am interested in. I see now that there are plans for making both spot and stick welders from microwaves, so maybe that wasn't obvious.>if you wanna do stick, two car batteries in series work fineThat's helpful, makes me think I'm on the right track.
>>1868566No I didn't run it. I initially assumed that since it's a 500w tube and 3 in series would have 36 volts across them that they'd pull 13 odd amps but I never took the resistance into account which would reduce the current
>>1868603500 watts * 24 tubes = 12000 watts = 41000 BTUs = enough to heat a typical 900sqft house. Alternately 12000 watts / 120 volts = 100 amps = literally all the power that typical 900sqft house is capable of receiving from the power company (yes, I know many houses have 200A hookups but whatever.)I see three possibilities. 1. You're interpreting the specs wrong. Can you post a pic or datasheet or something?2. As other anon suggested, the tubes are rated for 500w but are run at much lower power for better longevity.3. You've gotten your hands on an ABSOLUTE UNIT of a heater and will probably burn your house down.
If I have an E-scooter with a lead-acid battery (sorta like pic related) and I swap it out for an 18650 pack, will I have to replace the charger/controller? Is it worth it for a 24volt / 100watt motor?
>>1868603>I never took the resistance into account which would reduce the currentNo it's not that. You need 2 (Only two!) variables to solve these things, Voltage, Power and current. If you give all three the results must check out because then there is nothing to solve.>>1868518>The input breaker for the unit when it was running at 110V was only 20A so what am I doing wrong?This says the current is less than 20A for the whole thing wired the way you said, so each one of those legs can get 2.5A without tripping the breaker (20/8). With 36V across each element that gives a power of 91W (2.5*36) per tube not 500W. With 91W the resistance (While hot!) would be about 14. something Ohms (R=p/i^2 => 91W/(2,5*2,5)=14). The total resistance for the 110V would be then 5.25 Ohms (14 ohms* 3/8 tubes). The math checks out now because 110/2,5 = 20 somethings amps = your breaker rating.Now your idea will work, because if you make 4 legs of 6 the total resistance will be 21 Ohms (6*14 /4). Because as I said here :>>1868546 >for the same power at twice the voltage you would need 4 times more resistance.>Tl;drYour idea is correct but I have no idea where you got 500W and a billion amps. If you just wire 4 legs of 6 it'll work.>>1868661>https://enerdrive.com.au/2017/11/29/can-charge-lithium-battery-lead-acid-charger/Most likely not gonna work.
>>1868664It'll work regardless of the actual resistance value btw, as long as they are all the same and assuming it ran with the 20A breaker ok. The new current rating will be half of the old one.
>>1868627what the fuck is he sitting on
>>1868673mutt wheelchair with vinyl shitting cushion.
>>1868664>4 times more resistanceisn't 4 times more = 5 times as much?
>>18686752 is 1, and 1 is none.
>>1868675Uh not, exactly 4. I rounded some stuff because I suck at doing math on my head. >P=V^2/R
Are vintage stereo amps (70s and 80s) worth it, or are they just a meme? Especially when you take into account the reliability and tolerances of the parts manufactured in their day compared to now.My Grandfather dug up an old Soviet stereo amp and is currently "restoring" it - tracking down old parts, components, etc. to make it fully functional again. The primary issue is that the internal parts (transistors, capacitors, etc.) are blown and are hard to track down, due to them being old/no longer manufactured, or the parts are either not matching or reproductions and no longer the same. A lot of this crosses over into Audiophile territory - trying to hunt down the exact transistors that were matching from the factory, as the reproduction parts produce different results that aren't ideal. And a lot of this got me interested in getting my own vintage stereo amp, and whether they're truly better than today's digital amps or just a hipster audiophile meme
>>1868677ok, schools are closed forever
>>1868685It's audiophile crap
>>1868687Two birds, one stone. See?
Also, continuing from the amp - are there any good, reputable sites for getting rarer components for vintage stuff? I'm skeptical of ebay in case of false advertising or the parts are not as described. I'm hunting down soviet transistors (part no. KT808A) that are matched from the factory.
>>1868690Use modern equivalents to get it running again and take your time to source the originals. Ebay is your best bet in this case.
>>1868697Time isn't so much the issue, the project's been going on for a year with the intent of doing it right rather than doing it fast. The issue with using modern stuff is that it's not quite the same - the whole charm and sound quality from vintage stuff (amps, synths, etc) is that the parts that were made in that time had different tolerances, manufacturing methods, and materials; because the quality wasn't as consistent, it created a variance in each product down to the part that gives it the coveted vintage sound and feel. Modern components make it pointless, especially if you just discard them afterwards once you have the desired vintage ones.
>>1868698That's all true, but are you going to use the amp to listen to a vinyl record collection or modern digital sources?
>>1868706It's my grandfather that will be using it - I'm just along for the ride because I like electronics and vintage stuff.He'd be doing a mix - he's pretty tech savvy and uses computers + listens to music digitally, but also has some bonafide vinyls and record players he still uses which he bought from its respective era.
>>1868711In that case you could probably find acceptable components in Kenwood or Pioneer amps from the same era. One thing you'd probably have trouble replacing 1:1 is old capacitors, for obvious reasons.
>>1868583oh neat>>1868603So you know, you can't just measure the resistance of an incandescent lamp and treat it as a constant, those lamps have a much lower cold resistance than their hot resistance.Where'd you get the "500W" rating from anyhow?
>>1868664>>1868728Sorry, the tubes themselves say 500w on them. Pic related is from the manual from the machine I took the heater out of. It was being used to head large pcbs from the bottom in a hot air rework station
>>1868745Then I'd say that the tubes themselves are meant to run on 120VAC and are being undervolted. Who knows how much power each lamp is drawing in the current configuration, but it's probably 30-80W each.
Does anyone have any infographic or any recommendation for good budget multimeters and soldering stations?
anyone got experience with precision water heaters?I'm thinking of building my own sous vide cooker from a raspi and some sensors, so it only needs to be able to get maybe 5 gallons of water up to ~165F topswould I be better off buying a prebuilt one, or should I try to build it myself?seems pretty simple, just wrap some bare metal wires around an insulator and waterproof it, but that also seems like a good way to die
>>1868748Yeah, that's what I'm trying to figure out. If I'm reconfiguring it, I'm gonna have to make wire jumpers so I wanted to work out the max current I'd be pulling through the wire to make sure I use a large enough cable
>>1868754Buy a proper heating element and controller unless you want to trial & error your way through debugging/failsafe features.
>>1868750I got this station from ebay about 3 years ago and never had any issue with it. Mind you I've only used it for through hole and some larger smt components but I've not even changed the tip since I got it and I've made thousands of joints with it. Depends what functionality you want in the multimeter but I've a cheap as fuck uni-T ut30c that seems accurate enough in voltage and resistance anyway.I did melt the original cables off it by pulling 8 amps through it though
>>1868745That makes a lot more sense. Probably using oversized bulbs at lower voltage was cheaper than purpose-built infrared bulbs.>>1868755You're gonna have to measure, or else guestimate since the bulbs are probably not specced for the reduced voltage. Since you are doubling the voltage but putting twice as many bulbs in series, it should be safe to assume they will get the same voltage, current and power per-bulb. Since the entire setup evidently used to function on <=20A at 120v, it should function at <=10A at 240v. Divide that by the number of strands (20/8=10/4=2.5) to get the current per-strand. That should give you an upper bound, the actual current could be way less. Make sure your insulation and clearances can handle the higher voltage.
>>1868759Yeah, that's what I figuredare there any out there that you'd recommend?
>>1868775I don't own any of this, but this stuff should work okay.Controller: https://www.amazon.com/Inkbird-Temperature-Controller-Controlling-Fermentation/dp/B07PVBG8K1Heater: https://www.amazon.com/Precision-Premier-Line-742G-Submersible/dp/B000BDB4UG
>>1868781that's pretty much exactly what I wanted to buildkinda takes the fun out of it, but I guess it ends up being less expensive than most of the sous vide cookers on the market, and I still have more control than they give youthanks
>>1868755Hasn't this been solved already? If you double the voltage and quadruple the load resistance you get half the current and the total power remains the same.
I bought a Direct Logic 06 PLC which I've used in classes before and I found relatively cheap. Wanna experiment with it and potentially use it for some projects. My problem is the software...The DirectSOFT6 license is $417 from automation direct. This is like 4x more than I paid for the PLC itself. Anyone know if/where I can find the full software for free? Tried the usual suspects like TBP. Absolutely nothing. I'll pay it if I absolutely have to but I wanna scour the internet first and be absolutely sure I can't find it elsewhere.
>>1868754Immersion heaters for mains voltage are like $5 each, no reason to attempt to make your own. Then a PID controller will run you maybe $25-50, and those things are designed to run off mains and have all the requisite power supplies, and don’t need an external mcu or computer. Not sure how easy it is to control them externally for programmed temperature profiles, but it should be possible. They have some buttons and an LCD on the front for simple control. I’d also include a little aquarium pump so the water can move about and stop a temperature gradient between the element and the temp sensor. Those PID controllers also have integrated thermocouple reading hardware, probably common thermistors too. Will probably need to buy the temp sensor itself, but that’s cheap.
Why aren't transconductance amplifiers taught in school?My advanced electronics classes covered all kinds of op-amp configurations, but OTAs were never mentioned.Granted that OTA's aren't quite as versatile as op-amps, but when you need them they're super handy.
>>1868862because what you're supposed to learn is how to figure it out for yourself?
>>1868863How are you supposed to figure them out for yourself if you're never even told about their existence?It's like being taught how to program without ever being told about dynamic memory allocation.Yes, you can write your programs with nothing but statically allocated memory, but you can do so much more with dynamic memory allocation.
>>1868868Because that's experience, not basic theory? Is this the first component you've come across outside your degree? Have you bothered to look through digi-key just to see what's out there? How much hand-holding do you need?
>>1868902>Because that's experience, not basic theory?Bitch what? Dynamic memory may be a basic building block of programming, but it's a very complicated topic.I wouldn't trust anyone who taught themselves how to use dynamic memory because there's so many pitfalls in how to use it that cause hard to fix bugs if you don't know what you're doing.>Is this the first component you've come across outside your degree?No, why would you assume that?>Have you bothered to look through digi-key just to see what's out there?Do you learn all your electronics knowledge through datasheets? Because that's a terrible way to learn basic theory.Datasheets are for telling you the specifications for a specific part and maybe giving a few example circuits.>How much hand-holding do you need?Is teaching how op-amps work handholding?Is teaching the 3 basic transistor amplifier topologies (common base/emitter/collector) handholding?Is teaching diodes handholding?Is teaching how transformers work handholding?Is teaching how resistors/inductors/capactors handholding?Should professors just throw Maxwell's equations at their students and tell them to figure the rest out on their own?
>>1868933....retard, this started off complaining about not learning from _professors_. What the fuck are you talking about self-taught for? Desperately needed strawman?
>>1868942Who else is going to teach you about electronics?I can't imagine an employer teaching you about OTAs.That leaves self education.>Desperately needed strawman?Mate, I've seen stronger arguments from strawmen than what you've presented.
Is there a type of annular sensor I can buy for measuring the radial compression of a ring? annular load cell, etc turns up nothing.>>1868580that's sweet but i think your bit is dull
>>1868956Fill it with oil and pipe it to a pressure sensor?IIRC load cells aren’t good at compression, just tension, but usually that’s just a matter of perspective and changes based off how you arrange the geometries of your parts.
>>1868956Try a buttplug.
>>1868948The conversation started out as someone who graduated with an electrical engineering degree. You descended into talking about fucking passives. Please go fuck off with that reductive noise.
>>1868973>Professors teach about voltage amplifiers, current amplifiers, and transimpedance amplifiers>but don't fucking teach about transconductance amplifiers, that's handholdingThis is you.
>>1869010Incorrect, you seem incapable of understanding what I said. I shall spell it out further since you can't get over the minor hurdles.Professors teach a subset of all EE knowledge, and you are expected to generalize, and learn on your own post gradutation. You can also learn from mentors on the job, which I didn't even bother explaining, because i wasn't trying to explain all the sources of information, only that professors aren't responsible for teaching you everything. They cannot, there isn't enough time. They are expected to pass along sufficient knowledge and skill that you can understand industry standard documentation. Apparently you didn't learn this at all.Apparently you think EE is "Everything you learned" + OTAs, not understanding how big the field is, and how little material is covered.
