Re: Discharging HV Caps

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Ben,

If it is an MMC, placing 10 Meg bleeder resistors across each cap is an
excellent and transparent way to drain the caps automatically.  For a non MMC
cap, you can string together a bunch of resistors to accomplish the same
thing.  These resistors can stay in place since they do not affect the normal
operation of the cap in TC use.

If you have a BIG cap, you need to discharge,  Shorting it directly out is
probably not a great idea.  Depending on the voltage and value, you may get a
much bigger spark than you bargained for =:O  Also a direct short can draw
fantastic currents from a pulse cap that can damage it.  You should have
something to limit the current.  A big wire wound resistor works well.  Say a
10K 100 watt resistor on the end of a long PVC pipe.  You can then drain the
cap from a safe distance in a controlled way.

It all sort of depends on what type (value voltage) of cap you are trying to
discharge, but a resistor on the end of a plastic pipe (with wires sticking out
to make contact) is a pretty good way to go.  The long pipe is important 
incase you slip and short it or the resistor blows you will not be damaged.  In
my case, the long pipe also helps when discharging high power equipment that I
still have connected to the mains which blows the resistor to bits ;-))

Cheers,

        Terry



At 11:34 AM 6/5/2001 -0500, you wrote: 
>
> WHat is a convenient way to dischage HV caps that is still safe?
> Ben