Capacitor discharge

Discussion in 'General Electronics Chat' started by Webby, Jun 30, 2008.

  1. Webby

    Thread Starter Active Member

    Jun 15, 2008
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    Hows the bestg way to discharge a capacitor fitted into a circuit, so it does not give me a shock?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    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.
     
  3. Wendy

    Moderator

    Mar 24, 2008
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    And if it glows, give it a few more seconds...

    :p
     
  4. Sparky

    AAC Fanatic!

    Aug 1, 2005
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    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.
     
  5. Webby

    Thread Starter Active Member

    Jun 15, 2008
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    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.
     
  6. thingmaker3

    Retired Moderator

    May 16, 2005
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    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.
     
  7. RiG615

    Active Member

    Nov 13, 2008
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    So could you kill someone with a capacitor??
    stick it in an outlet pull it out and touch someone with it?
     
  8. beenthere

    Retired Moderator

    Apr 20, 2004
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    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.
     
  9. studiot

    AAC Fanatic!

    Nov 9, 2007
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    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.
     
  10. Wendy

    Moderator

    Mar 24, 2008
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    IMO he deserved it. Shocks hurt.
     
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