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Prev thread at bump limit. I don't often hangout here, forgive me if this isn't perfect.
Prev thread: >>2794153

>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.
Read the datasheet.

>OP source:
https://github.com/74HC14/ohmOP

>Comprehensive list of electronics resources:
https://github.com/kitspace/awesome-electronics

>Project ideas:
https://hackaday.io
https://instructables.com/tag/type-id/category-technology/
https://adafruit.com
https://makezine.com/category/electronics/

>Books:
https://libgen.rs/

>Principles (by increasing skill level):
Mims III, Getting Started in Electronics
Geier, How to Diagnose & Fix Everything Electronic
Kybett & Boysen, All New Electronics Self-Teaching Guide
Scherz & Monk, Practical Electronics for Inventors (arguably has minor issues with mains grounding)
Horowitz and Hill, The Art of Electronics

>Recommended software tools:
KiCAD 6+
Circuitmaker
Logisim Evolution

>Recommended Components/equipment:
Octopart
LCSC
eBay/AliExpress sellers, for component assortments/sample kits (caveat emptor)
Local independent electronics distributors
ladyada.net/library/procure/hobbyist.html

>Most relevant YouTube channels:
EEVblog
W2AEW
Moritz Klein

>microcontroller specific problems?
>>>/diy/mcg
>I have junk, what do?
Shitcan it
>consumer product support or PC building?
>>>/g/
>household/premises wiring?
More rules-driven than engineering, try /qtddtot/ or sparky general first
>antigravity and/or overunity?
Go away
>>
Is there a reason the thread copypasta doesn't recommend digikey/mouser/arrow/avnet for partprocurement? Generally a higher price point for the same shit? I'm a bit ignorant to the landscape outside the above, mostly industry experience buying stuff and shipping it fast on company/customer dollar.
>>
I need an amplifier circuit that can boost a very small DC signal to around 10-30V while keeping it's shape. The DC signal might be positive or negative and I want the output to also have those two halves. How could that be achieved?
I've made one before for square wave but that had a fixed signal shape and I didn't need it to go in reverse polarity. This one is new for me.
>>
>>2799799
A comparator does exactly this: compares two voltages (here input and ground) and outputs positive voltage for pos input and vice versa.
>>
>>2799808
Would it work with sine waves as well?
>>
>>2799810
Instrumental amplifiers keeping the shape
>>
>>2799811
Alright, so the application in question is electrochemical analysis. I've got an equipment that has precise control over voltage and current and can do all sorts of voltammetry and pulse sequences but it can only go so high in terms of voltage. I'd like to amplify that while keeping the shape and accuracy of the signal so what'd measure off of it will be an accurate representation of the chemical processes happening in the electrodes.
From what I can see at a glance from wikipedia it seems an instrumental amplifier would work for that end and the schematics seem simple enough for me to try building one for experimentation.
With that background on the intended use, can you think of any better fit for this purpose?
>>
>>2799794
They're still listed among other in the last link. They'd be worth recommending specifically too because how can you not recommend building up orders to get free delivery and have stockpiles of basic components because you added 20 bridge rectifiers and 100 1n4001 etc. that one time.
>>
>>2799790
>I don't often hangout here, forgive me if this isn't perfect
Did you read the part at the bottom of the OP that you avoided copy-pasting that said "bake at page 10, post in old thread"???
>>
>>2799794
They're included in Octopart. Octopart is an aggregator for the big vendors like Digi-Key and Mouser, and a lot of smaller vendors as well. They also generally have a better parametric search function, allowing you to set a minimum value for the maximum input voltage, for example. Though can get a bit strange when different vendors have different data formats.

The reason I included LCSC separately is because Octopart doesn't scrape all the unique parts on LCSC, it only shows the western parts that LCSC shares with the other vendors. LCSC has a lot of interesting cromulent ICs that you can't get anywhere else, like linear high voltage LED drivers, TP4056s, along with chinky copies of western parts that go under different names, like the GD32F103. Their passives and jellybeans are also generally cheaper, though there is no free shipping threshold. They ship worldwide regardless of location, so if like me you're in a country where Farnell and RS are the only vendors available, you can see why it would be worth not paying $10 each for one of two available SMA connectors. Keep in mind the shipping thresholds though, more expensive part prices might be offset by free shipping.

