Short Circuits Episode 1
SavageCircuits
Posts: 267
Check out Short Circuits, a new engineering humor series of videos from Savage Circuits. Available in HD where available! :cool:
Comments
I wish I had videos of some of the things I tried as a kid when I first started playing with electronics! (Went up in smoke...)
When I was older, I got a job as an electronic technician and worked with electrical engineers. I thought these guys were really going to show me some things... Well they had the same problems I did. They would build a prototype, power it up, then there would be a flash, smoke, and an embarrassed EE!
Then I've often heard of electronic prototypes which work perfectly well when they are a rats nest of wiring. But when the design is cleaned up and all the wires neatly tie-wrapped, etc., it does not work!
I recently had a problem like that. I connected a keyboard using a nice neat ribbon cable. It would not work! I separated the wires so it looked like a rats nest, then it worked perfect!
The problem was the wires running next to each other were acting as capacitors. And the microcontroller scanning the keyboard was running so fast, the wires did not have time to switch from + to -. A line which was set to + would be switched to -, but when the next instruction came along, the line was still in the + range. This problem is called parasitic capacitance...
http://en.wikipedia.org/wiki/Parasitic_capacitance
I've only had one such "exploding" case:
I've built a power supply in a cardboard box. It was the classic analog "evil scientist lab" type, with pots, meters, incedecent indicator lights, etc.
I hooked it up to an LED, and (to my delight) the LED caught fire and exploded after a short period of time. I was so entertained watching the LED, that I failed to realize that my box was smoking. After the LED was destoyed, I noticed that there was sparks and flashes of light coming from the inside of the box, allong with plenty of smoke. I unplugged it quickly and hoped that the box didn't catch on fire. I turned out safe, but now I don't use anything but metal for power supply enclosures. :-)
Without the required explanatory lead-in next time, these will be short, witty, and cool. Engineers just love to change things.
OBC
1/2 Air + 1/2 Water = 2/2 = 1 ... Full!! :smilewinkgrin:
Great job Chris!!! Keep up the excellent work!!
One view is that all cows are black and white.
Some would say all the cows IN THIS FIELD are black and white.
And a mathematician would say that all the cows IN THIS FIELD have at least one black and white side.
Details.... details..... details....................
Corporal Punishment reporting to General Discussion - over and out.