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Old 12-10-2007, 07:04 PM
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Trevor Trevor is offline
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Quote:
Originally Posted by crazyhorse View Post
I thought induction was an AC phenomena. I could see if we were creating a positive to negative wave form, but were doing a simple digital switch. Granted there is quite a load, but I think the PLC's I have access to are capable of handling it.

I don't fool myself, I'm no expert. So enlighten me if I'm wrong.
When a DC supply to an inductive load is interrupted, there is revers discharge which must be dissipated. You may have seen a diode connected across relays for this purpose. Where contacts are involved in the switching, arcing can otherwise occur. In the case of AC, phase reversal during switching prevents the problem.
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