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Very Large Capacitors

Jimmymcjimthejim said:
Nice! I want to see some aftermath pictures of the poor screwdriver you toasted.:eg:
Click to expand...

The terminals of the cap look worse than the screwdriver does. Frankly it doesn't look too bad, just a dark deformed spot no larger than 2mm across.

The worst I've seen from shorting a cap was one time when I was attempting to fix a computer power supply. It was making a buzzing sort of noise that was identical to that of a wire just barely brushing against the fan as it spun. I had had this problem before so I did what I had done before. I knelt down to the computer and poked a screwdriver through the fan grill, while it was still plugged in (yes, yes, stupidest idea ever). Needless to say I accidentally poked the main capacitor bank and since the middle of the screwdriver was touching the metal casing the bank was shorted to ground. All I remember was a loud POOF and sparks shooting at my face. I leapt back in utter terror, ripping the now-welded screwdriver out of the case with so much force when I let go of it, it flew almost 10 feet.

It was my first capacitor shorting experience.
 





That 650 farad bank look strange ..... undoubtly, the sign on the caps says 650 farad, but doubt they give 650 farad in total, as the auctioner say ..... they are interconnected in a strange way ..... if are all in parallel (but looking at them, it's not possible) it was 3900 farad :eek: ..... if are all in series, it's 650/6=108 farad total, if they are 2 paralleled series of 3 ones (seeing how they are posed in the holder, it seem the more probable combination), they are (650*2)/3=443.3 farad, and if they are 3 paralleled series of 2 ones, they are (650*3)/2=975 farad ..... doing series/parallel combinations is an usual way for manage the very low voltages of those capacitors, but there's no way for interconnect 6 elements all together and still get the same capacity of a single one, must be 4 or 9, for do that .....
 
what happens if you put the terminals of a fully charged cap in water
 
^ it discharge :D

water is not conductive enough for do too much more than just discharge it ..... at least, if you're not speaking about the 1000 Volt 200 farad units used in the AL-vapor electric cannon (LOL)
 
i have some this is whats on them anyone know what it means
BC 21509-532-02
3188gn602t400xpa2
6000UF-10+ 50%
400 vdc 450 surge
105c max ambiant362 0321 ab41003e
 
6000 microfarad 400 Volt DC

450 surge is the voltage at which they go in short circuit.

the rest are probably production numbers, except the max temperature of working ..... from a big power supply ?
 
unfortunately i dont have any, i had a personal network server i pieced together from old servers that i kept all my stuff on for backups, and both the server and my laptop got a trojan and i had to reformat my hard drive, but anyways, it was a somewhat simple circuit, i had a MOT(microwave oven transformer) running on a 30A variac, giving off 1200v that was run through a bridge rectifier, the bank took about a minute or two to charge, and the coil was 18g magnet wire that surprisingly never burnt up, oh and it was all switched with 3 SCR's in parallel for a higher surge capability.

unfortunately those days are over, my mom threw out my whole setup including my DMM =[
 
^ Moms always tend to throw away sons bigboy toys :/ My mother also always did that till the day she saw my PHR Laser O_o
 
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