Don Foreman wrote:
On Mon, 17 Oct 2005 00:39:48 +0000 (UTC), Cydrome Leader
wrote:

The physical case sounds really large for such a capacitor, especially a
mica one.

Induction heater polypropylene caps might be an acceptable replacement.

Does anybody know what frequenecy these welders operate at, and possible
RMS current levels these caps see?

The freq is typically somewhere between 1 and 8 MHz. You can
figure the RMS current from the voltage level and freq. That rating
would be very conservative because it's basically like a Marconi spark
xmtr rather than a CW-excited tank at the operative freq.

I just dug up two old Cornell Dublier mica transmitting caps. Each is
rated 0.004uF at 12kV and 22A @ 3MHz. Used in series they would provide
the correct capacitance of 0.002uF and should be quite suitable for 6kV
use. They would fit into an approximately 6" cube box each.

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