What is the correct way to discarge a high voltage capacitor?

[gast]

Hello everyone,   
can someone tell me what is the correct und surest way to discharge a high voltage capacitor? 
I refer to circuits of this type (FEP) http://jnaudin.free.fr/html/afep01.htm.   

I dont want to get an electrical shock during such exepriements.   
Is it a good idea to attach a piece of metal on a wooden stick and shorten the capacitor with 
this metal after switching the power of the circuit off. Or is it better to use a resistor for a slower discharging?   

Anybody who can speak from his own experience?   

Regards, Gast

[Markus]

It depends on the energy stored in the capacitor.
I have built several HV capacitors and no problems with shortening them. (e.g. 30kV, 20nF ->9J = 9Ws) W=0,5*U?*C
By the way: I used this capacitor for a Tesla Coil where it was shortened 200 times/second.

If you have high energy capacitors ~2kJ and more you should be careful with shortening them. It can destroy the dielectric.

Hope this helps.

[gast]

Markus, yes I think this helps. :-) Thank's for the formula.

What's with your Tesla coil? Do you have to discharge the capacitor on the top of the Tesla coil after finish your experiements? What way you discharge it? Simply by connecting it with the ground of your room?

I would be afraid touching the thing awhile after switching off the teslacoil.

Regards, Gast

Hmm, seems that I am a coward in the matter of high voltages ;-)

[Markus]

The secondary capacity of a Tesla Coil is this "metal hat" called torus on top of the big coil. The bigger it is (surface area) the more energy can be stored on it. You can calculate the capacity but I?m too lazy to look for the formula now. If this torus has a charge of lets say 100kV and you touch it you will probably get a nice shock,..but it won?t kill you. Usually the the secondary coil is grounded and the torus will be discharged as soon as you switch off the Tesla Coil.

If you want to be sure that there is no HV left on any parts (capacitors, electrodes,...) simply connect them with the ground.

But do not use the ground connection of the grid. It would probalbly work but it is risky. If there are electronic parts like "FI-switches" (don?t know how you call them English) they can be damaged. I used the warm-water heater as ground. The best solution would be to connect it to the lightning conductor of your house.