> I have modified the schematic as recommended by you. Hopefully it should
> work.
>
> http://i.imgur.com/vxChU.png

Chet an - that looks good.
It will work :-).
Supply decoupling cap on U1 at IC "a good idea".
MOSFET has nicel low Vgsth.
Datasheet here: http://www.fairchildsemi.com/ds/MT/MTD3055VL.pdf
Rdson is low enough gthat if driven g=3Dhard on dissipation should be
minimal at say 1A.

You could PWM it on/off
You could apply PWM via a resistor with cap on gate to ground to form
a variable DC voltage. This allows variable current drain with current
feedback  to pocessor  - noting that FET dissipation will rise when it
is used as a resistive load in this way.


     Russell
--=20
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