In no way am I recommending using AliExpress or whatever as a replacement for proper vendors for anything but the most bog-standard parts. Or maybe surplus parts for a game console or laptop. I got out-of-spec TL072s once, and IR2148s that were dead on arrival. Stick to the proper vendors for things that matter.
>>
>>2799818
30V is kinda high for electrochem, but sure. An instrumentation amplifier is the sort of thing you want for amplifying a weak signal without incurring offset, but such an amplifier can only provide so much current. Electrochemistry can easily get over 1A, which at 30V is 30W. That's a lot of power for a linear precision amplifier to dissipate. For that kind of power, what you'd end up doing is designing a DC-capable audio-style amplifier stage that runs off a split-rail supply (e.g. ±32V), and using the instrumentation amplifier (or similar op-amp circuit) in a feedback loop in order to make the output perfectly follow the input. It's also an option to go for a switching solution, though with a bipolar supply that can sink and source current I'd advise against it unless you really need high power.

Also the feedback loop of the existing equipment may interfere with this circuit. When it sets 0.1A through an electrochemical cell, it's constantly changing its voltage while measuring current in order to keep it at 0.1A. If it won't measure anything above 0.5A, then outputting 1A wouldn't work, even if your amplifier could take it. You may need to augment the measurement ability of the existing equipment, or even use your own circuit to set the voltage and current independently with a CC/CV amplifier combination.

I'd write down some specs. Maximum voltage, maximum current, accuracy of voltage, accuracy of current, that sort of thing.
>>
>>2799850
Max voltage is 30V. It is that high so I can dabble in electrochemical synthesis if I want, might happen and I want to future proof this project. Max current is around 100mA, that should be plenty. Commercial electrochemical reactors have an accuracy of around 0.01mV and 0.1mA, so that's what I'm sort of aiming for.
Sometimes in those processes the voltage isn't the variable controlled, but instead the current. So you set it to something like 4mA per mole and the device gives it as much voltage as it needs to hold that current. My little potentiometer can do that, but at much lower power, I'm not sure how to amplify that. It can reach the currents I need but the problem comes when I start doing synthesis at larger than analytical scales and need higher voltages to maintain that current.
>>
>>2799374
I want to go with relays instead of the mux IC now. Just because I can. It has more Sovl

I have a bunch of old very sovlful looking transparent relays. But they have such an usual footprint that I won't be able to assemble more of those PCBs - 5 pcs is the minimal quanitity

Please recommend me some common, easy to get (ideally on chinkexpress) DPDT relay.
Only requirement is it should have a nice lout *klack* and be PCB mountable.
(EXTRA DOUBLE TRIPLE) bonus point if it is transparent

Also can I use an NGATE MOSFET to switch them? Most of the time I see BJT trannies being used.
>>
>>2800046
Almost all microwave ovens have two of these, they’re as common as… microwave ovens in dumpsters. I haven’t bought a relay in years.
You can de-case them and make little acrylic boxes for them and light them with leds like those tube amps. They will work fine without the case, I have bigger relays that never had cases.
You can go full “clack” if you buy a relay that electricians call a “contactor” for some hillbilly reason.
>>
>>2799940
Get an opa541, it’s 10 amps.
It costs like $10 too, so I don’t know why you’d ever need much else for that kind of thing.
>>
>>2800062
Oh, and I forgot to mention those lazy fuckers use this shit in missiles to control servos and whatnot instead of designing something with 3055’s.
Although, at $10, I can’t blame thme.
>>
>>2800046
recc me some klickity klack relays
>>
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>>2800055
I found those HK19F on ali. Dirt cheap shit, I hope this magically doesn't transate to the longevity...
Guess I'll dremel the cap of and glue a plexi plate or something on
>>
>>2800084
China makes better relays because they don’t give a fuck about environmental laws. U.S. probably can’t even make a mercury wetted contact. China can.
>>
>>2800062
>$10
In my country that turns into 100, plus importation and taxes and it's almost 300. Any cheaper option? Can I make one with discrete components or would that be too complex?
>>
Just want to put this out there. Thank you for giving better advice, by whatever margin, than /g/ on actual technological discussion. Threads like this >>>/g/100495470 are a regular occurrence there.
>>
>>2800106
You can absolutely make a good op amp with discrete components, and doing so with even the cheapest transistors tends to really boost the current available at the output.
>>
>>2799940
>Max voltage is 30V. It is that high so I can dabble in electrochemical synthesis if I want
Aren't electrochemical potentials like no greater than 5V differential? Maybe if you get some really concentrated reagents or do molten salt stuff the nernst equation can push them past 8V but idk man. 30V sounds overkill unless you're dumping 3/4 of that voltage across the series resistance of your system. Running at an overly high voltage in that kind of situation sounds like a recipe for unwanted side reactions, especially dissolving your "inert" anode. Though if you have a glassy-carbon anode I'll retract my last statement.
>Max current is around 100mA
100mA at 1V with a 31V power input means 3W of power dissipation worst case, you'll either want a power package monolithic amplifier or a BJT output stage. Combining a monolithic audio amplifier (LM1875, LM3876, etc.) with a jellybean op-amp is an idea, see EEVblog's vid on combining opamps.

