Re: E-stop relay welds contacts for load dump resistor

I might not have described my proposed use of the condenser cap properly. I was thinking of wiring it like this:

+ Terminal on power supply Cap---> 7 ohm
resistor---> + terminal on "condenser" Cap. - terminal on "condenser" cap goes to NC contacts on relay---> Ground buss bar. When the relay
de-energizes, the Capacitor then has a path to ground, of course, to bleed off
it's charge. I am speculating that the "condenser" cap will have to absorb current to charge, while it is simultaneously slowly passing current through through the relay contacts to ground. Kind of like a big hydraulic accumulator would absorb a pressure pulse or spike. Is my speculation correct or am I missing an obvious piece of electronics theory? Thanks!

Dan.
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--- In CAD_CAM_EDM_DRO@yahoogroups.com, David Speck <Dave@...> wrote:

>
> If the condenser bridges the relay contacts, you will pass significant
> AC current, and there will be some voltage applied to your transformer
> even when the relay is open. A capacitor looks like a resistor to AC.
> Worse than that, when the relay does close, the entire stored energy of
> the cap will discharge across your contactor, so you will be back in
> spot weld city again. Old point systems in auto ignitions had to be
> replaced periodically, as the contacts burned away, but they were DC
> systems, so there was no AC leakage through the cap.
>
> Dave