>>1869030Anon, transconductance amplifiers are literally one of the 4 basic kinds of amplifiers which relate voltage and/or currentThis isn't some obscure topic, it's just as fundamental as inductors are to passive components.
>>1868862Non-meme answer: because they're barely used in the real world. Usually it's either textbook op-amp circuits, transistor circuits, or DSP, with some weird shit around RF circuits. Also dedicated voltage-controlled-amplifier ICs and mixers, and digipots, in the case that DSP isn't being used for voltage-controlled amplification/signal mixing. Only in the audio effects world do OTAs get a significant amount of use, and the common circuit blocks used by audio effects are quite far removed from the rest of analog electronics, so to learn any of them, including OTAs, you'd need to take a course specifically focusing on audio circuit design.t. guy wants to implement effects pedals with DSP on an MCU
>>1869048memristors are one of the 4 elementary passive circuit elements, how didn't you learn about those in high school alongside caps, coils, and resistors?
>>1869048Confused still. I'm not saying they *shouldn't* be taught, im saying any given curriculum cannot teach everything, and the point is to absorb enough information that you can understand. Maybe you failed at this.You say they are fundamental, but they are only if you are in that area of the field. I spent way more time studying EM fields and semi-conducting materials, mostly because I wanted to. First job was working with FPGAs, custom ASICS, and PCB design, which I never learned that in school (some did, I didn't take those classes, was more curious about photonics). Never touched amplifiers outside of school, and that was 20 years ago now. You don't seem to grasp how big the field is.
>>1869048OTAs are seldom used and therefore it's not worth teaching about. You'd never see an OTA in pretty much any commercial or industrial piece of equipment. It's literally only used by audio people doing /diy/ synths and stuff like that. It isn't even used in professional audio applications where everything is typically done digitally. In short OTAs are basically obsolete parts. There's no sense covering them in school, if you have a good grasp of electronics you shouldn't need to be taught how they work you can read the datasheet for the LM13700 which explains their operations in more than enough detail and provides internal schematics and whatnot. If you need a teacher to have taught you this you're not a very good engineer.
>>1869059reminds me of that one guy in an eevblog comments section who worked in a crystal factory (i.e. oscillators) and had a whole slew of extremely specific information about how the best crystals are made, and how cheap crystals differ from properly made ones, and how shocking a crystal resets its drift, and all this incredible info. was on a video about dremelling apart a crystal oscillator to see the internals. incredibly specific stuff, but possibly useful for those of us trying to select crystals for a project where quality matters.
>>1869050They were mentioned at least.No effort went into learning them though because we're still trying to learn how to make them.Meanwhile OTAs have been around for ages.We actually did learn about gyrators in detail though.>>1869049>because they're barely used in the real world.While I get what you're saying, I was taught about plenty of things that are rarely used in the real world, like jfets, and lots of the circuits we built in the labs used crusty old ICs which aren't in production anymore.>>1869059>Confused still.You sure do love your ad hominen, I think you've done that in almost every post.>im saying any given curriculum cannot teach everything,No shit>the point is to absorb enough information that you can understandRight, I don't see how that precludes introducing the concept of an OTA alongside all of the op-amp stuff.It doesn't have to be a super in-depth lecture, just mention it and give the students the basics, like half the other shit that we briefly touch on in class.>Maybe you failed at this.More ad hominen, you really can't help yourself>I spent way more time studying EM fields and semi-conducting materialsAnd I spent more time on digital logic and processor design.I still had to take advanced classes on analog electronics, AC power, and loads of other stuff.>First job was working with FPGAs, custom ASICS, and PCB design, which I never learned that in schoolAll of that, except ASICs, is required coursework in my degree program.>Never touched amplifiers outside of school, and that was 20 years ago now.Ok, and I won't touch half the stuff I learned either, but like you said, the point of the classes is to educate you about a wide variety of topics so you are familiar with them.>You don't seem to grasp how big the field is.More ad hominen.I'm not talking about entry level electronics classes, I'm saying that I've taken everything from intro to electronics to the graduate level courses and OTAs were never mentioned.
Shh, nobody tell the autist about current feedback op-amps the only op-amps that have 1GHz+ gain bandwidth products. Nobody tell the autist about current differencing Norton op-amps. Forget op-amps even, nobody tell the autist about Heterojunction bipolar transistors, or MESFETs, or negative resistance oscillators like Gunn diodes.Nobody tell the autist about all the fucking weird exotic components out there that you never learn about in school. He doesn't get it.
>>1869074Not a single thing you've posted forwards your case that OTA's should be taught, at all, and demonstrably it's false as you weren't.Where are you going with this? All you've done is put words in other people's mouths and completely misunderstood the main counter-point: Not everything is taught in every program, and even within a program, people don't learn the same stuff once you hit electives.
>>1869083>current feedback op-ampsThat's just another variant of the transimpedance amplifier, which is taught by almost every professor>Norton op-ampsThat's another kind of transconductance amplifier.>negative resistance oscillators like Gunn diodes.Really not that complicated>all the fucking weird exotic components>Implying that OTAs are exotic
>>1869084>All you've done is put words in other people's mouths He says as he repeatedly puts words into the other anon's mouth.>completely misunderstoodYou don't seem to understand that anon's argument either.
regrets? only one: wish i'd spent MORE time engaging in fruitless arguments on 4-chan.
Well, all the components arrived for me to make my red flashing LED. The original idea was to make a fake alarm light and hide the switch somewhere under the dash. But I got to thinking: why not make a real alarm?Basically I want to wire 6 magnetic reed switches to the six doors. When one of the doors opens, it triggers a 120dB speaker to go off. Do I need to wire the switches in series or parallel? For a kill switch for this reed switch alarm, can I hook it up to the same kill switch for the blinking light? I was thinking maybe having a 7th reed switch connected to one of the door lock levers because they move when I lock the vehicle so it might be easier or better to use that as the main switch for the actual alarm bit. Or maybe both the speaker and the light, I'm not entirely sure. The only problem I see is that say someone does open the door while the alarm is armed, if they shut it, the alarm goes off. Which would kind of defeat the purpose, at least partially. One problem I can think of is trying to arm it while getting out of the vehicle. So that's the main reason I was thinking of using the lock lever as the switch. Would I need another 8-pin Dip to drive the speaker? I ask because I had to buy 10 sockets and 10 boards so I'm trying to come up with some ways to use them. I only have capacitors, about 10 of 10 different sizes, but I can get whatever components I need for this. I guess I could just buy a professionally made alarm kit, but where's the fun in that?
>>1869128Ah shit, I was just thinking, if someone used a Slim Jim or something similar to unlock the vehicle, the alarm would turn off. So that spot for the switch for the speaker is a no-go.
>>1869120Do radio waves turn you into a tranny?
>>1869132o fuk its 5gthere's a bee joke here isn't there
>>1868580no it's not, the bit is new and it goes through the pcb like butter
>>1869135>jokeNo jokes here, only reality.https://www.youtube.com/watch?v=ppj3gqUTt9E
>>1869146no i've seen a bit of glasslinger, entirely uncannyi was just wondering if there's a>5g makes you trans>5g is killing bees>the minecraft bee is transcircle of memes to be had
>>18691535G is making our bees trans, causing a spike in bee suicide rates.
An interesting /ohm/ related thing happened in the town next to mine.So basically a father and his two sons went to check on a submersible water pump they had running in a lake next to their house, and the next day a relative of this family found them all floating in the lake, face down.And i am trying to figure out how the fuck does that happen. The water pump which achieved this multi-kill had a short, but the problem here is, unlike in the movies, if you throw a toaster in a bath tub there isn't an electric storm happening, there will just be a small short between the live and neutral and thats it. The only way to get yourself zapped is to grab a live wire or live casing and touch the water, where the only path between the two is your body. But skin has very high resistance so there will always be an easier path between the live and ground, like through the water on your clothes and such.So dad grabs the live wire, turns into a statue, son grabs dad to help, gets medusad as well, and the third son is dumb enough to complete the daisy chain?So fucking weird. mains aren't even that strong, it's just shitty 230V
>>1869184guy picks up metal pump, electricity goes from the pump in his hands, down into his chest, through his heart, and continues down to earth. son jumps in and grabs his father and leans back holding him against his chest, electricity now goes through his father and into his chest and heart, then down to earth. second son witnesses the death of his father and brother and inhales water.
>>1869184black eels are very dangerous
>>1869184Usually he touches something live, can't let go of it screams for help, the other person tries to pull him out and gets shocked too.
>>1869196>screams for helphaha funny meme friendi see you never touched a live wirehttps://www.youtube.com/watch?v=bkw5mL23iLk&has_verified=1
>>1869197either the shock stuns/kills you, or it just hurts/causes non-critical muscles to spasm. in the latter case, screaming can certainly happen.t. had 2 mains shocks
>>1869198i have seen COUNTLESS videos from chinkland of workers touching live wires and they always turn into statuesblocks of marble cannot scream
>>1869197I have touched wires but fortunally never had the situation where my grip got stuck or shit went through my heart. Usually from the hands to the arm (which was touching something) or between fingers. And you can clearly see the bovine screaming.>t. person you quotedI wasn't saying like:>touches wire>grip gets stuck for 10 minutes>during said 10 minutes dude screams for helpI was saying literaly>touches shit>scream, gets stuck and non-responsive>other dudes pulls him and gets shocked>time passed, 5 secondsAnyhow, seeing your kid T-posing while fixing a pump may be alarming enough without a scream.
>>1869200yeah, because that's the former case, stunning or flat-out dyingbut "i see you never touched a live wire" implying you can't scream in any possible case (even extremely light non-lethal shocks) is flat-out wrongmight as well be saying "lmao, this pleb hasn't suffered a lethal shock before" if that isn't what you were implying>>1869201>seeing your kid T-posing while fixing a pumpthis made me laugh more than it should have
Any projects for a decent usb microphone?
>>1869221yes, walk into thrift store with four $1 bills and walk out with a Band Camp or Rock Band USB mic with a nice long cord. enjoy great quality mic'ing.
>>1869146I blame J. Edgar Hoover.
Electric organ outputs no sound, either amp or headphones.Looks like IC501 a 5V regulator blew and fried the the IC's I marked in red, solder on the underside is dark brown.Also the diodes circled are completely black.My guess is change IC's, diodes and we're probably good to go, right? I've done this many times but I've never seen diodes affected after a voltage regulator blow.
not sure if this is for /ham/ or for this thread.I'm about to buy LoRa modules because I've read that they have great range. now, people use them with 0.5mW, or 0.25. but, I'm curious if I could increase wattage to like 5 watts and get even more range? couldn't find anything about it online. also, I know it's illegal, but I don't really care (just wanna test it so I doubt I'll get in any trouble)
>>1869430>LoRa modulesYou gonna play some BBS door games?LORD and Pimp Wars at a blazing 9600bps?
>>1869404Pic won't upload don't know why.
Hi /ohm/,Had some basic EE classes, but it was all theory apart from hand-winding a coil.Here I am now, trying to make a phone charger (Android) for use while bicycling.The bicycle dynamo says "6V 3W" on it, which seems true when it is connected to the lights, but gets up to 30V when unloaded, why is this? (AC voltage measurement, this is RMS by default right?)Found some schematics, ordered some components, most importantly: a buck converter and a linear voltage regulator, to test both approaches.I assembled like in the schematic, where I kept everything the same except the blue component I tried both these options.The system works and charges my phone when applying 12V DC to the input.On my bike, the phone says it's charging really shortly (1-2 seconds) and then stops charging. Usually, when the phone has stopped charging, the voltage over the 2200 uF cap is above the rated 16V, so I ordered a 30V version, would this be better?Should I take an entirely different approach? Tips?
>>1869461Try 15k resistors between D- and 5V, and D+ and 5V before the USB socket.
I have run out of ideas here. I need to measure the op current from a modified smps, the op is ac at 30khz and current 10amps.Have an ebay dc current/volt meter, the current viewing resistor designed to give 75mV at 50 amp but cant be rectified cause voltage to small.Tried ct into bridge rec. of 4 x 1n4148's with 1k pot but op is not linear.Will a precision rectifier work ie be linear, accuracy should be at least half amp.??Any other ways to measure this?
>>1869470I think this is only relevant for iPhones, as the phone did charge normally when connected to 12V DC. I connected the D+ and D- lines, apparently Androids recognise this as a "charge only" device then.Is this what you meant?
