> Regarding the comments on MOSFETs...Can anyone tell me if there is a
> MOSFET that can control say 100 Amps?  I would like to replace a
> mechanical battery switch with a MOSFET one.  For this I would like a
> minimum of on-resistance, say less than 0.1 ohms if possible.  Of
> course, I realize that careful attention will have to be paid to the
> thermal design aspect.  Does any such device exist?  If so, please
> point me to its data sheet.
>
> TIA
>
> Jim Manzari
>
I think you'd want *much* less than 0.1 ohms

P=I^2R =100*100*0.1 = 1000 Watts!!!!

Thats a lot of heat to get rid of.  Would this be 100 Amps continuous or
pulsed?  If the average current is lower, there are many devices readily
available that can take 25 Amps or more peak current. Bearing in mind that
the gate takes no current (unless changing state) you could by a load of
these and parallel them up.  This is the approach taken by the PWM motor
controllers used for Radio controlled models.

Mike Rigby-Jones
mrjones@nortel.co.uk