>I'm not sure how to amplify that.
Does your existing piece of equipment go up to 100mA? If not, you could just amplify the current output by converting it to a voltage and back with some op-amps and resistors, or even modify the existing current sense resistor. But then you'd have the issue where you have to use a conversion factor on the current-per-mole.
It's a pain, but you may want to try to modify the firmware of your existing equipment, or build an entirely new setup that has its own display and control mechanism.

>>2800046
I was using Panasonic DW2 and JW2 relays recently, the DW2 is pretty small and I think even perfboard compatible.
For larger but transparent ones, try these:
https://www.jaycar.com.au/medias/sys_master/images/images/10260934688798/SY4008-dataSheetMain.pdf

>>2800106
Y-you're not from Brazil, are you? Go to sound-au.com for some discrete op-amp designs.

>>2800116
That's a bait thread. At least compare this to their gnu/linux general, but most of their threads are too fast to get good advice anyhow.
>>
>>2800153
I plan to try this with TIP31 and TIP32, maybe KSC1845/KSA992 too or op amp or both. For first ever I'll be content unless it shorts supply and lights the speakers on fire. That wouldn't even be so bad I can test with the speakers picked up from by trash collection area.
>>
>>2800157
>voltage
Yeah, but I also want to be able to do electrosynthesis so I want something beefier.
>brazil
Maybe...
>>
>>2800046
>Also can I use an NGATE MOSFET to switch them?
Yes but there's no real benefit to using a more sensitive MOSFET when some 2n3904 saturation goes brrr on any logic level
>>
>>2800172
There are a few benefits to using a FET for switching a relay:
>lower power dissipation - means potentially more reliable, and can be in a smaller package
>doesn't need a series resistor if you use a logic FET instead of a power FET
>less load on the signal source - could be a problem with a dozen relays
>insulating channel between the channel and gate means less likely to fry your MCU in event of failure
Though if you're sticking to THT parts your selections are limited. And by that I mean you have literally one common logic FET, the 2N7000, and it's a bit shit. The resistor point is also moot if you use a logic transistor (i.e. a transistor with resistors built in) or even a logic transistor array like the ULN2003. It's a darlington array so not only do you not need resistors, but you don't need to worry about input current either. Plus it comes with freewheel diodes built-in. It (as well as similar arrays) are the obvious parts to use for relay driving, as they minimise the required components. There are MOSFET versions of the ULN2003N that might beat it for current capability and thermal characteristics, but they're less common, and probably not found in DIP packages.

The main downside of using FET-based relay drivers is ESD sensitivity, but when they're soldered into a circuit with a CMOS output driving their input, this really isn't a concern. FETs might be more prone to damage by inductive spikes than are BJTs, but either way you should be using a freewheel diode.
>>
I bought a bunch of HF electronics, but guess what

they are all stolen by some faux angel.

I regrette moi, but I want to just buy more of them.

I'm still wondering if you girls will just disconnect everything 'once it works', just cuz the voices tell you.

I'm really wondering why DigiKey is so expensive. Mouser doesn't seem to have anything. The best way to get parts is still to buy the completed product, and break it into pieces.

I have some "lifepo4" but they're DED. I don't know, phosphate explodes you know?
But maybe the iron mountain... the lithium the lithium...

I think it sucks. Whatever I do.