>>1869436no, I'm going to send sensor information
>>1869474>Samsung devices require 1.2V voltage on both D+ and D- data lines, see the schematic. The R1/R2 voltage divider is providing the required voltage on the D+ and D- pins of the USB connector to be recognized as Samsung native charger. That's it. The only issue is that completely discharged Galaxy Tab battery might draw even more than 500 mA from the USB port, when the USB 2.0 specification limiting the maximum current load to 500 mA. USB 3.0 specification makes improvement here and increased the maximum current to 900 mA. The divider resistor values are not critical as far the divider ratio remains the same, i.e. 0.24 or closer.from http://www.obddiag.net/usb-power.html
>>1869430Definitely a question for the hams. IIRC LoRa has a bunch of standards in place to stop individuals from hogging the bandwidth, and transmitting on a higher power would likely interfere with this.>>1869473Precision rectifier with an op-amp and two diodes should work just fine. Turn it into a voltage follower circuit and just measure the DC value. Also lmao at noscope pleb.
>>1868373rolling for challenge
>>1869613This is the trace at pin 15 on the pwm controller my man lmao.Im wondering if a current probe type circuit might work as they have to be very linear.
>>1869968So long as you use a topology that prevents the op-amp from entering saturation you should be fine. I think EEVblog has a video on that kind of ideal rectifier.
How do I do this? I bought an ebike for very cheap because it's a pedal assist type bikeThe motor only turns on when it detects that that you're pedaling, as it detects the movement of the pedal bracket. I figured that if I simply buy a new speed sensor and fool it by attaching it to my wheel instead (which obviously spins around regardless of if i'm pedaling or not) so i could practically turn it into a legitimate ebike.I still don't want to lose the original pedal assist functionality so my question is, how do i go about making a switch that chooses between the bracket sensor and the pedal sensor? the cables used are the ones shown in the pic, i think it's called a 3 pin SM JST (not 100% sure about the wire colors, just took what i got from google to make the pic real fast)
>>1870082if there are 3 wires you can get a 3 pole double throw switch, then hook the two sensors to either side and the output to the common poles. You could probably do it with a dpdt switch with shared ground if you knew what you were doing.Do you have a plan for stopping? If it was previously controlled by pedaling and you rig it to think you are always pedaling it seems to me it will just keep accelerating.
>>1870093Once any brake is pressed, the motor always automatically turns off. There's a built-in killswitch, so to speak.Also I suppose it doesn't have to be a toggle switch, a top-down button would work just as well because then I'd return to normal mode once I let go of the beast mode button.Can you elaborate on the shared ground thing?
>>1870103>Can you elaborate on the shared ground thing?if you had some basic electrical knowledge, and a good idea of what the 3 wires are doing, you could avoid switching all 3 wires, and switch just 2, or even just one. but you dont, so dont take any chances and get a 3-pole double throw switch. should have 9 pins on the bottom.
>>1869461>but gets up to 30V when unloaded, why is this?Motor generators (and generators in general) have some minimum required load to maintain regulationHow it behaves without regulation depends on how output voltage is generated but in most cases voltage goes up and just using higher voltage rating capacitors is not good ideaA solution to this is in most cases -just adding dummy load resistors to maintain some load even if smartphone or LED is disconnected.
hi, can I get electrocuted by voltage or amperage of an external battery (normally used for smartphones)
>>1870155>ust adding dummy load resistors to maintain some loadin series with a zener so it's not wasting power continually, but only when unloaded.
>>1870178nope. that looks like a temporary pushbutton, like a doorbell. you have to keep pushing it to work. what you want is a rocker, like a light switch, that stays in position after you flip it.
>>1870230>that looks like a temporary pushbuttonGo study up on what 3pdt means, and in the meantime stop posting out of your ass.
>>1870240>Go study up on what 3pdt means3 poles, double throwIt does not indicate if switch is latching or momentary or if it is on-off-on or on-on (being pushbutton it should be on-on)
>>1870230It could also be a toggle switch that keeps the last position until pushed again.
>>1870256You are correct. However, that switch is for applications like guitar boxes that you stomp once and it changes state until you stomp again.
>>1870264This. It's a pedal for some guitar shit and is toggleable, so it's either down or up.
>>1869976Its funny, as i increase current the voltage on the current viewing resistor goes up then down then way up as op current is slowly increased where the rectified volts from the CT increases smoothly and almost linear, the response curves up at the high end with 10 actual amps=16 amps on the panel meter I want to use. I need to somehow compensate to pull down the curve at the high end.
>>1870406there shouldn't be any curve on the op-amp at all. post circuit?
I want to learn electronics because it seems a cool hobby. I'm reading your books, but I also want to try and experiment with the things I read: what equipment do I need?
>>1870407Sorry should have been clearer, atm I am testing ideas with image rel. and a current transformer. The pic related outputs the weird up down up voltage as the current is increased, the ct is fed into BRec and trim pot as said above, the ct voltage isnt linear at the upper range (fsd of the panel meter I want to use is 50amps at 75mV)so for a current of 10amps the meter reads 16 amps
>>1870456also to be clearer the CT and ammeter resister are in line with the transformer before the output shockley's I will only need the dc output to indicate op voltage-only drawing power directly from the trafo.
>>1870431Find an application of electronics you find interesting and read everything you can. Find online hobbyists and learn from they're work. become familiar with a range of components. Get a free simulator to get confident with basic equations vir potential dividers etc and the rest will follow as you need.
>>1870474Thanks. I've been reading the first book on the list and it's pretty fun. Analog electronics seems pretty approachable. As for the simulator I was hoping to not use the computer since I already have to use it too much for my taste for literally everything else: I'd like to play directly with components, making easy circuits on those perforated boards and see for myself what happens.
I found this vape on the roadside. Small dent in the battery.What can you do with these?
>>1870514There was still plenty of juice in it. Is this coil fucked? It would explain why a full vape was on the roadside.
>>1870516Can you get a universal charger for all lithium batteries?
>>1870516>It would explain why a full vape was on the roadside.Maybe they hit puberty and decided they didnt want to look like a child anymore, so they chucked it out the window
>>1870506Sims are still useful tools, otherwise you’ll need an oscilloscope to see what your circuit is actually doing. Or a speaker and a good ear, or some sort of sound-card scope. Though it depends on what sort of analog electronics you want to do, get a variety pack of resistors, ceramic caps, and probably electrolytic caps too. Then a handful of transistors, both PNP and NPN (BC547/BC557 are pretty cheap), some 1N4148s, some op-amps and comparators (don’t ask me what to use, my LM324s are distinctly obsolete). Then probably some LEDs, maybe some MOSFETs, stuff like phototransistors or piezo discs. Function generator and scope are pretty damn useful though. I’d get a 2nd hand analog scope and a cheap digital function generator from chinaland.
>>1870521Yes you can. A simple 50c TP4046 board should be sufficient for this. Don’t solder onto the lithium ion cell though.
>>1870525Thank you anon. I'd rather get an oscilloscope than use the PC. I ran a quick search and in my area used oscilloscopes aren't cheaper than new ones from the usual chink sites, so I'd go with the latter: any recommendation? I saw really cheap ones that look like portable mp3 players, but something tells me they're worthless. Still, the bigger models look more powerful than I can handle. Also, why can't a smartphone be used to generate a function through the audio jack? I mean, after all it generates electric signals, doesn't it?
>>1868698>coveted vintage sound and feelMeaning the shittier fidelity?
>>1870536Having warmth isnt "shittier fidelity"
>>1868384They have it
>>1870537It literally is. What do you think warmth is?
>>1870539So you need to introduce artificial decreases in fidelity to get the same soundstage and body as older designs?
>>1870540If I wanted "warmth," yes. But as someone who's not an idiot, I prefer high fidelity
>>1870541Sounds like "high fidelity" is a misnomer if lifeless and sterile audio is what you get
>>1870537not sure if bait. what do you mean by "warmth"? even harmonics? or compression due to sagging? you can go digital and reproduce any waveform.
>>1868690wait, transistors??? for warmth?? you need tubes!
>>1870543>lifeless and sterileYou're listening to bad music if you need to fuck up its playback it to enjoy it
>>1870544>you can go digital and reproduce any waveform.Thats good, because we all know that "accurate" listening is fatiguing and you cant do it for very longIts not pleasing at all to the ears
>>1870543>lifeless and sterile audio is what you getWhy would you want to hear your equipment making noise rather than the sound the artist intended? Truly remarkable amounts of cope.
>>1870549I genuinely can't tell if this is an ironic post.
>>1870551Have you never done critical listening on very high quality equipment?
>>1870550Having your audio be pleasant to the ears as opposed to shrill because of mastering made for the general public?I dont know, why would I want that anon?
>>1870553>>1870555Are you arguing it's better to listen to music on worse equipment? That's hilarious>mastering made for the general public>muh special ears
>>1868539Do ***NOT*** short-circuit Li+ batteries!
>>1870543>>1870550Not him, and not you, I am another anon, but this is actually an interesting point. The sound the artist intended may already have enough "warmth". It could have been your favorite guitar piece played through a vintage tube amp. Why would you want additional "warmth" on top of the original distortion since the original recording is already pre-distorted for you. You actually need a high fidelity equipment to reproduce the original warmth, right?
>>1870555Mastering has already killed the dynamic range by compressing the sound. How are you going to unmaster it and remaster to your liking?
>>1870555Yeah, I can't stand accurate audio. I feel bad for the artists who recorded it. Perfect accuracy - must have been unbearable. I'm working on a system to intercept and record the sound that would reach my ears in day to day life, clip it like crazy, and play it back. After that I'm going to try to develop ordering a dildo from Amazon so I can fuck my own asshole instead of staying stupid shit on the internet
>>1870532I would advise to stay away from the cheap Chinese scopes, at least the USB ones and the DSO138s and similar. You’ll want 2 channels (if not 4), those single channel scopes are a joke. In general, cheap analog scopes are a fair bit better than cheap digital scopes.As for the function generator, yes your phone can work fine, so long as you can find a good app for generating signals. But you’ll be limited in amplitude output and won’t have a trigger output or a modulation input or the other handy things you get in a dedicated machine. Some Chinese function generators probably have these features, and for the price you may consider it worth upgrading. Or have that as your first project, to make a function generator.
I have this circuit in a device I own. It's extremely inefficient, so I'd like to improve it with some sort of switching voltage regulator. The only one I can get at a reasonabke price is the MC34063A, which has a maximum input voltage of 40V. Is there some way to make it work? Maybe using the existing linear voltage regulator to get down to the 40V the IC needs and then using that to get to 14.3V?Also, what could I do on the negative side? The MC34063 takes a positive Voltage, so how could I deal with that?
>>1870555I'm clearly talking about noise introduced by equipment, not issues which are speculatively introduced. Nice strawman tho, but wasn't part of my argument. Funny how you have to introduce garbage noise into my argument for you to have a point.
I want to make a robotic arm that points with a laser pointer to a input i.e. a constellation. Does anyone know any libraries or apis for star locations?
>>1870635You either need a dedicated split-rail switching controller, or "complimentary" switching controller ICs (switching equivalent of 7805/7905). That or two identical isolated buck converters chained together, I suppose.
>>1868933Don't worry, there's ALWAYS one of these guys who go>I never study and I know X, only stupid people have to study and learn X>Look mom, I'm being an elitist on the internet!Just tell them to fuck off, otherwise they will go "you HAD TO learn THAT too?" even if they don't know what they're talking about. It's a waste of time.
I'm modifying a machine in work that uses a large modular PLC.Basically I want the circuit I'm adding to switch on when a circuit that is already in the machine switches on so I was going to just tap off the same output on the PLC and use it to drive an SSR.However I just want my circuit to be steady on as long as the other circuit is running but the PLC is using PWM to vary the power to the original circuit.Is there a simple way to turn this 24V square wave into just a steady 24V, something like rectification?
>>1870706Diode + small cap should do the trick, with a discharge resistor too. If it's powering an SSR or MOSFET or anything with an insulated gate, you'll need that discharge resistor. Might want to add a transistor to it in case the cap and resistor pull too much current from the PWM wave.
>>1870707Like a transistor on the high side like pic?
>>1870708Forgot to draw discharge resistor in there
>>1870708>high sideOh, because otherwise it would be inverted? Should work fine I guess.With a discharge resistor across the capacitor too. Actually, the discharge resistor might cause the SSR to switch off really slowly and make some heat. Might need to schmitt trigger that with a comparator or logic IC or whatever.
