[HH] low battery indicator: reducing voltage divider current

[Tom Metro]

Greg London wrote:
> If I put the 12v battery to the Gate on a n channel mosfet,
> have the Source tied to ground, and have a 10k ohm resistor
> from the Drain to a programmable output of the microcontroller,
> then the Gate will effectively give me zero current there...
> 
> The problem is the transistor amplification factor is different
> from transistor to transistor...

You're just reiterating a solution you described in your prior posting,
right?

You made the problems with this approach clear the first time, so lets
move on to other options...


> I can't think of a way to do it with a single transistor.
> I think it needs at least two transistors or an optocoupler.

OK, so what's wrong with two transistors? (bipolar or MOSFET)

 -Tom