Anyway, I could powder out of one of these cells, and the result would be -- that I spread them way above the house... like at 800 meters?... The lithium might be 'detoxification' for all the mountains, but I'm not sure, I'm not sure..
>>
>>2800046
>sound-au.com

where's the app?

where's the "I don't care where I shop" app?
>>
>>2800097
>mercury wetted contact
So I should NOT open them, I guess??
>>
>>2800116
Regardless of userbase, imageboards tend to become shit as soon as they get faster. Add the masses of bots and retarded underage normalfags and you have the cesspit that is current /g/.
hopefully /diy/ will always stay /comfy/
>>
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aaaah fucking retard chinks and their pozzed bogshit website
>>
>>2800238
take your meds

>>2800290
That's why i'm in favour of a "tree chan", where the faster board categories just get split into smaller slower boards. A general thread that's been sufficiently fast for enough time becomes a new board itself. Zoom out and you see the entire hierarchical tree. The mascot would be a leprechaun.
>>
>>2800307
weirdly I can still log in over the browser from my phone and just placed an order this way.
Wondering if I got banned because I opened 2 disputes in the last 2 months or so getting scammed over empty epoxy blocks larping as ICs
That would be really invigorating since I've been using that bogshit scamsite for ~4 years now and propably have over 1k orders
>>
why do they always use pnp trannies to switch relays?
can I also use a mosfet?
>>
Anon, I need a project for my final year humiliation ritual. What do?
>>
File: DSC_2511.jpg (3.36 MB, 4000x3000)
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Doesn't look good, does it?
>>
BS170 N-CHANNEL
>>
>>2800322
you generally want at least one side of your large electromechanicals to be tied to ground
picrel is floating
>>
>>2800338
so PNP?
>>
>>2800338
Anon, can you tell me what's going on with the output on the tranny? >>2800336
>>
>>2800322
1) It's NPN, not PNP in your picture.
2) "BC109": obviously that's an old circuit or a circuit drawn by an old person. Back then the commonly available MOSFET needed 10V to switch on completely. TTL had less then 5V, so bipolar transitors were used.
3) Yes, you can!
>>
>>2800342
I also want to use it to switch a 1khz pwm signal.
But it doesn't really work. >>2800336
It says 10ns turn on time in the datasheet https://www.farnell.com/datasheets/694801.pdf
>>
>>2800344
The osci output is very jittery and inconsistent
it has those weird spikes
>>
>>2800338
>you generally want at least one side of your large electromechanicals to be tied to ground

Why? And when you say "at least one side", are there situations where you ground both sides?
>>
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>>2800344
BC33 good 'nuff
>>
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Fried another tarduino plussing in my laptop while osci/psu was connected
>>
>>2800378
>Fried another tarduino
How?
>>
>>2799790
Nakasashi sex with all the JK assembling the PCB
>>
>learning2electronics
>go absolutely insane trying to fix a circuit made of opamps
>output slams to rail regardless
>give up
>last opamp on the breadboard
>wait
>make a simple buffer
>1kHz sine clipped
>swap opamp
>it werks
I may be retarded,
>>
>>2800380
Ground loop or whats that called
>>
So how hard is it to read from an analog sensor and control a BLE device according to some function of sensor data with an ESP32? I have very little embedded experience, but know how to program in python and C#.
>>
>>2800410
Depending on how quick your uptake, moderately. Can use Arduino, Reading ADC is hello world level exercise. Connecting BLE likely is boilerplate you can copy from examples, after that the controlling part difficulty should depend on the device.
>>
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Beginner here trying to get a stepper motor going, any idea why I'm not getting a proper read trying to set the current limiter on an A4988? I've got everything hooked up properly, sleep and reset is bridged, the motor hasn't been hooked up once so I don't think I've fried it, but trying to use a screwdriver just shows up as ~0.3V on the multimeter, and as I spin the screw it stays there until it randomly drops to 0 before another turn brings it back to 0.3. I just don't know what to try anymore.
>>
>>2800384
1985:
> is it live, or is it memorex?
2024:
> am I retarded, or is it zheng scamming me?
>>
>>2800421
I can’t tell what your mulitmeter is set to, AC or DC volts, but I think the stepper motor controller is going to try and give out pulses, so it won’t necessarily read correctly on DC or AC, although AC is more likely to be closer.
>>
>>2800468
>zheng scamming me
To be fair my current PDIP stock comes from Digikey so if the opamp was shot it was probably on me.
>>
Best brands/stores for high voltage DC power supplies (around 300V 10A) Google just brings up aliexpress crap.

Ideally also has some sort of remote control ability.
>>
>>2800584
Meant to include a question mark somewhere in there lol
>>
>>2800584
You realize that’s gonna be more than double what you can pull out of a standard north american outlet eh?
>>
>>2800590
Gotcha, thanks.