>>1870635>It's extremely inefficient,sure, because you're using +-43V to generate +-14V. that's insane. replace the transformer for something sane and your efficiency goes way up. you can stay analog and pure instead of inserting evil death-causing high-frequency noise into your life.
>>1870635Linear regulators work better with low voltage diferences between input and output. That's why lab supplies usually have a switching pre-regulator that keeps 2-3v above the output that is followed by the linear regulator.
>>1870603I've searched on the internet and I found three candidates for my first oscilloscope:>Hantek DSO5072PCheapest of the bunch at 167€, 70MHz, widely shilled, can be hacked to 200MHz, but probes are good only up to 80MHz>Hantek DSO5102PThe only difference with the 5072 is that this is 100MHz and probes are good up to 150MHz. Equally shilled as the smaller brother. Costs 10€ more.>Hantek DSO4102CSame specs as the 5102. Has an integrated arbitrary function generator, but the layout of the knobs and buttons is ass. 200€. Not nearly as shilled as the other two.
>>1870757still can't come to terms with the fact that lab supplies are supposed to be high accuracy low noise and yet they are based on switching regulators. insane. why do people care about efficiency so much.
>>1870812>why do people care about efficiency so much.>energy = money>wasted energy = heat you have to get rid off = fans, space and copper
>>1870822sure the industry is highly competitive so of course commercial designs compromise quality for the sake of saving nickels and dimes and. But for DYI? You are not saving anything anyway. The switching technology is an absolute and utter shit when it comes to noise. Just look at the scope. It is horrific. Linear all the way. Big trannys, lots of copper, huge sinks and fans. It is bulky but high quality.
>>1870826That is like saying>veichles with wheels are terrible for moving aroundThere are switching regulators and switching regulators. If one model fits your noise requirements then I don't understand what you are talking about. And as I said, switching pre-regulators with linear outputs are a thing, so are low-noise switching converters.
>>1870757That's not true, the PSRR is higher with higher voltage drop
>>1870828I was talking about efficiency improvements, not ripple rejection. But you are correct.
>>1870829My bad.Speaking of PSRR, I have a 1.2MHz 15V switcher-> 12V linear power supply on my headphone amp and I'm still getting at least 50mV of switcher noise on my output signal. It's inaudible but I'm confused about it. Maybe some sort of poorly laid out ground plane thing - still, it seems hard to believe. Came here to vent
>>1870830Ferrite bead at the linear input?
>>1870865Maybe the next revision. I've been relying on the LC filter and decoupling caps but it seems that might be insufficient
>>1870812Any power supply worth its salt has filtered the shit out of the output. With the move towards higher frequency switching (easier to filter) and with resonant switchers becoming more common power supply noise is becoming a thing of the past.
>>1870887>With the move towards higher frequency switching (easier to filter) and with resonant switchersthat just means the noise is radiated less thru the wires and more thru the air, fucking up every sensitive project within a 37.3-inch radius.
>>1870926What the fuck are you talking about. It's just that it makes the filter components smaller and cheaper.>treating technical subjects as politicsThis is what /pol/ did to us.
>>1870830>doesn't affect the device>still complainswhat
>>1870926>37.3 inchThat seems to be very specific
>>1870746I know why it is inefficient. The problem is that I can't change the transformer, since the ±43V is used elsewhere in the circuit. My first thought was doing something similar to what >>1870757 is saying: put a switching regulator in front of the linear circuit to bring the voltage down to around 16V. But that can't work.with the only switching regulator IC I can cheaply get, since that has a maximum input voltage of 40V?Hence my question wheter it would be feasible to either run the MC34063 at 43V, or to use the existing regulator, but changing the zener so yhe output is <40V which I would then feed into the switching regulator, set to output my 14.3V.
Does this mean 32 volts flutuating between 25 and 37?Same with the 26
>>1870947>would be feasible to either run the MC34063 at 43V, or to use the existing regulator, but changing the zener so yhe output is <40Vboth are feasible. a chip rated for 40V will handle 43V 99 times out of 100. however a 5V 10W zener in series will guarantee it works 100/100 times. but what about the negative? doesnt seem doable to make another isolated negative output unless the transformer is made from two separate windings, instead of a being center tapped. unless you get a diff chip that can create dual rails like the chip in >>1870870. it's $6 at digikey, so 6 times the other chip, but still not too bad.
>>1870959>32 volts flutuating between 25 and 37?hell no, it's a range you can expect given that line voltages vary from place to place and also during the time of day.
Yo this is fucked jbl flip 4, the micro usb got fucked so i tried to replace it completle with usb cable, but I have got a problem there are two cables.... Why does micro usb have two cables how do I make this work. Sorry I am retarded
Can conventional PWM SMPS controller chips like the MC34063 or the TL494 be configured to do pulse frequency modulation (PFM) instead of PWM? Wanna make a ZCS SMPS on the cheap and I wanna know if it can be done with cheap readily available controller chips in DIP packages.
>>1870970>just use a 10W zener broThat's a fucking horrible solution.
>>1870959Nah, AC is fluctuating anyway.If you measure it with a multimeter you're measuring the RMS voltage.You should get a pretty steady reading it just mightn't be 32 volts.It could be anywhere from 27 to 37V but it should be steady
>>1871008>It could be anywhere from 27 to 37V but it should be steadyGreat, thanks! I just changed my old multimeter for a new one and I'm still trying to figure things out...
>>1870938I don't want my 1kHz sine wave to be an inch thick on my scope. It makes me feel bad
>>1870970>5V 10W zener3.6V zener should be enough. At 100mA, that's 360mW, so a standard 0.5W one should be fine.That way I would lose 0.36W in the Zener and 0.13W in the transistor if I use the switching regulator to get 16V.I don't know about the efficiency of the switching regulator, but it has to be better than the 2W of loss I get currently.The loss on the negative side iis only 0.5W due to the low current, so it's not such a big problem.>>1871003Why?
>>1870990One 5V, one 0V, if I understand correctly. A power only cable, as opposed to a power+data cable that has 4 or 5 isolated conductors. Do you need to transfer data?
>>1871024>hurr what is HF Reject
>>1871040I dont need to transfere data only to make power. Is there name to a kable you would sugest i use? I am really lost in this stuff
>>1871062A two wire cable should be able to transfer power just fine. Google image search for “micro USB pinout”. I think V+ and GND were on opposite sides, tracing the circuit should tell you which is which just from context. Also note that you may need some form of strain relief after soldering two wires directly onto where the micro USB socket used to be. I don’t think you’ll need resistors across the data pins, which is the case for some USB power applications.
>>1871227Not the guy you're responding to but I have a rasp pi v4 that will end up getting hooked up to a 12V battery backup solution I'm custom designing. On board will be a switching converter which regulates that down to 5V for the rasp pi. That normally derives its power from USB-C. Can I just supply it with only the +5VDC and ground or do I need a smart charger with USB-PD capability in order to even supply current to it? If so can I power it via GPIO pins instead?
I am reading and writing signals with bits that last 3us. The device Im connected to sends a signal about every 2ms and I absolutely cannot miss it so interrupts are disabled while I am reading and writing. I also want to debounce a push button at the same time with interrupts. Timing is critical here as well just not as much. Im actually using a dualcore mcu right now so this wouldnt be too much of a problem but I want to make a circuit based on a different chip so I dont want to rely on that. This is also partly why I cant have a hardware solution to debounce.Any suggestions, tips, pointers?
>>1871296What do you mean?>timing is critical here as well just not as muchIs it not as critical to the point that it can wait until the read/write is over?
>>1871265Connect the buck converter directly to the GPIO pins. It should be able to supply 3A continuous minimum with the voltage set a little high (5.1-5.2V depending on wire gauge/length)
Is this 3 phase?
>>1871330maybe. often you'll see 3 wires above which are around 12,000V three phase. then 2 of those phases go to the transformer, which puts out 240V split-phase (i.e. center tapped). that goes into your house.if you have a factory and you need 3-phase power, they'll put up a special xformer that'll take 3-phase in and give 3-phase out.
>>1871336Well I don't NEED 3ph but I want it. Buying a house and the 3ph tools are better. Running 3ph is expensive as fuck apparently but those wires run by house so would be "cheap" to run it 100ft to the garage. Probably.
>>1871339The three phase would be the INPUT to the transformer, not the output from it. That means you're talking somewhere in the range of 4kV-30kV. Attempting to tap into those lines would not only be illegal it would be suicide.
>>1871342I didn't mean I was going to do it myself in the night but have the power company bring 3ph to my building. If possible.
>>1871349Oh, I see, I misread that.
>>1871349dunno about your jurisdiction, but around here if you have 3-phase installed for business purposes, then you can install your own transformer inside the house to convert that 3-phase to 240V split-phase to power the whole house. and you would do that because then your entire electrical bill, for both home and shop, become a business expense. so, if your tax rate is 30% on biz profits, you save 30% of your electrical bill.
>>1871371I'll have to ask a local elechicken.How many years can I go without making a profit before the tax man come knocking? Microsoft still hasn't made a single penny in profit on Xbox.
>>1871330>blurry picture where you can't even count wiresok
>>1871412Its Google maps, best I can do in the middle of the night.
>>18714143ph transformers have 6 connectors (Atleast here in brazil). I believe some older instalations (and sparsely populated places) use single phase branches for group of houses/streets but most of them just use a 3ph and balance each phase so they have a similar load. You should contact you utility company, they are usually efficient and clear with this sort of information. (Max load for a plot of so and so sizes, location of HV lines, how much it costs for a 3ph or 1ph connection to diferent sorts of enterprises etc)>electrician question>/ohm/>3ph tools better?
>>1871422Yeah the 3 phase machines are built like tanks for industrial use unlike consumer grade 1 phase machines. At least for what tools I'm looking at.
>>1871414I'm on a standard 3~/400/N/PE 32A distribution like every home here. Sockets are 230V 50Hz 16A. 20kW water heater has direct 3ph connection.
>>1871440If that is the case then just contact the utility company and they'll tell what you need to do/pay. If even in brazil they manage to get on time, install shit correctly I think for you in the first world it's gonna be ok.>>1871433YOu are putting the carts ahead of the animals my friend, if you want a good single phase tool then you can find one. The number of phases is related to the kind of motor used and their power and torque ratings and also simply due the fact that for some power ratings you need three phasic stuff unless you want wires ticker than your torso.
>>1871461Well they don't make a 1ph 16" joiner, I'd have to get a smaller 12" if I wanted a 1ph tool.
>>1871414I see 2 wires + CATV, so probably no>>1871479I worked a little while in a shop that had some 3 phase tools running on split phase using a rotary converter and some using a VFD. I believe the VFD gave a little more power. The guy who ran the shop said he had to get the power company to install a bigger transformer because the fuses on the pole kept blowing.
I finished the pcb and now it's time to connect all the viasHonestly though, It's great for smaller pcbs, but for bigger pcbs like this i think i will just bite the bullet next time and wait a couple of weeks for the chink fab house to make it. It just consumes too much time to do that shit by hand for a larger project.
Anyone ever go to school for an electricians certificate? I would like to learn the trade, but dont know if the cost is worth it.
>>1868373I'm new to electronics. Should I go for a hakko or a chinese soldering station?I've put together a list. Is this good?
>>1871649https://www.amazon.com/hz/wishlist/ls/23OPPHF42YI0Z?ref_=wl_sharewhoops forgot the list
>>1871649This is /ohm/ approved cheap chink shit that's actually good for the money >Quicko/Ksger T12 soldering station and a pack of T12 tips (and a base) >Aneng AN8008 or AN8009Also, get a set of ESD safe tweezers, they're cheap and useful.
>>1871659>2020>people still waste time and money on ESD shit instead of just working barefootedtop kek
I don't know anything about thyristors and I'm confused by this circuit. 1. Wouldn't the thyristor get triggered into conduction only during the positive half-wave of the AC line? 2. How exactly would the microcontroller know the exact moment (zero crossings) to trigger the thyristor to control the light bulb brightness?
How are the books that are in the OP?
>>1871679>1. Wouldn't the thyristor get triggered into conduction only during the positive half-wave of the AC line? Why you think so?>magic box does thing>How exactly would the microcontroller know the exact moment (zero crossings) to trigger the thyristor to control the light bulb brightness?PR senses light. Probably the uC senses the 60hz flicker and works with that
>>1871679>How exactly would the microcontroller know the exact moment (zero crossings) to trigger the thyristor to control the light bulb brightness?it doesnt know and doesnt care. zero-crossing detection is great for several reasons but i'd suggest 95% of triacs circuits in use dont implement it. also, it's way more likely that there's no brightness control, just on/off. cnat tell without source code, for the (ahahahahah) Freescale 68908 micro.>>1871694>How are the books that are in the OP?they have received ohm's highest recommendation. i.e. they suck cocks. feel free to pirate-bay some better ones, which only you can recognize coz you are a unique learner, like everyone else.
