Rewind back to 2012 or whenever

Is it like this for everybody trying to prototype? do companies knowingly ship broken components to hobbiests knowing they wont (or can't) complain?
What do "professional" electrical engineers do? do they just buy old-ass VCRs and shit and spend more than half their time un-soldering stuff they know has worked in the past?
Do they spend a 500% premium for components they know will work?
Is there some kind of black market for working electronic components?
Do these companies selling this garbage only ship working components to businesses who buy them?

thats what you get for buying from C H I N A

ive never had this problem and i buy from ebay.

Mechanical parts always have a higher failure rate because well, they're mechanical. However, most other components fail because your circuits are probably designed like shit and overwhelm the component specifications/ constraints. Variance in components is a given, it's a difficult process to manufacture the correct material compositions to maintain high precision, hence the premiums.

Here's your solution: RTFD for the components you're using.

Can this be a general electrical engineering thread?

I've got some ideas for digital circuits, but I don't know how to make them. That is to say, I know how I need to connect my buffers, decoders, muxes, and busses on paper, but I don't know how to actually construct the circuit. I have questions like "how do I know which resistor to use in my pull down branch?" or "how many things can I connect to VCC all at once?". Does anyone have a recommendation where I can learn this stuff quickly?

Get an FPGA and learn VHDL (or Verilog, not a fan). You can design and test any digital circuit entirely with code from the base components.

or if you're hell bent on doing it with chips like the 7400 series, a test bench like this has all the extra test tools to make it easier to build and debug (this is what we used when I first learned digital logic).

ARE YOU KIDDING ME?
YOU'RE A FUCKING WHITE MALE!

No, seriously, why the fuck aren't you measuring all of your components before you try to use them anyways?
I guess that's alright if you've never taken a Circuits class/lab in community college, heh

I've used FPGAs before, but for my current circuits, I'm at the stage where I want to breadboard them before potentially designing a PCB.


Thanks! Something like that should do the trick.

I do, it's just that everything has a ~80% failure rate upon measuring them.

Calm down famalam, it's k.

Honestly, I don't have so much trouble with components. Desolder old japanese made shit from home electronics from like the 90's , but shit, if I don't ground out religiously,
ZAP

Never had those issues with digikey. Nothing but positive, consistent, timely results.

...

BTFO

>>>Holla Forums

...are we sure it's not just that you have components that have 20% tolerance?

...

Try Jameco, or just buy shit from China directly. Whatever. I think you have cursed fingers. I never have problems with components, but bad schematics. Fuck me for thinking that people who take the time to draw a schematic actually bothered to calculate the proper values for the inductors and caps in the fucking thing.

Just buy a breadboard and plug things in, dude. That's how you learn. Don't buy an FPGA like the other guy said, I don't know what the fuck he's smoking

just make your own components instead of buying premade like a pleb

problem solved

Oh yeah and check your frequencies too, inductors and capacitors change with frequency. duh

Seems more like the test is the problem.
How are you testing them, and with what ?

Make a schematic in the CAD software of their choice, complete with a full Bill of Materials (BOM) for the project. Then they order the parts from the supplier of their choice, for personal projects that's usually going to be digi-key, mouser, or jameco; for professional projects that's going to be whoever the guys in charge of supply chain struck a deal with.

Breadboards are nice, but for a lot of modern electronics you have to deal with surface mount out the ass. Prototype boards are built using CAD software to make a layout, and then having the pattern etched by a professional outlet. This usually takes a few weeks depending on the size of your order, larger orders will get higher priority. You can also DIY it and chemically etch copper boards yourself.

Then after it's been prototyped and tested and you know it works, you push it off to full production where they get a factory in China to shit out 10,000 units a week.

How old are you?

I've always bought a fuck-ton of electronics parts from China and local stores and never something failed at me. You're probably somebody with really bad luck.

Go back to Holla Forums.

This, what are capacitive and inductive reactances?
Do you even imaginary numbers, faggot?

How senpai?

At the right frequency a wire that doesn't even connect to anything will act as either a capacitor or an inductor, depending on it's length and material impedance to the passage of EM waves (not to be confused with resistance).

If you look at circuit boards sometimes you'll see a little trace of copper that doesn't go anywhere. That's usually a capacitor or an inductor with a very small strange value chosen specifically for the operating frequency of the signal at that part of the board.