If you think I don't know what I'm doing, you'd be right.
>>
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>>2800584
>Best brands/stores for high voltage DC power

if you use digikey's parametric search, you'll find plenty of contenders
unfortunately, high power comes at high prices
very high, cheech and chong levels of high
>>
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>>2800584
33 9V batteries in series
>>
>>2800584
Rectified 220-240V mains is in the realm of 310-340VDC, you'll be able to pull 7A continuously from that without tripping a breaker, higher for shorter periods if you keep mind of your breaker's trip time curve. Assuming you have a lot of bulk of output filter capacitance. If this kind of voltage is fine for you, it's going to be at least an order of magnitude cheaper than a switching supply capable of the same power. Though the output isn't isolated but solidly mains referenced, so neither the positive nor negative output will be safe to touch. And tying an end to ground would trip your RCD. Maybe you can isolate it by buying a (2nd hand) 2400VA isolation transformer, though that would probably double the cost.

A rough calculation:
>I = C*dV/dt
>C = I / (∆V * f)
>f = 120Hz (halve this for a single-diode rectifier)
>∆V = 10V
>I = 10A
>C = 8mF (double this for a single-diode rectifier)

American houses have some 240V outlets IIRC, be it for an oven or electric water heater or whatever. Microwaves maybe.

What's it for?
>>
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>>2800374
What does it mean by that?
Now I get the same jittering again
>>
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Guess its the breadboard
>>
>>2800675
?????????
>>
any issues with this circuit?
the trannies are controlled by a tarduino
>>
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hurrdurr forgot to attach the picture >>2800701
>>
>>2800702
looks fine to me
though using one of those 10-step telephone contactors would be cooler
>>
>>2799790
got myself a 450V shock from a tube amp last night. would not recommend
>>
>>2800707
I'm using the cheapest chink relays I could find at 50ct a piece https://youtu.be/WVRW3949kdA
>>
>>2800665
Pls help. Why does it do this?
>>
>>2800748
>Why does it do this?

we might hazard a guess if we knew what ''it'' is
dont be mysterious: show schematic, show what place you're probing, note all DC voltages
anyway, wild guess is that you forgot the diode across the relay and you're getting large negative kickback voltages
>>
>>2800775
No, that's the PWM brightness control for the LCD backlight. The BC337 has a base resistor of around 5.8k, driven by an arduino.
No clue if I should have PWM anywhere near an analog audio path in the first place ...
Wont have access to the shit for next week anyways. The relays and the other shit should have arrived by then (hopefully).
Next trouble is I'll have to wrap my head around the software stuff, especially this SPI fuckery and get the LCD and digital pots (for baxandall eq) which both use SPI to somehow play along as the tarduino only has one SPI interface as far as I'm aware.
>>
>>2800808
>PWM anywhere near an analog audio path
Near is a loose term but I'd put all digital things on separate PCB in the final version.
>SPI fuckery and get the LCD and digital pots (for baxandall eq) which both use SPI to somehow play along
Shouln't be a problem, SPI can have multiple slave devices.
>>
Does anyone here have experience with working on synths? Someone is offering an untested Yamaha DX-7 near me for $150; I was thinking of making a lowball offer and seeing if they take it. The thing is opened in the pictures, comparing it to online photos everything seems to be there. If I decide to go through with the purchase, what are some common issues that these have that I should take a look at? I know about the battery requiring replacement, and everything else I see online seems like the standard "sliders and knobs need deoxit" type of issues.
>>
>>2800808
LEDs take some time to turn on and off. You’re basically using an LED like a pull-up resistor across its own capacitance, and it’s effective resistance gets really high at low voltages. If the backlight itself looks fine, who cares what the waveform looks like. If not, try lowering the frequency.

>>2800831
>SPI can have multiple slave devices
Yeah but most MCUs can’t have multiple hardware SS/CS lines for some reason. Gotta either use seperate SPI pins or not bang that CS line.

