Re: [CAD_CAM_EDM_DRO] EDM Capacitors

Ian W. Wright wrote:

><Seems decent caps of high ratings are hard <to find. a Motor run
><capacitor is easy to find, are rated in high <voltages, should work
><but are limited to about 50uF in capacities.
>
>I have had some success with the capacitors out of an old, professional,
>flashgun - the type newspaper hacks and studios used to use. As in this
>case, you can put a number of capacitors in parallel to increase the overall
>capacitance. The one thing you do need to check though is that the
>capacitors will withstand continually charging and shorting out - most of
>the radio types won't whereas the flashgun types are made for just such an
>application.
>
>

I have used oil-paper and mylar capacitors for my mini-EDM setup, and
they work well.
They are the type that can handle this sort of severe service, unlike
electrolytic types, that
will probably suffer from this. The peak currents using my setup in the
3 - 6 uF range at
30 V is probably in the 100 - 250 Amp range.

Jon