>>1871521How much force can those helping hands withstand? My ones are similar (probably cheaper) and they just deflect at the amount of force required to solder a joint.>>1871679That's a TRIAC, not an SCR. If you look at the circuit diagram of a TRIAC, you should see that it should be able to be triggered by a positive pulse regardless of whether there's +120V or -120V at its far leg. I think. As for the sensing, either it picks up the ripple from its input, or can sense the difference in load current through the TRIAC itself. But usually I'd expect to see a seperate input with a seperate (unfiltered) rectifier + zener as a zero-crossing input.
Having some issues with quartz crystal designUsing it with STPM32, datasheet is not overly helpful and neither is reference designSo using 16MHz 8pF small oscillator managed to get it working by removing load capacitors and adding high value feedback resistorIs there some cheap way to measure crystal pins?Some cheap 100x probe I have seem to have too much capacitance, can still somewhat see crystal waveform but chip is not workingOr should I just fuck it and call it a day if everything is working with clkout giving good good output?>>1871679triac's trigger when current is flowing through gate and it doesn't matter when you trigger it, just voltage should be high enough if you want it to latchZero cross is unlikely to be included with schematic you posted, but brightness control is most likely done by measuring brightness with photoresistor and then adjusting on/off cycles via software, half-cycle is known so some basic logic and your'e good
So I need dual rail outputs for my project and I figured why not do it all on one IC instead of separate. LTC3523 seems to fit except for one problem. I want to double check with someone more experienced. Plan is use 4 primary alkaline cells : 3 in series one parallel for VCC = 4.5V. One output will be charging li-ion 5V, 500 mA. Now here's the problem: in LTC3523 datasheet it says Isw=600mA I guess it's switching current so 500 mA is safe is that right? The other output will be stepped down to 2V, 200mA. Anyways this is my first time doing something like this so I could be way off
>>1871794>Isw=600mA I guess it's switching current so 500 mA is safe is that rightThis is a bit confusing. At first glance I'd assume Isw is maximum instantaneous switching current, which will be higher than the output current. The Current Limit section specifies 1000mA peak so I don't know Isw is referring to.Putting that aside, from this graph it looks like this IC won't work.
>>1871794>>1871800It's minimum guaranteed switching current which which might be useful to know for peak power consumptionBut yes, this chip is not suited for your application especially with batteries powering the device becaue Iout vs Vin is terrible when running at almost max power
>>1871807>>1871800thanks. Yeah I made it overcomplicated too. Since my input voltage is ~6V and outputs: 2V, 5V two step-down with cells in series should be better. The reason I want good regulator design is I'm limited to 4 alkaline cells to run a lot of shit for as long as possible. The 5V output will be the most taxed. Are switching controllers instead of regulators worth investigating or is it overcomplicating? Thinking there could be sleep functionality and optimizations that would make a difference
>>1871820That's overcomplicating it. The main difference is that the switch isn't in the IC with a controller. You don't need much power so there's no need to bring it outside
>>1871823Okay I'm going down to two single output regulators. LTC1707 looks good for both cases.>Vin1 = 6V>Vout1 = 5V @500mAh>Vout2 = 2.5V @200mAhI'll check it over again when I'm not tired before ordering things. Also I think LTC datasheets are easiest to read and TI the hardest
Red pill me on resonant smps topologies, are they worth considering to use or build as a hobbyist? Are there any good yt channels doing in-depth dives into smps topologies?
>>1871851Yes, especially if you need a smps.they are extremely easy.https://www.analog.com/en/app-notes/an-140.html
>>1871851There are decent yt videos on the general common SMPS topologies. There is obviously loads of information available on non-isolated PWM topologies like buck and boost since they're fairly simple and easy to explain. The isolated PWM stuff is harder to find more detailed info on though forward, flyback, push-pull, half-bridge, and full bridge are probably explored a bit in some videos and are thoroughly covered in various bits of literature (Only DCM tends to be covered in detail, I find info on CCM designs is typically tacked on as a footnote and not explored in detail).Resonant forward converters as well as resonant half/full bridge, and SCR based converters (all PFM) are very hard to find any info on. Give up on youtube, you won't find anything useful. Forget about books too, it's not usually covered in great detail. You're basically restricted to various application notes and papers you find online to glean any information out of. Most of it is very technical so if you're kind of new to electronics it'll be hard to decipher. Also if you actually build these circuits you need ways to be able to characterize things like your transformer's leakage inductance because it's actually an important design parameter in LLC converters. At the cheapest end you need a GOOD LCR meter to do it or better yet a vector impedance analyzer or VNA. Anyway, it gets complex fast. There's a bit more info on PFM based buck and boost circuits though since they're simpler and not that dissimilar to their PWM counterparts, the controller IC is very different internally but the external parts don't change much.
>>1871770>>1871713There is a filament lamp and a photoresistor
>>1871679>>1872058Technically it could figure out the zero-crossing from an internal high-pass filter on the LDR, since lighting will flicker slightly at 100/120Hz. Maybe with some digital rendition of a PLL. If it's just a general-purpose MCU then it couldn't do zero-crossing sensing through the power pin, not to mention the capacitive dropper shifting the phase of it. You pretty much require zero-crossing to use a TRIAC from what I've seen.
>>1871770>How much force can those helping hands withstand?a lot i have to push down pretty hard to make them spin
>>1872089must be made of non cheese-grade steel then, mine are junky.
>>1872069>You pretty much require zero-crossing to use a TRIAC from what I've seen.that's complete nonsense. 1 billion installed light dimmers say otherwise.
>>1871770>My ones are similar (probably cheaper) and they just deflect at the amount of force required to solder a joint.Those helping hands are very cheap. "Powerfix" is a Lidl brand.
>>1872111I meant to include all phase-fired circuits with my statement, oops. So a better term for both electronically timed 0-crossing designs and RC delayed phase-fired designs would be "synchronous TRIAC circuits". Unless you know of a circuit that can use a TRIAC for dimming with an asynchronous driver (i.e. normal PWM)? I'm pretty sure normal PWM will give all sorts of issues, even if you avoid aliasing.
anyone made a synth for percussion unstruments before? analog circuits that can sound like drums, snare drums, cymbals, that sort of thing. be nice to avoid prepackaged drum samples without having to invest in an actual drum set, plus it might give me a lot more freedom as to what my drums sound like.
>>1872111good luck using that with a led
>>1872126They were not deisgned for LEDs>>1872120I think there are/were analog drum machines. No idea of how they work.
>>1872119>phase-firedPhase-triggered sounds more rational, nothing is burning here. Would you call a DIAC a fire diode?
>>1872137>Would you call a DIAC a fire diode?Seems pretty rad
>>1872128I think he's referring to mains LED "bulbs" If they have an integrated SMPS, then a TRIAC dimmer will do nothing for most of the phase. If you turn the dimmer way down, you'd get some unpredictable behaviour like flickering or overheating or whatever as the line converter IC ceases to start up properly. A capacitive dropper LED will work with a dimmer to some extent, but not that well, might get nasty current spikes. A HV LED string on a full-bridge with a linear current regulator will work just fine, but even at full brightness it will be flickery without any filter caps, but adding those filter caps will make it fail to dim on a TRIAC dimmer for the first 90° of phase, and only work on the next half, but flickery.I suspect the best ones have an SMPS that interprets the chopped-up waveform of a TRIAC dimmer and adjusts its output current accordingly, similarly to the PWM pin on a servo.>>1872137"fired" as a verb doesn't imply combustion or munitions any more than "trigger" does.
>>1872142I know, and I said that that typical kind of dimmer was not designed for LEDs. Is this pedantic posting hours?
>>1872146everybody uses led bulbs, therefore what you posted is completely uselessget with the times grandpa, it's not 1950s anymore
>>1872146>that typical kind of dimmerI've heard that other types are better for LEDs, but which ones? I can't imagine that a trailing-edge dimmer is any better for anything other than RFI. Do they just use higher frequency PWM across both halves of the waveform, using MOSFETs or whatever?
>>1872158led dimmers use zero crossing detections and trigger a triac 100 times per second if the AC is running at 50Hz, the delay in triggering after each crossing determines the brightness. The led has to support this.
>spend months acquiring tools, and knowledge>no actual serving purpose other than useless gimmicksI actually learnt this shit with some weird Jason Bourne fantasy that one day I’d require this knowledge.
>>1872151I didn't post any diagrams you retard. And the original guys here>>1872111and here>>1871679had the filament lamp symbol. Calibrate your eyes>>1872158There are several technologies, most power electronics slightly more complicated than a flyback are active research and design topics so the market is still changing. (You can see this with how kW-MW power electronic modules have no standard whatsoever).Anyhow, the best LED dimmers are the ones that come with the lamp, usually they do this on the DC side of things by just limiting the current. The problem is you can't just buy one of those and install.
Hello. I am aiming to connect an old monochrome CRT to my desktop and I have a couple of questions. It only takes composite input, and is designed for the BBC micro era computers. What kind of video signal is the monitor expecting, is it normal composite pal/ntsc or something specific to these monitors? If I buy a very old GPU with composite outputs, will these work together? Does anyone know what the horizontal frequency of these composite monitors is? I understand it won't be easy, but is it possible?Alternatively, I'd thought about connecting it to either the composite output of my raspberry pi arduino, but this limits what I can display on it.
>>1872221*raspberry pi OR arduino
How's library compatibility between branches of ESP?I wanna run a ESP8266 library on an ESP32https://github.com/antevir/OrviboS20_Arduino
>>1872221>is it normal composite pal/ntsc or something specific to these monitors?unless it has a SCART connector, then it's just good old composite video.>If I buy a very old GPU with composite outputs, will these work together? yes. you can also get converters: HDMI-to-composite, VGA-to-composite, etc.>the horizontal frequency of these composite monitors 15Khz for ancient models, and 30Khz for newer ones. high-end monitors will accept a wide range.>to either the composite output of my raspberry pi arduinoarduino doesnt have any video outputs, but the Pi 1,2,3 work fine. dunno if they still have it on RasPi 4.
>>1872252Thanks for the answers. The company making the monitor closed in 1985, so would that make it a 15khz set do you think? There is a library for composite video from an arduino, you just have to wire it up yourself:https://tronixstuff.com/2011/05/30/tutorial-video-output-from-your-arduino/The RPI 4 also still has the composite out. How low resolution do the HDMI>composite adaptors go?
>>1872226No, totally different internally.
>>1868539You can achieve the same with a smaller relay, turning on a car starter relay. Some mofo did that before, it works.
>>1869399might sound daft but look for lightbulbs inside the organ, i know that some organs used lightbulbs as a resistor to compress sound but I don't know if its in yours.
im trying to build UPS for 1A usb device. is this correct approach? if yes then should i bother with mos driver ic for faster gate discharge?
>>1872226it is unoptimised arduino lib so most likely it ll work with minor changes
>>1872178make guitar pedals and sell them to post-rock artists for 10 times more than you bought the parts forbonus points if you make a yt channel showing off the effects>>1872210>the best LED dimmers are the ones that come with the lamp, usually they do this on the DC side of things by just limiting the currentThat's what I was thinking, no flicker that way. But doesn't it result in a slightly different hue compared to PWM? Something about the phosphors getting saturated at normal high-intensity operation. Might be talking out of my arse though. Be interesting to test.>>1872545If the +5V drops slowly (e.g. large capacitance or failing PSU), will that MOSFET enter the linear region and get hella hot? Also the PFET needs to be switched fully on even at the minimum battery voltage, and since the maximum battery voltage has to be less than 5V for the FET to reliably turn off, it's a 1S, and 3V on many a MOSFET is borderline and high resistance. Could arguably make it 2S if your charge circuit can handle it, and if the FET will still definitely be turned off at that non-zero Vgs.Also I'd see about managing to use an NMOS transistor instead, because it gives you much better options for choosing a transistor, PMOSs are significantly less common.
If my circuit will draw 9 watts, would a 12 watt power supply be safe enough or should I get an 18 watt
>>1872770rule of thumb is 2x, but 12 watts will probably be fine. It can depend, however. Some things draw a lot of power at start-up then settle into their operating load. What are you powering?