>>2800943
If boards aren’t cracked or have fried chips on them, it’s probably fine. Even cracked plastic you can replace with a 3D printer.
>>
>>2800943
I didn’t know anything about synthesizers, but reading up on the DX7 for a few hours… it’s is an amazing and iconic piece of technology from the early 80s… almost an alien technology. It’s practically an arbitrary waveform generator.
I’d love to have one, broken or no, just to mess around with.
>>
>>2800990
>it’s probably fine

a 40yo piece of electronic gear used by degenerate musicians is likely gonna be as healthy as an 80yo junkie hooker
like mom
>>
>>2801019
I meant more that it’s probably repairable for <$30 and a half dozen hours.
>>
>>2800055
Checked. If I had to guess the hillbilly reason is because they make and break contact at multiple points simultaneously. There’s probably relays like that but most I’ve seen are a one channel deal.

>>2800082
I’m seconding the definite purpose contactors. Not the cheapest but definitely the most clack for your stack?
Usually 120V coil but I’ve seen 24VAC.

>>2800421
Go watch paulmcwhorters stepper vid or something. A picture of your actual breadboard would have been more helpful to figure out how you wired it wrong. It doesn’t go with just plus and minus like a regular motor. Steppers take plus,minus and a control wire with a square wave to tell it what to do.

>>2800584
This is DIY and I want pics of a series-parallel transformer configuration and the biggest diodes you have ( or a bunch of small ones parallelled) Preferably with all the components zip tied to a 2x4 with the photo labeled “circuitboard”.

>>2800656
This will work too but the xtra xfmrs will look cool and isolate from mains.
>>
>>2800709
It bites pretty good but unfortunately I've been bit too often and got used to it...not good. Taught me to be more careful, can't do electronics as a corpse. What did you do?
>>
>>2800324
This might give you some ideas:
>https://github.com/74HC14/ohmOP/blob/main/ProjectCategories.md
If you want something specific, maybe a metal detector with phase discrimination? I'd like to make a large format one myself, the size of a pallet that would be wheeled around. The larger the coils are, the deeper they should be able to detect. Maybe you can even have an array of transmit and receive coils to increase the effective depth, might be a good use of some magnetics simulating software. Huygens Optics has a neat video on how metal detectors work.

If you want something more specific, please elaborate.
>>
>cnc-ing a pcb
>notice that Y axis stopped working, the screw that holds the screw rod & the stepper motor loosened and it is no longer moving on Y axis
>the damage is not that bad, I noticed it early
>turn CNC sideways to screw things back
>3 out of 4 screws that holds X stepper motor falls off
Fuck, did vibrations loosened them or what? It is amazing only 1 screw was holding X stepper motor
>>
>>2801179
Ghosts did it. The derelict-dead dread spring washers and the essence of threadlocking.
>>
>>2799790
recently bought a 0-30V, 0-3A dual output power supply that can be wired up series or parallel. i was thinking, how badly would 60V DC shock me if i were to touch it?
>>
I bought around 20 TDA1521 stereo amp chips just because they are selling for peanuts and now I don't know what to do with it.
Thought about buying PCBs and selling them as DIY amp kits.
Any experiences selling your own DIY kits? Is there any demand for something like this?
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>>2801237
Probably fine as long as you don't have a wound where you touch it. Or try to lick it
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Heya fellas.
Is there a simple way to remove any epoxy or glue that's been used to hold down a CPU?
I'm wanting to resolder in a new CPU in my laptop but on my first attempt I learned that the chip is glued to the board at the corners, making desoldering a huge pain in the neck.
Anyone got experience and wisdom to share? Thanks.
Pic related; the result of my first attempt.
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>>2801255
1. Heat the epoxy with a shitty iron and scrape it up with a toothpick, or use a little acetone and let it sit.
2. You don't need flux to remove chips.
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>>2801255
a solvent + toothbrush. i would start with 91-99% IPA and see if that dissolves it. if not move on to other things. keep in mind that harder solvents like acetone can dissolve plastics.
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>>2801240
Just do it (yourself). Amplifiers are common DIY kit though, just getting noticed might be difficult without having something special(optional) or aggressive ads on Amazon or such. Just speculating though, I haven't sold anything I've made or made anything I'd presume to sell yet.

If they don't sell you'll still have 20 TDA1521 for something else.
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>>2801280
It won't, it's a goddamn worksite to remove. Desoldering four op amps from junk Creative 2.1 computer speakers took me something like an hour or pliers, heat from soldering iron, liberally applying craft brew PRF IPA(didn't really do much). Soaking in acetone beforehand sound worth trying, or maybe let it cook in oven so the epoxy is softened throughout before even attempting to remove it.
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Hello frens, sorry if this is a noob question but any good recommendations for books that provide electronic projects in order from very beginner to somewhat more advanced? I learned alot of the theory already but I wanna start getting practical experience (lots of it).

