I Just Remembered

[StratDudeDan]

when you accidentally wire an electrolytic capacitor backwards, they pop. i totally forgot about that since high school electronics class until this morning.

i was working last night on a board, and i was freaking tired, but hell-bent on getting it laid out and soldered. and i did.

this morning, went in to test and troubleshoot, applied power, about 20 seconds later POP! made me giggle, strangely enough, 'cause i remember intentionally wiring them backwards across the leads of our power supplies just for that.

i also found out something new today. for some strange reason, splicing a new grounded power cable onto my amp kicked my ass...it just took forever and was the most uncooperative SOB i've worked with in my life...

[lovekraft]

Just a note of warning - if you do this with large electrolytics in a high voltage setting (like a tube power supply), the pop! becomes much more of a BANG!, and dangerous shrapnel can result - I won't bother telling you how I found that out.

[MikeB]

yeah, my mate did that with quite a large cap, not that big, but big enough. it blew up in his face, and bits flew about. he hasnt lived it down since!

[Paul Marossy]

I've always wondered what happens to them when you apply, oh, let's say twice the voltage that they are rated for... do they explode or what?

[thedoctor]

I have holes in the isulation on the cieling of our old workshop. They came form 8800mfd 550VDC caps seeing about 1000 VDC. Lots of stink, big fireball, big boom. The new design electolytics for low power filtering and conditioning claim to be built so precise that polarity no longer matters. Those holes in the cieling keep me from ever trying that theory.

[Paul Marossy]

Holes in the ceiling?! Whoa!

[skibum5545]

Reminds me of a time a cap popped in my computer... a sizzling sound, pop, and then all sorts of weirdness.

I opened the case and spotted the problem: the blown cap had actually put a dent in the metal frame of the case!

Electricity is powerful stuff, and sometimes it takes a good bang to remind us of these things.

[JohnnyG]

i still have a little pea sized lump on the inside of my right arm. reached across a breadboard to turn the power on to a project at school and i sent 25 volts through a little 18 volt electrolytic. the metal case went straight up into my arm and then bounced off and half way acrossthe room.

i still got full marks for safety tho