Anyone have experience with custom usb I/O devices for Windows PC? Any resources to recommend?
>>1872795Just an led lamp. Nothing fancy. The 18 watt adapter is a dollar more anyway, but out of curiosity would the 18 watt brick not get as hot as a 12 watt or is that not how that works
>order chinkshit solder station>says in US>expect it to drop ship and take 3 months to shot up>was actually in the US>shows up in like 5 days>the one order I place in an entire year on amazon takes like 10 days to ship despite prime>numirch still 4 weeks behindIt is a dark day when the chinese are now the leaders in shipping.I bet if I order tips from china they'll get lost just to spite me for this one instance of good fortune.
If I want to display an image on my oscilloscope, a raster image with scanlines and what will be easier than vector, right? With something like an LM1881. Though I don't think my scope has a Z-axis input (which I think is used to modulate the brightness of the trace), just an external trigger. Still, if I could combine the ramp of one axis with the amplified composite video signal, I could just draw a bunch of scanlines as normal for white, but draw them out of the display area for black. This would probably work fine for a black-and-white image or video signal, so long as the rising and falling edges of my video signal are steep enough. Converting to black-and-white should be easier than making a vector image, especially for a video signal.If I inverted a lower amplitude video signal on every second scanline it might be possible to get a 50%-100% continuous brightness variation as the scanlines overlap or not, maybe. No clue how I'd invert the video signal like that though, all-pass filter + a MOSFET?On that note, what would be the cheapest and most compact method of getting a downloaded (and preprocessed) video stored and constantly feeding into my scope? I don't know if portable media players have video outputs, so I'm leaning towards a cheap rpi/clone, with an HDMI-to-composite converter. Not sure if I could get audio and composite video directly out of that TRRS socket, since I'd want to put a speaker on it too.
Need suggestions for a heap and nice soldering station, whats a decent Hakko clone i can get that uses legit Hakko tips? my other option is a TS100 but i would rather get somethibg with hot air.
>>1868373look at that pansy holding the hot neck of the soldering iron that doesnt even have a head equiped. bet that faggot went to devry. that is not how you break a surface mount inductor. you have to want to remove it intact then push slightly to hard as you attempt to move it while the solder is still hot
>>1868373Why is that guy's head so small? He looks like a cartoon
>>1872582Sorry I meant general current control. PWM is just another one of those methods (albeit non--linear)
>>1872829>soldering iron that doesnt even have a head equipedThat's a hot air blower you retard.No point in complaining about an image that people have mocked for years, it's just a poorly staged stock image. But by all means, complain about the open hard drive, the soldering station's display facing the camera not the worker, the display not even on, the smell of burning flesh, the lack of workholding or even any solder or flux or tweezers or IPA, the poor perspective and focus from the background making it obviously greenscreened, and the lack of toxic vapours we've all come to know and love.
>>1872829based retarded poster
interesting article on simple analog drum machineshttp://mickeydelp.com/blog/anatomy-of-a-drum-machine?the circuit blocks it's made of are relatively simple too, mainly just simple vca and decaying sine oscillator circuits. plus a couple mcus, one for noise and one for midi and keypad controlling
>>1872545>>1872582+5V ll be usb so no large capacitance and there are cheap pmos with 0.07 omh or less at -2.5vgs. Btw i can switch pmos around (pic) right ? it wont leek though body diode or charge battery when 5V is up. And if i would end up with nmos what should i use to control it in this setup? opamp/schmit?
>>1872866>no large capacitanceI think it's 10µF max or so? At least that's for devices, not power supplies. As a USB power brick (or computer or whatever) turns off, its internal capacitors will discharge through your load, their voltage decreasing as they do so, and it's quite possible that they have 100µF or even higher.>0.07 omh or less at -2.5vgsThat's fine. I'm not only worried about specs but availability also, being someone who buys parts from alibay. If you're fine ordering from digikey or LCSC (or actually managed to find those specs on aliexpress) then no worries.Also why do you need a MOSFET in the first place? Would two diodes alone not work fine, or am I missing something? Or do you just want to avoid the diode drop by using what's effectively an ideal diode circuit? Because the first circuit you posted doesn't do that.
>>1872835>>1872834>falling for 3/10 trollsboys, i am dissapoint
>>1872874>i was just pretending to be retarded
>>1872871i was trying to make it as efficient as possible at least battery side and yeah first image was kinda retarded. Guess i ll have to get some pmos and test how bad is it with 100uf as calculations and analong is not my strong side...
>>1872819Okay it looks like my scope has an "External Blanking Input" BNC on the back, which if I understand IS a z-axis input. Neat, I guess.Looks like trying to make my own composite clock divider instead of buying an LM1881 or similar is a bad idea though.>>1872882just spice it, friend
>>1872582>make guitar pedals and sell them to post-rock artists for 10 times more than you bought the parts forIs there actually money in this? I've wanted to do it since making a tremolo back in college but it seems like the market is flooded with fuzz pedals where the main distinguishing factor is the paint job. I don't think I could bring myself to invent enough audiophool wank to fill a product page.>bonus points if you make a yt channel showing off the effectsI think my guitar skills would not help sell pedals.
time to assemble this shit, i love it when a pcb comes togetheri also decided to raise the temp of my iron from 300°C to 330°C for this because i like to live dangerouslyi swear to god, if this shit doesn't work after all the work i put into it i'm going to take a shower with a running toaster
>>1872888I think a couple years after corona people will have more disposable income to waste with pedals, but I've managed to sell one once. The finishing is the most important for music fags, and also how much you can bullshit them.
>>1872866gate voltage is relative to the source pin, so I believe this will give you weird hysteresis if the boost input ever goes low. >>1872882>i was trying to make it as efficient as possibleLook up oring controllers, they are designed for this situation.
>>1872890You are the plated hole dude? Why not just drill the holes and make vias look a bit diferent from regular holes and solder clipped component legs inside them? I used to do that, worked quite well.
>>1872899>boost input ever goes lowwait isnt it always VBatt - bodyDiodeDrop? if battery ever goes lower than 3V it wont supply enough current anyway.>Oring controllerlooks interesting but i feel like it is overengineering for 5V 1A and would rather avoid ordering obscure components
>>1872905i never attempted to plate the holes, it wold take nasty chemicals and shit and that is way too much work for an uncertain outcome, i just connect the vias with wires
>>1872919>wait isnt it always VBatt - bodyDiodeDrop?Yeah you're right, I missed that. As long as the turn on voltage is less than (battery voltage - body diode drop) it should have positive feedback that turns the mosfet the rest of the way on. If the battery is >=3v you'll want a mosfet that turns on a good amount by ~2.3v so you'll have to choose carefully.
What would be a good heat sink so I don't have to sit and wait as long for a soldering iron to cool down after I'm done using it? I was thinking just a few inches of sand in a cup.
>>1872983how fast you want it to cool down? damp sponge could work just dont try to 280 to 30C at once. as for sand i would rather not put solder iron tip into sand as you dont want sand in your solder joints. Also not sure if just me but it feels like that t12 tips cool down faster than regular heating one, on the other hand I just leave soldering iron on work table and dont bother so cant really tell.
>>1872983Heat pipe/coil attached to the cold side of a peltier module with an inline reciprocating pump to circulate coolant.
Is there anything like the VK2828U7G5LF but with bluetooth?
>>1872993Cool to the touch in 5 minutes maybe. I heard rapid cooling via water reduces the life off the tips which makes sense, then again it's chinese and sand probably wouldn't help either. I just want to know it's cool by the time I'm done cleaning so I can leave without thinking something is on fire.
>>1873009just get or make soldering iron stand. Cooling with damp sponge wont damage if you dont go full retard and try to 280C - room temperature in 5s. however if you just leave it unpluged in about 1-2mins it ll drop bellow 200C and wont even be able to ignite paper so worst case you ll melt some plastic or synth fiber but no fire
Just soldered this bad boy. I've always been afraid of soldering but I've finally got the hang of it! I know some of the joints might have a little too much or too little solder but I'm just glad I managed to do it.
I want to mod my Kobo mini. Quick question: https://blueflyvario.blogspot.com/2017/01/blueflyvariobluetoothusbv12-released.html I want to buy this for it's bluetooth+gps capability. It comes with a a battery. If I say upgrade the kobo mini battery to https://www.aliexpress.com/item/32791910883.html a 3000mah battery, will I still need to power the module?
>>1873030Looking good anon, is that an arduino uno or something?
>>1873030i bet that IC is factory soldered you lying sack of potatoes
>>1873039lqfp is not that hard to solder just flux
>>1873050No. The joints are too clean. You are clearly lying. Please just stop.
>>1873061not him. have you ever soldered smd? its not that hard with proper tools. BUT looking at throughhole most likely he only solder the pins
>>1873032I don't understand what these things have to do with each other. You are going to upgrade the kobo battery and then use the old kobo battery in the altimeter? Or you are going to plug the altimeter into the kobo? Or you are going to upgrade the kobo battery and then connect the altimeter to the kobo via bluetooth?
>>1873071>have you ever soldered smdyes, i have visited this hell couple of times
>>1873034Thanks. It's a teensy LC. I'm trying to make a library for the MAX7219 to drive an LED matrix pic related.>>1873039If you look at the previous photo the top left pin has too much solder. If it were factory soldered why wouldn't the other pins be soldered as well? Look at any pre-soldered teensy and the other pins will be soldered. I'm flattered that you think I'm that good lol.
>>1873083you should get good iron, flux, fan, paste and revisit that hell. after couple boards you ll realise that even qfn soldering is better than throughole
/b/ro here this is amazing. Does anybody have any experience with LED issues in cars? >93 Toyota pickup>Aftermarket taillights>Both have running light>Right turn signal/brake won't work>hear a click whenever the signal is activeThinking it could be a resistors blown out but I'm electrically challenged and angry pixies scare me
>>1873095>resistors blown ouuhmmm what? are you using portable suns as turn signals? string of 1W leds are not going to burn a resistor. It's probably a loose wire, happens all the time on cars.
>>1873109>>1873095pretty sure he ment fuse but it cant be one as usually right and left brake lights are on the same one. its most likely lose or burned/cut wire. check connections if you dont see anyting obvious then get mulimeter and find car wiring diagram
>>1873109The issue started when I failed to realize how unsecure the battery was the ground wire was in the battery. So there was no ground for while and just getting it raw. I check the wires :c
>>1873111Fuses and wires are in good condition. Even bent the fuse pins a little for better contact.
>>1873113absence of connection to the negative pole will simply mean there will be no power. it is in no way damaging to anything.it can be anything, it's either bad wire, burned leds, or a dead chip somewhere on the car's motherboard, and they will charge you outta ass to fix that one
> how unsecure the battery was the ground wire was in the battery. So there was no ground for whileif there is no closed loop between + and gnd current wont flow or do you mean that it was connecting on and off
>>1873120additionaly, get a multimeter, turn the lights on and start going down the chain, starting at the battery, then fuse box etc to find out where the juice stops flowing. make sure the multimeter is in voltage mode or you will be very sad
>>1873122The ground wire Literally ripped off. And I didn't notice bc life. So the car would literally die and not turn on at a stop or if I stalled out. (it needed a lot of work in the early days of ownership) Also to everyone else the information is incredible I really do appreciate it.
>>1873123Noted and gonna have to just grow up and do it. Thank you for your help. With this gents. So what's the best plan of action. An Anon said to start at the battery. I'll look up a wiring diagram and see I can make sense. This thing has had a lot of hobbyists adding little accessories here and there so the wiring is a cluster fuck.
>>1873133the first thing you want to check with the multimeter is the connection at the lights, if there is power there it means the leds are dead, or have bad solder joint
>>1873133start from car to LED wires and make sure that GND WIRE IS CONNECTED TO GND (car chassis is usually ground) and that you actually get 0 at positive WHEN IT SHOULD BE ON
>>1873080the bluflyvario comes with a battery. I have a default battery in the kobo. I want to buy a new 30000mah battery for the kobo.Essentially, does the bluflyvario have to have its separate battery or can I power the blurflyvario with the new 30000mah battery that I'm buying
>>1873166if both of them require same voltage battery then most likely yes
>>1873169thanks for answering. I asked an 'or' question, which thing were you referring to? I'm guessing the latter.
>>1873138>>1873136Based Anons. Thank you for the tips. Will probably come back and newfag on this board.
>>1873085>top left pinHe said the IC, the QFN48 teensy, not the 0.1" pin headers.
>>1873211Oh shit I'm an idiot.
