Re: [CAD_CAM_EDM_DRO] : Charging Capacitors

Bill,

I was suggesting a safety discharge resistor for the cap bank to be
present after the reformation process is complete, and the cap bank is
placed into routine service. I didn't suggest it for the reformation
process.

A big cap bank with fresh, good caps could potentially store a lethal
charge for hours after power was disconnected. I believe that safe
design practice requires the presence of some means to automatically
discharge the cap bank in a short period of time when the power is
removed. A 10 second discharge time was suggested in the Tesla Coil
mailing list, and this would not severely stress the caps.

Hope that clarifies things.

Dave

wanliker@... wrote:

> When I reform capacitors I try to discharge them slowly until they are
> completely reformed, I always figured that a very fast discharge with its high
> current would place a stress on them that they really are not designed for.
> I can't prove the theory, but it just felt right to me, and I have had very
> good results with a slow reform process, and avoiding high discharge rates.
> Many of the discharge resistors of low value are using these capacitors
> almost like a photoflash capacitor, and they are not designed for that high
> current stressful operation.
>
> That's my opinion, and I am sticking to it.....................
> bill