At 06:38 PM 1/23/02 -0700, jb wrote:
>My MOSFET knowledge is pretty limited, not sure how to drive that with a
>PIC running at 5V. Wouldn't a PNP power transistor do essentially the same
>thing since the CE drop in saturation is what, maybe .2-.4V? Use a 2n2222
>to drive the base on the PNP hard with the PIC output, and use the A/D
>input as you said to detect hi/low thresholds?

That's why the P-Mos. Ground is on.
So you put a 2N3904 or similar on the PIC output to slam the gate to
ground, and a pullup resistor on the gate to the drain to turn the FET off,
when the '04 is off.

Don't forget a base pulldown resistor on the '04 so it's off when the PIC
is in reset or crashed!


>Perhaps the MOSFET idea is better, but absent much experience with them,
>I'm trying to stick with what I know.

Learning is good. :) If it makes your head hurt, that's good.
Learn till your head explodes, then back off a notch.

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