View Full Version : Electricuted my finger!

4th June 2009, 17:12
While repairing my Buffalo Linkstation today I accidentally touched the capacitor on the small PSU inside the unit with my ring finger. That bloody hurt I can tell you. I felt it shoot up my arm and into the left of my chest before I managed to remove my finger. :o

I really should be more careful.

And the finger is still quite numb an hour or so later. :huh:

4th June 2009, 17:14
Last time i did the same was with the ZX Spectrum PSU....

Demon Cleaner
4th June 2009, 17:54
Never trust a capacitor ;) And I guess this was still a small one?

4th June 2009, 18:01
One day, i was playing the electrician in my old appartment (an old piece of junk), i had in mind to repair a plug and i don't know how i did it, but i ended up touching the 2 wires with my thumb... That was painful and creepy...

5th June 2009, 00:24
Glad you're ok.

Never underestimate electrical safety. It only takes a small current across your heart to cause serious issues. Many times the shortest path to ground won't be through your heart - but why take the risk?

5th June 2009, 01:51
Never trust a capacitor ;) And I guess this was still a small one?

Reasonably large. It was about 1 cm in diameter. No idea what its actual rating was though.

Annoying thing was that I was being quite careful and I'm not sure how my finger ended up touching it. Just goes to show.

Stephen Coates
5th June 2009, 05:56
I'm quite pleased to be able to say I have never been electrocuted.

If it is of any interest:

Current Levels
1-3mA - Slight tingling
10-15mA - Muscles begin to tighten. Difficult to release a held object
25-30mA - Muscles really tight. No control. Dangerous
Over 50mA - Ventricular fibrillation of the heart occurs. Can be lethal

Of course that is not likely to cause any difficulty with a small capacitor which will discharge very quickly and not supply much current anyway, but a big one may cause some damage.

If you tell us the voltage rating and capacitance of the capacitor, and the impedance of your body at the time (you could guess this based on humidity etc) we should be able to calculate how much current the capacitor supplied and how long it took to discharge.

5th June 2009, 07:08
One summer going home from a party I took a bad shortcut and ended up stuck in an electric fence. Took about 1minut to get free, the shocks made it hard. Even in my drunk state it was a pain hard to describe, and it was a lot of that pain there for that minute......

5th June 2009, 13:17
I still remember waking up in the middle of the night as a kid, where I tried to turn my reading lamp on and nothing happened. That wasn't special, the bulb had a habit of unscrewing itself from the socket so I often had to reach up and tighten it to get some light. So after sleepily flicking the swithch I blindly reached into the lamp to tighten the bulb I thought had come loose, forgetting that I'd removed the bulb the previous day because it had died. 220 volts through the fingers, baby! Took a while before I fell asleep again, I can tell you that much.