good circuits for a noob to learn!

I did a "controled" experiment and hooked up a 4700 uf electrolytic backwards with about an amp through it.
It first got hot and about 20 seconds later -POP HISS. It made a small split in the side and steam came out.
I cut another one open and it has like a gell/liquid soaking the paper.
I am guessing that when it breaks down inside, the heat from the short turns part of the electrolyte to steam and it builds preasure in the case untill it ruptures.

sam2 said:

I did a "controled" experiment and hooked up a 4700 uf electrolytic backwards with about an amp through it.
It first got hot and about 20 seconds later -POP HISS. It made a small split in the side and steam came out.
I cut another one open and it has like a gell/liquid soaking the paper.
I am guessing that when it breaks down inside, the heat from the short turns part of the electrolyte to steam and it builds preasure in the case untill it ruptures.

Click to expand...

Modern capacitors have safety vents in the top (the three lines you can see), these let them split easily and vent the electrolyte safely.

Older capacitors didn't have this feature, so could easily explode! - there's still a hole in the ceiling at work where a capacitor took off like a rocket, just missed my head, and punched a hole in the ceiling.

Many years ago I repaired an old valve TV, and the main electrolytic had exploded, it was mounted horizontally under a metal clamp, but the rocket action had thrown the can forward and crumpled it against the rear of the CRT. All the paper and foil had gone backwards and forced the back of the set off.

I have once discharged 500V 2350:mu:F through a 10V 2.2:mu:F capacitor, it was sunk into some polystyrene to prevent shards flying, but it split the polystyrene and melted a large portion, the hot expanding gases had a lot of force.

wow this sounds like alot of fun!!