I actually need one measurement on +Ve and one on -Ve.

Basically, I'm trying to upgrade my "homebrew" power supply to display other
information.

Currently, there is a negative supply and a positive supply (which is why I
need two seperate measurements).

volt range is 1.2volts - ~16Volts max draw @ 1.0amp (I can actually squeeze
a little more out of it, but the regulators are only rated for 1.5 amps and
they start getting rather hot at 1 amp).

I've already gotten the volt meter portion figured out.

It doesn't have to be as accurate as accurate can be - I'd like it to be
accurate to within 1mA, but that might be asking too much for a first time
ammeter design ;)

I just really am not sure where to start.  I was thinking of inserting a
shunt resistor of sorts and branching off a parallel resistive circuit to
drop voltage down to the useable range of the pic and do some math based
upon the resistor I'm measuring across, but I realized I wasn't sure if this
really was the right way to go.

Any suggestions would be most appreciative.

-Tony

----- Original Message -----
From: "Larry Bradley" <lhbradley@IGS.NET>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Tuesday, October 29, 2002 5:10 PM
Subject: Re: [PIC]: Amp meter with pic?


> I've done a fair bit of that - in fact, my current project is a
volt-meter,
> ammeter, and amp-hour meter for my sailboat - measuring currents of +-\/-
> 100 amps.
>
> Tell us more about what you are doing. Do you want to measure the current
> in the +ve lead of the supply or the -ve lead? What sort of current? What
> sort of accuracy/precision?
>
> Larry
>
>
> At 04:44 PM 10/29/2002 -0600, you wrote:
> >Does anyone have any references on this type of thing?  Basically, I'm
> >working on a different circuit, but would like at times to randomly check
> >current flowing thru the main circuit.  I figure I need to use some sort
of
> >resistive network to get a volt reading for the adc, but I am not sure of
> >how to do it.
> >
> >-Tony
> >
> >--
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>
> Larry Bradley
> Orleans (Ottawa), Ontario, CANADA
>
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>

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