From: John Fields
Organization: Austin Instruments,Inc.
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Subject: Re: Help with relays please.
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NNTP-Posting-Date: Thu, 26 Sep 2002 12:15:03 CDT
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Date: Thu, 26 Sep 2002 17:15:03 GMT
Graham Holloway wrote:
> What's wrong with using a heavy duty starter solenoid? Must be a preferable
> solution to electronics.
Might be, but since a starter solenoid's normal duty cycle is so short
its coil might get _way_ hot if it has to do winch duty. OTOH, I
remember seeing starter-solenoid type relays for high current use so
yeah, if it can handle 400A, I agree that would be a better solution.
But... a quick look through an old Newark catalog and a trip to
http://www.stancor.com shows that the biggest thing they make is a
sealed DC contactor (P/N 586-902) which can handle a 600A inrush, but
only 200A continuously, for $56.02 in 1995 dollars. Two of them in
parallel (not a good idea) would be over $100, which doesn't compare
favorably with the cost of the MOSFET rig. I'm sure somebody other than
Stancor makes these kinds of relays, but I'll bet a solid state solution
comes out cheaper, no matter what.
Professional circuit designer