I have an air blower for a wood stove that blows too damn fast.I see a lot of conflicting information online about whether just putting a resistor in series will slow it down, or if a triac dimmer switch would work. My understanding is that the best or only way to do it would be to adjust the frequency.Do they make small knob sized variac type devices to do this? Would a diode not half rectify the AC and give me half the RPMs?
>>1873219>I see a lot of conflicting information onlinethat's coz there's a greater number of motor types than there are genders, and they all need to be treated differently. most likely you have an AC induction motor, coz those are the type that are very quiet. if so, they're fixed speed. if you put a resistor, nothing happens. if you put a dimmer, it MAY work, but in an odd way. i.e. you'll get some speed control but not continuously variable speed. changing frequency will work, but VFDs are not exactly common or cheap. best thing to do is to live with it.
i got a pi zero and a knock off arduino. the pi zero only has micro usb slots. the arduino just has a usb b slot. I connected the tx and rx lines to the arduino but do i need to power it too? can i do that with the pi gpio? how
>>1873333if you wanna power them together, just run 2 jumpers, from +5 to +5 and GND to GND on the expansion connectors. you can power either one, and the other one gets power too. however, you'd have to be careful with the power jack on the arduino to not overload the 5V regulator. the Pi can take about an amp, so that may be too much for the arduino regulator. going the other way should be okay as long as you apply power to the Raspi at the 5V IO pin, and not at the micro USB, coz the USB power input is fused, and you may blow the fuse.
>>1873349hmm yeah i read that connecting the 5v requires a logic gate. i'm new to the stuff and don't have one and i'm lazy and impatient.i'll try powering the arduino first, i have it working the other way around right now
In need of a soldering station, will be working on audio equipment (pedals, amps, etc). Want something made in the USA, willing to pay extra. Is something like this Pace a good choice?
>>1873373also looking for a multimeter, but it seems like unless I buy a $400 Fluke I can't get something American. Not sure what to buy as I'm really new to electronics, I'm trying to look up what resolution I'll need.
>>1873414Get a bench multimeter instead of a handheld. You can get used Fluke and Agilent bench DMMs for cheaper than a new Fluke handheld meter and they will generally be much better meters, especially if you're doing lower current/small signal stuff.
Pulse waves are cool. A pulse with a duty cycle of 1/3 creates a node at the third harmonic, and every 3rd harmonic after that. A pulse with a duty cycle of 1/5 creates a node at the fifth harmonic, and every 5th harmonic after that.Strictly speaking, a square wave just creates a node at the second harmonic, and every 2nd harmonic after that.Is there any way to apply this to filters, or phasors, or flangers or anything else like that?Pic rel is a 10% duty cycle
>>1873512That's interesting. I don't think you could meaningfully apply those harmonics with a filter, though I'd try filtering out groups of those harmonics just to see what you get. Might be able to do some interesting stuff with additive synthesis though.
>>1873523I was thinking you could use it as a multiplier for an arbitrary signal, like an active notch filter of some sort, but I have no idea where to start in practice
>>1868407Oh hey don't worry he was talking about some other zipper head
>>1873527For a VCF? I think its low-frequency harmonics would make much more of an impact than its higher frequency harmonics. But what I would try doing is running a variable-duty-cycle VCO as part of a PLL, filter off the lower-order harmonics, and add them to the PLL's source waveform. Might need a VCF for that too though, to keep the corner freq in the right place. Trying to replicate the same thing with triangle/sawtooth waves of different skew would reduce the need for a HPF.PLLs are cool.
>>1873527You can use switching as a way of mixing signals together, there are also some PWM volume adjusters for sound applications. They are good for sound shit because you don't need to filter out the varying high frequency
>>1873373The one you posted is the first I've heard of an iron made in USA. Seeing as we don't make anything here we also tend not to make the tools for making things.Watch out for the tips, they seem to be following the razor blade model.
>>1873639I don't understand this tip meme. My chinkshit tips have lasted me ages with no problems and I treat them like shit.What does a bad tip even do? bead and drip solder?
>>1873643doesn't get covered in solder properly then it makes very annoying to try to solder things.
>>1873643Yeah, I've been using the same tip for years but I think it varies across different tips. Thinner coating means better heat transfer but they also wear out quicker, so the "high quality" tips may actually wear out faster. I had one tip that basically got shorter until there was nothing left. Once you get a hole in the coating, the inside stuff (copper?) just dissolves or burns off pretty quickly. The solder also doesn't wet properly because it corrodes instantly.
>>1873219Most smaller fan motors are squirrel cage types and like >>1873254 mentioned a dimmer may work but you increase the likelyhood of burning it up and the torque become unpredictable. The only way to control these properly is with a VFD as induction motors are frequency dependent, not voltage, and a dimmer makes it worse as it controls the time the load recieves power instead of the amount.
>>1873763>>1873219A resistor would help. Might have problems starting the motor so you'd have to see the power rating, motor type and operating conditions.
>>1873767For a universal motor, yes it would, but so would a dimmer in that case. A resistor is not the correct solution in this application, induction motors are a different animal altogether and using a resistor could cause failure, not to mention who knows how many VA the motor is.
>>1873767>resistor would helpor a light bulb in series
>>1873333i also can't upload code to the arduino only when I plug in the pi zero to the tx/rx connections. i have pi's tx going to arduino's rx and pi's rx going to arduino's tx, i think that's right. but i'm reading that you need a logic gate for those connections? can anyone explain?this is my first time trying to make a project without instructions
>>1873856are the grounds connected together? coz you need a common reference point to make the rx/tx signals real.
>>1873867nope, i just have the ground next to the power plugged in near the 5v pin, i'll give it a try
>>1873775Resistors are (were) used to control induction motors. As I said, it's not an ideal solution. They work best with 3ph machines so probably will cause problems with a 1ph machines>how many vaYes, that's why I said he'd have to check the power rating and motor class.>>1873802Also, but again. Depends on the rating.
>>1873872They are mostly used during start-up positions to allow higher torques and mostly with wound rotors. Anyhow, anon has the motor with him, he can play as he want as long as he keeps aware of the heat and magical smoke and until we have more information we can all talk out of our asses about who read more on the subject.
Considering building usb hub just because, found some microchip eval board that almost looks idealBut UPD350 is not power management IC which is kind of problematicSo I assume PM-PD is essentialy buck converter with variable feedback controlled by UPD350?Is bidirectional buck-boost worth trying to do?>>1873353>>1873856Depends on what arduino board you have and what exactly are you trying to doIf you are trying to program arduino board via raspberry pi, you need to connect reset pin as well since chip programming via tx/rx is done by arduino bootloaderAnother point - what board you have. If it's uno r3 where chip is powered by 5V, then you need logic level shifter since arduino has atmega328, in datasheet minimum input voltage is 0.9*VCC (for 5V this means 4.5V), while raspberry pi has 3.3V supply so well below minimum required for uno r3 so most likely signal is going to be undefinedAlso I'm not sure if raspberry pi gpios are 5v tolerant or not, another thing you should consider
>>1873892i'm powering the pi via the arduino as the other helpful anon suggestedi've been trying an official arduino uno and also an inland uno r3. i bought them both around the same time and they look identical so i assume the arduino is r3 too.i'll try the reset pin too. the ground didn't do anything. where does reset go to on the pi gpio?
>>1873901do not connect pi zero to uno, uno operates at 5V and pi zero at 3.3V (for gpios)Like I said - I'm not sure if pi zero has 5V tolerant gpios (some clamping diodes will be present but not sure how much they can withstand)At least add some resistor, 2k at least, in series between pins so current is limited in worst case.Also my mistake - logic high is 0.6*VCC for uno boards, so this would be 3V minimum, so arduino at least should detect data coming from raspberry pi, but I'm not sure if it will be visible on serial monitorBut still, for programming arduino via pi zero you need to be able to reset chip, there is reset pin on uno header. For more information you'll need to google, there are many examples of OTA (different hosts, like pi, esp32 etc) updates for arduino via tx/rx, some should go in depth on operation and implementation
>>1873922>uno operates at 5V and pi zero at 3.3V (for gpios)can't i just use the 3.3 v pin from the arduino to pi then?
>>1873881I come here for the bants, most places don't allow for silly pissing contests.
>>1873219>>1873763Capacitive dropper? Can't see it being any worse than a resistor at least, and it wouldn't overheat. You'd need a big capacitor though so it probably isn't worth it.>>1873775>using a resistor could cause failureI take it you mean the starter/run winding / shaded poles not being sufficient for starting the motor due to the lower current? It wouldn't burn the motor up for at least a few seconds, which is more than enough time to do a test run and see if it works with your finger on the off-switch.>>1873856Wasn't there something about a logic level shifter being needed? If rpis are 3.3V that is, can't remember if they are.>>1873892A 328p can run on 3.3V just fine, but I think it requires setting the fuses to run the oscillator slower.>>1873901There's no such thing as an arduino r3, they're made and designed by different companies, there's no design continuity between them whatsoever.>>1873931rpis have a 3.3V regulator just as an arduino has one, so rpis can run just fine on 5V fed to the right pin. But you need a logic level shifter, not just to change the power rail.
>>1873976>There's no such thing as an arduino r3, they're made and designed by different companies, there's no design continuity between them whatsoever.>>1873976>there's no design continuity between them whatsoever.now you're just being a prick
>>1873931>can't i just use the 3.3 v pin from the arduino to pi then?no. both Arduino and Raspi operate at 5V. that's the power, not the actual IO pins. and both have 3.3V regulators to power some things locally. so, you can power one from the other, but it wouldnt do to connect together the 3.3V power pins coz they'll conflict being at somewhat diff voltages.the other thing is the voltage on the IO pins. Arduino uses 5V logic inputs and outputs, whereas Raspi uses 3.3V logic. that's where you will need a conversion chip (or resistors and zeners, or transistors) to convert levels going both ways.
>>1873976His motor but I wouldn't risk it and have burnt out motors trying to do what he is albeit for a completely different application. The cheap and greasiest way I could think of is use a cheap class D amplifier and use the input with a siggen app on a phone to control the frequency. Assuming it's single phase.>here I go pissing into the wind again
>>1873996Sounds like a good candidate for a 555.
What's the best solder sucker tool design? I really don't trust the spring loaded 3$ ones.
>>1874012True, I keep forgetting about that. Plus MOSFETs are cheap and easy to come by in the power required.
>>1868673either wheelchair or a very cheap waiting room chair
>>1874054The spring loaded ones of quality like soldapullt work fine. Used for years fixing aircraft and still do at home.
Someone critique my thermocouple-to-digital circuit?This feels like overkill just to read a TC but all the prepackaged ICs on digikey are expensive or have crazy tolerances or use some crazy bus format.
>>1874187Bad resistor symbols. What's wrong with MCP96RL01T-E/MX ?
>>1874197The RL's are +/- 4*C. I'm hoping to use this for some homebrewing, so I care mostly about decent resolution in the 0-100C range.I could probably use the 9600 set of the same chip, but the I-type only goes up to 85C and the E-type is $6.76, at which point might as well see if I can build the damn thing myself
>>1868373whats the lazyology way of getting sound/voice to play with a little micro. obviously i could get get some external flash and a dac and do it that way. but im lazy is there some slave IC that i can flash music/voice recordings then tell it to play over its dac things with i2c or some shit.
>>1873996>cheap diy square wave vfdInteresting thinking, but it will need to be on mains voltage, with nice big filter caps. Or just say screw it and don't filter the input at all. Or just PWM it, did we rule out PWM for some reason or another? PWM at f>>60Hz, that is, none of that phase-fired synchronous dimming nonsense.
>>1874217There are some pretty cheap memory ICs out there, but I'm not sure if a few kb on an EEPROM would be enough. To get the audio back out of it, just have the MCU to read each value and PWM it at a sufficiently high frequency, then throw that through a low-pass filter. Basically a class-d amp without feedback. But 10kHz probably won't be fast enough, and I'm not sure if MCU PWM goes much above that, so you may need to hand-write a PWM code. Add some DSP to it too, if you want.R2R ladders are also relatively easy, and you wouldn't even need an MCU here, just a clock and a counter feeding the EEPROM's address pins.
>>1874231yeah im just going to get some flash and the onboard dac on the micro im using. easiest way to do it
>>1874247>onboard dacWell fuck, shoulda mentioned that in the beginning. What micro?
>>1874187How do you do cold junction compensation?
