Capacitor discharge

beenthere

Joined Apr 20, 2004
15,819
Bridge the terminals with a resistor. If the voltage is 12 volts or under, there is no shock hazard. otherwise, use 1000 ohms for a few seconds.
 

Sparky

Joined Aug 1, 2005
75
You didn't mention what type of circuit the cap is in.

Depending upon the circuit - the situation could be lethal.

I think immediately of the inside of a TV.
 

Thread Starter

Webby

Joined Jun 15, 2008
66
Hi the circuit is a 240v steam cleaner for motor vehicles the contacts to the capacitor have poor connections so just incase the system is still active just wondered how the best way was to discharge the capacitor to renew the connections.
 

thingmaker3

Joined May 16, 2005
5,083
1) Make darn certain that the power is off and the cleaner is disconnected from power.

2) Put the resistor Beenthere mentioned across the capacitor using something other than your fingers. If there is enough room, you could use a fuse-pulling tool to position the resistor all at once. If not, connect some leads and alligator clips to the resistor. Use a fuse puller or insulated pliers to connect the alligator clips one at a time to the cap leads.
 

beenthere

Joined Apr 20, 2004
15,819
That's an old trick. But it only works for an electrolytic type. Just jam it in and run - the cap will explode in a few seconds. AC tends not to leave charge on capacitors.

If you place a charge on a capacitor using DC, then you can play another trick. You toss it to your buddy and run. He will get a shock, become angry, and chase you.

About the worst thing that can happen from the charge in a capacitor is causing yourself damage when it shocks you and you snatch your hand free. You can knock things over or drive your elbow into something solid and painful.
 

studiot

Joined Nov 9, 2007
4,998
the worst thing that can happen
I remember one works where a practical joker received a broken jaw after being thumped by an irate victim. The joker used to charge up capacitors and leave them in peoples' jacket pockets.

Don't do it.
 
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