The projects that interest me the most I've looked up online and they're very intimidating and advanced, I don't trust myself with all of that until I learn how to do easier stuff
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>>2801292
I think I'll sell it with my digitally controlled eq that I'm currently working on. I created seperate eq and amp boards and want make them stackable like pcrel.
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>>2799790
Anywhere that can convert a circuit design into a formula for Kirchhoff or some other equation?
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>>2801303
doing your own homework and learning this stuff is not pointless anon, I know first year EE is not the most exciting, but you have to learn it to be able to move on to better stuff.
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lol, I either forgot to 0 Z at some point or added an extra 0

I should get some large sacrificial wood boards. All I had was 2 small pieces and I was not able to secure it properly. Some parts were flexing and the copper at those parts were not properly etched all the way through. I tried going a second time and ruined it
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>>2801323
These days we just send a tiktok of our homework to chatgpt and it does it for us ain't it cool to live in the future
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>>2799790
i love that image too much.
need an anime about cute anime girls who get shrunken in order to build pcbs
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>>2801383
Remember that manga series that taught some high school level stuff, including one of electricity? An anime like that would be really cool.
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>>2801385
>Remember that manga series that taught some high school level stuff
i do not, got link?
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>>2801396
Look for "the manga guide to [thing]". There's one on electricity, physics, biochem, all sorts of stuff.
It's an manga episode and then a small chapter elaborating on the topics, then another manga episode and so on and so fourth. Very cute but obviously no college level stuff.
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>>2801383
I crave the ham radio anime, the one I posted a synopsis for a year ago. Cute girls doing stupid shit innawoods and exploring the electromagnetic spectrum. What could be more comfy?
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>>2801430
What anime? I didn't knew it existed but not I need it.
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>>2801436
It doesn’t exist, that’s why I have to write it. I am bound to this destiny.
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>>2801475
Then do it before I eventually kill myself either willingly or by accident (most likely by accident).
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There used to be a "read this before you try anything" link for lithium ion batteries in the OP. Anyone know what IOM talking about?
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>early 20s
>"lets make X today!"
>make the circuit on a breadboard or etch using a permanent marker and copper clad
>hodgepodge a simple firmware for the MCU in the circuit, looks simple but actually quite clever and ingenious code
>by late night of the same day the project is done and working, there are bugs but it still works for the most part
>make a shitty enclosure out of cardboard
>sleep happy knowing I had fun and did fun stuff
>best of all, I never even considered not doing something because it may be too difficult or too much of a pain

>late 20s
>"I want to make X! Let me plan to make X in the next 2 months"
>do nothing the entire week
>weekend comes, make detailed plans about how I will make the project
>make a detailed schematic in kicad to eventually make a PCB out of (from a paid service ofcourse)
>spend a few weekends slowly working on a "robust" design
>get a PCB made, still have issues in it (usually abandon project at this point)
>start writing firmware
>firmware is "modular", very stable, probably could get MISRA compliance, yet is incredibly boring, tedious to write and appears to have no intelligence or ingenuity put into it (no clever or hacky code)
>fix all the bugs over a few weekends
>start working on the "mechanical design" in CAD
>spend a few weekends making the perfect, low cost of manufacturing enclosure out of 3D printed ABS or PLA or whatever
>order it from a service, get the part a week later
>project is done
>just kidding, I gave up on the design phase of the project because everything is "too hard" or "too expensive" or "I can't get it robust enough in the given timeframe"

Get a job they said. Your hobby will always remain your hobby they said.
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>>2801512
It got moved to elsewhere in the OP github. And by that I mean I forgot to add it anywhere and it's only in the "oldOP.txt" file. Here:
https://buster-spb.ru/files/SAFT/li-ion_user_manua.pdf
It's a bit of an odd document, as it specifically refers to Saft's own lithium cells, so it may be hard for noobs to apply it to other cells. Especially high current RC lipos, which will have quite different maximum current ratings for charge and discharge. It's probably worth looking for a better existing document to direct people to, or I could try writing one myself.

>>2801530
this hurts me
sometimes i can still get really into projects and spit them out quick
but man i burn out when it doesn't go well
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>>2801430
>>2801436
i found it: >>2476213
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>>2801530
i miss the days of cardboard enclosures too.



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