Re: [CAD_CAM_EDM_DRO] Photoflash capacitors for EDM use

If you are going to use these caps make sure that you monitor the
temperature. Photo flash caps are probably not designed to be repeatedly
charged and discharged at the frequency that an EDM would use. If an
electrolytic cap gets hot enough it will vent or blow the end out. Makes
quite a bang and a mess.

For use in an EDM you want a cap with a low ESR (Equivalent Series
Resistance) so that it will not heat up when you charge and discharge it at
a high frequency. If you can find them in the right value oil filled caps
like the ones uses on motors work well. For scrounging a switching power
supply would be a good place to look.


At 06:45 PM 3/17/03 +0000, you wrote:

>A while ago someone suggested using photoflash capacitors in EDM
>usage. I found some at All Electronics, 150 mf at 350 volts and a
>nice compact size, 9/16" dia x 1.5" long, and only 75 cents apiece. I
>haven't hooked them up yet but it looks like they could be fitted
>right on an electrode feed head with really short leads to the
>electrode which should give a nice snap!. Richard.
>
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