The unwritten laws and rules of Electronics

Nov 28, 2017 84 Replies

For something as large as a printer, it makes perfect sense.

I use more mini-Bs but the micro connector is a better connector electrically. 'C' makes more sense if you're powering something over USB or you need video speeds, or some such.

As *A* serial port. Which one, no one knows. I've been putting the MicroChip version of the USB/Serial chip on my boards as a debug aid. They don't get populated in production but it makes it easier for the software types.

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I think mini has pretty much been obsoleted

easier to use either a 6 pin header or a 3.5mm jack, and the ftdi cables

Everyone has piles of USB cables around but specialty cables get hard to find.

l.com:

The connector conspiracy has defeated you all. Five connectors, two gende rs each... An old Palm PDA with IRDA is more broadly compatible than those serial opti ons.

From my own experience:

A test pcb etch will come out perfectly.

The real pcb etch will be unusable.

Sylvia.

You have every known diode & transistor in the universe or an equivalent. And even more electrolytic capacitors. But that does not mean you have the capacitors you need right now.

NT

I did a 4-layer board (several iterations, in fact) to test a pulse generator output stage. The last try worked beautifully.

On the real 10-layer board, things are erratic, probably oscillation at a frequency my scope can't see. Or maybe probing kills the oscillation.

A surface-mount part, dropped from an arbitrary height, will land on the wrong side an average of six times. That is based on actual experience.

I need to develop some sort of backflip maneuver to improve this situation.

One of my production ladies can perfectly tiddly-wink parts to flip them, gets it right every time.

John Larkin Highland Technology, Inc lunatic fringe electronics

Dropped, say, 1000 times? And only six fall on the wrong side?

Practice makes perfect.

GH.

Obviously, once it lands on the right side, I solder it down.

John Larkin Highland Technology, Inc lunatic fringe electronics

That response does not answer the question. How many drops to get 6 to fall on wrong side? Are you evading the question?

Don't be a jerk. Nobody likes jerks.

John Larkin Highland Technology, Inc lunatic fringe electronics

Oh. I think I understand now. So, sometimes it takes you 12 tries to get to the point of soldering it down. Is that what you mean?

I won't if you won't. You start first.

Good for her. I normally only manage to squop or sub them :(

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That's not how Poisson distributions work. He said six because he means six, not twelve. That means there's approximately 12.246% chance it'll land the right side up on each drop.

Clifford Heath.

Sometimes I manage to completely disappear a part. Is there a tiddly-wink term for that?

If I need one, I'll snip a strip off a reel from stock, figuring I'll lose a couple one way or another.

John Larkin Highland Technology, Inc lunatic fringe electronics

Exactly five. :)

If the math is confusing, recall the title of this thread.

She probably puts butter on the bottom side.

I have sets of these for prototyping and test:

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