> Would you consider "intelligent" MOSFET's? Would give you a space saving =
over
> relay, but possibly more expensive. One I've recently used (for driving s=
olenoids) is
> the ST Microelectronics VNQ690SP, 4 channel high side solid state relay, =
nominal
> 10A, 36V, fully protected.

I tried connecting a similar device directly across a  car battery and
turning it on. It survived without complaint. That sort of protection
is "useful".

A properly rated and protected MOSFET would work well in your application.

I'd personally usually use a MOSFET rather than a bipolar (both being
"transistors") in that sort of application, due to the greater ease of
drive in most cases wrt bipolars.

MOSFETs can and do fail any way they wish BUT do seem to have a soft
spot for S/C Drain-Source.   Sometimes hard S/C Drain-Source-Gate.
Designing the circuit so they are not over rated usually results in
very high reliability.



     Russell
--=20
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