> when I did it from memory. You're right, any stable reference
> can be used but since Jinx brought it up (LM335-2.5), I decided
> to reference it

The circuit I looked at was in this month's Silicon Chip. It doesn't
use a PIC so there's no need for a 5V supply. I agree that even
so it would still have been cheaper to use a 5V regulator than a
more expensive Vref IC. I've found the 78L05 is always between
4.98 and 5.02, which is good enough. It just happened that I was
thinking about battery protection soon before I picked up this
issue

Re: the Silicon Chip circuit

http://home.clear.net.nz/pages/joecolquitt/bat_guard.html

From time to time, it's asked how to implement a high-side
FET switch. SC detail the problems of driving high-side FETs
and have chosen a pulse transformer, using a toroid and a
few windings, to do it. Has this been offered as a solution
by the list before ? If not, any comments ?

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