>>1874281i am looking at using the PIC24F08KM202
>>1874312If he's reading that analog value with an MCU, he can just connect another temp-sensor near the cold-junction and add his thermocouple ∆T to that.
>>1874312>>1874317The tmp236 is the on-chip sensor.On that diagram, the TC signal out of the inamp is labeled "tth" and the sensor's signal is labeled "tsn". They get added together by that resistor bridge on the + end of the output opamp, which shifts the signal to the output range of 0V at 0C, 5V at 120C.There won't be an MCU on this board, all of my peripherals are going on a big I2c bus over cat5 cable that runs to a raspberry pi.
>>1874318Oh neat, though I hope you're using some trimpots in order to get it calibrated. What's an MCP3021 like? Looks like a convenient IC, though I wonder what kind of current it can source in the case that you've got a few metres of cat5.
>>1874320I'm not sure yet. It's one of the cheapest ADCs on digikey but I couldn't find anything egregious on the datasheet. I'm half expecting to have the thing show up and be utterly broken because of some weird characteristic that I didn't think to check.I'll probably order an assembly of these parts tomorrow so I can breadboard the whole thing to verify.Good call on checking the bus limits. Apparently the MCP3021 is good up to 400 pF, and wikipedia lists cat5 as around 50 pF / meter. 8 meters will probably be plenty, and the 400pF limit was specified at 400kHz which I definitely do not need. Hopefully slowing it down a bit will relax that requirement.
I'm brainstorming an additive synthesiser that uses triangle waves and PLLs, here's what I've got so far. So the idea is that I have a master triangle wave, which goes into a series of these voltage-controlled phase shifter circuits (pic related) that produce a square wave with a phase offset compared to the original triangle wave. Though this phase offset only goes from -90 to +90 degrees (ever so slightly less, for stability), I can add a switch to invert the output to get the full 360 degrees. Each phase shifter will be controlled with a potentiometer and the aforementioned flipping switch, before being fed into a frequency divider, and then the phase comparator of a (triangle wave) PLL. Then I have an amplitude potentiometer on the output of each of those PLLs' VCOs, before summing all the harmonics together. So I'd be able to add a bunch of triangle waves (say, 8) together, with the ability to alter the phase and amplitude of each one, but such that this phase and amplitude shouldn't change with fundamental frequency. Just gonna use an XOR gate for each phase comparator, and probably NOR gates for my SR latches.Still don't have a VCO design though, probably just gonna do what I've got here (1 comparator schmitt trigger, 1 op-amp integrator) with a vactrol on the integrator. Any other design I can think of doesn't have a constant output amplitude.I also can't think of a way to use uber-cheap dip-switches to do the inverting (or just swapping to notQ), my thoughts keep leading me back to SPDTs, which aren't that bad I guess.Thoughts?
>>1874338Here's the waves. Naturally, the inverted reference voltage goes from +4V, down to -4, then back to 4 again. You can see the limitations I have with the maximum and minimum phase shifts; if either reference voltage gets above/below the triangle wave, it will lose lock and no longer produce a square wave at the right frequency or even a wave at all. I think ideally I'd have a very thin spike at the top of each of my triangle's peaks (and at the troughs), so I can never have that issue. Like an extra 20% of the amplitude on the top and bottom. Anyone know how to do this, without nonlinear shit like an exponential amp or anything else that also depends on voltage thresholds? Filters likely won't work either, because it's a variable frequency oscillator, but they might.Also no it won't be polyphonic, that would require duplicating the entire circuit.>>1874340TS100 shills out again I see, imagine shilling the TS100 when the updated TS80 is here.
>>1874343>TS80ts80 is inferior to ts100 in several important ways and way more expensive to bootdo NOT buy ts80, get ts100 instead
>>1874344It's also superior in several important ways. Ways which I will not elaborate in this post because I'm a paid shill who knows nothing about the actual nuances of either product.
>>1874345They hates Jesus because he spoke the truth.Go ahead and buy your crappy ts80 then kid. It's your own money and you can throw it away if you want.
>>1874338>>1874343I was also wondering whether, with those two comparators leading into an SR latch, I'd be able to use a 555 or similar. Since i need to feed a seperate reference voltage into each comparator, and have the other lead of each comparator tied together and to my triangle wave, I don't think it's possible with a 555. Maybe there are some timer ICs with more versatile pinouts.I'm trying out filtering the triangle wave in spice to just get the sharp peaks so I can add them to the waveform, but my high-pass filters are acting like low-pass filters, triangle waves are weird. Plus the phase is off by 180°.Maybe a peak-detector circuit is what I need instead, I'll look into those.Also it might actually be necessary that the phases are shifted AFTER the frequency multiplication, but I think I can do that without incurring unpredictable phase shifts from the state of the counters, probably.
Shoudn't the voltage and current on a AC power source attached to a resistor have a 180 angle offset? (So v(t)*i(t)<0)
>>1874369Yes I think so, so the power source produces power and the resistor consumes it.
>>1874369silly question. there's nothing in the makeup of a resistor to cause a phase shift. voltage and current are 100% in phase.
>>1868373Is there any way to check if a device has a WiFi module in it? Besides opening it up and looking closely at the circuitry. Are there any kind of detectors?
>>1874415Yes, the angle is zero. Both power and energy are scalars. If you want the direction of energy flow you need an additional spatial reference to get a vector, e.g. that of the power density. When you reverse the polarity, the direction of flow is not affected because E x H remains the same.
>>1874421>are there any kind of detectorsYes. Now if you want help just give us device name
>>1874415Low IQ post.
>>1874426It's a noname chinese kvm switch. I'm kind of afraid of passing all my keystrokes through it, hence the question.
>>1874474The tool you require is called a frequency counter or EMF meter. Wifi signals fall between 2.4 & 5 GHz.
>>1874474You can put it in a metal box.
>>1874477Do you think it will detect searching for WiFi APs? I'm trying to detect the "receiver" not the access point.>>1874485Yes, that was my initial plan, but I read that the box shouldn't have holes that are larger than 3mm so the holes for the wires might ruin it.Anyways, I'll just try to setup a public WiFi next to the KVM and look at the logs.
>>1874487Uh not really. If you put in a metal box with holes the signal will be attenuated a lot. If you put in a perfect box then no signal will come out.
>>1874487The wireless module is a transceiver as well as the AP/router, and it operates on the same frequency. Yes, you will be able to detect a wifi signal from either end, but you need a noise signature and DSP to differentiate from other devices signals, or a Faraday cage to isolate the suspect device. You want a logging/graphing feature on the frequency counter so you can detect signals over time.
I suspect a broken one of these is making my equipment glitch out since I'm reading 2 volts less than the spec sheet.This outputs AC, can I use my labs power supply that outputs DC to test the board that feeds off the AC transformer?If not how can I determine the fault without buying a replacement transformer?
>>1874522Is the transformer output rectified in the original circuit? Post spec sheet.
>>1874522yeah, the transformer probably feels into fool bridge rectifier anyway
>>1874474> I'm kind of afraid of passing all my keystrokes through it>literally connects to fucking PCs>worried about wifi modules inside
>>1874527>>1874532It's an electric organ, using the bench PSU gave me power but no sound, I'm guessing maybe the amp part wasnt rectified? I'm assuming the low voltages cause glitches like weird notes sounding when no input.
>>1874522Uh sure dude just clip the wires or something.>>1874560The picture shows that most stuff is rectified, but you clipped the part where it shows the amplifier. But it is most likely also rectified.Uh remember that guy who asked about how inverters send power to the grid? Well I actually put my noggings to work and read some books. It's related to the phase diference (Voltage phase diference!) between the grid and the internal voltage at the inverter. Pic is a basic proof. Apparently it is a babbys first intro to power grid dynamics and works for any AC source.
>>1874564>>1874560Also if you suspect the transformer is broken (it almost never is) just disconnect it from the device, and measure the secondary voltages while connected to the wall. You won't get shocked if you only play with the secondary coil.>>1874564To clarify, in sync machines the theta used here is called "power angle" (not power factor!). It is both the internal voltage phase diference and the angle of the rotor with the resultant magnetic field. Cool. I'm just happy that my brain hasn't atrophied during covid, I'll stop blog posting now
>>1874560>>1874564>>1874567I'm suspecing amp wasn't rectified since it worked fine but no sound. Anyway, discoveries were made, my multimeter is whack and measures 1-2v off all mesurements. I borrowed one and made sure.Spec sheet mentions CN11 pin1-2 = 26±4Vac but I'm getting straight 5Vdc, so that can't be right.What on earth is a VOK Generator, I'm not finding any info online
>>1874576dude basic troubleshooting here. You said you suspect the problem is the transformer right? Measure the transformer. It says there they should be 16v and 13v. (so if you measure red to red you'll get 32v). And the amplifier IS rectified,
>>1874581Yeah, sorry I maybe wasn't clear, been there done that, I suspected the transformer because my multimeter was reading off, now I have a new one I can accuratly say the transformer is in spec.I've been troubleshooting following the spec sheet and the only point I can find that doesn't light up is the pins I mention that are supposed to carry 26Vac but carry 5Vdc (as far as I can tell), so whatever the VOK generator is it doesn't seem like it's working.
>>1874584Unless you can spot something obvious you should follow the trail then.>wall->transformer->diode rectifiers->regulators->other shitThe diode rectfier is the big diagonal stuff with an arrow. The regulators are IC2,4 and 6. I'll repeat, what you are showing is NOT an amplifier output. It's just a bunch of regulators and some other shit.
>>1874576The presence of the VOK signal tells you that the voltage is ok, hence the name.
>>1874601>VOK signalMind blown>>1874588Yeah, I'm aware, I wasn't trying to troubleshoot the amp, it's working.I'm trying to work my way backwards from the CPU & Sound generator board, the one mentioned next to the CN11 connector.Following instructions from the troubleshooting section of the Service Manual I've spotted that the VOK output on CN11 and GND should read 26Vac but I'm getting 5Vdc so I'm suspecting the BC550's are toast. Does this more or less make sense or am I barking up the wrong tree?I suspect I may be wrong since it strikes me as weird the device would power on and work with the ocasional glitch with a reading so off.
>>1874424>Both power and energy are scalarsScalars can be negative as well as positive, I'd say treating that as a 180° phase difference is at least a tiny bit sensible.You can also express power in the complex plane, just as is done in order to measure/calculate power factor of an arbitrary phase difference. Though perhaps this complex power should be treated as more distinct a concept.>>1874576>fuse after the Y capsprobably not a big deal but ok>transformer across live and ground not live and neutralWhaAT thE FuCk
>>1874607>should read 26Vac but I'm getting 5Vdc so I'm suspecting the BC550's are toasteither the manual is wrong, or you're confused. if you trace the VOK signal back, it comes from a transistor that's powered between 5V and ground. so, that transistor can only put out DC voltages between 0 and 5V. i suspect the confusion comes from what VOK does: it presumably puts out 5V when 26Vac (or anything close to that) is present from the transformer.
>>1874697>that transistor can only put out DC voltages between 0 and 5VCall me stupid, but don't those two transistors make an oscillator?
>>1874702>Call me stupid, but don't those two transistors make an oscillator?you're stupid! they are 2 inverters in series, that latch ON when AC is present.
>>1874703>they are 2 inverters in series, that latch ON when AC is presentOh yes, that makes more sense. Couldn't have that high of an amplitude anyhow. But I don't really get the point of it, as it's latching on AC from the ±13VAC transformer winding, while it's being powered from both the +12V and +5V rails, which are both derived from that winding. I guess it's to check that the +12V and +5V regulators are working? If the +5V regulator isn't outputting 5V then the output won't show 5V but rather ~0.7V, but if the +12V regulator isn't working then the output will still be 5V. If the winding isn't working, then the whole thing will be 0V. Shoulda used an AND gate instead of a latch, what's the point of it even latching? The initial "latch" command comes from the transformer winding, which can't reasonably go off afterwards if the +12V and +5V rails that power the latch are still working.
>>1874709the 5V regulator looks pretty complicated. it may have some inherent delay, and they dont want things to start up before that 5V is rock solid.
hey I have a question. I am using an eeprom that has a spi interface. I am a little confused about the clock of the spi. Would it make sense that different operations you use the eeprom for would have different clock speeds, for example fast read and read have different max clock speeds. Or should they all have the same clock speed and I’m misunderstanding what it means.
>>1874702>those two transistors make an oscillator?That circuit would normally be called a Schmitt trigger.
>>1874357Triangle wave anon, how did you learn about musical circuits and phase and Fourier and stuff?