david schmidt wrote:

> The reason I want to use a V-F convertor for an amp-hour meter is
> - very simple, can use the lowest cost PIC
> - no need to come up with a fast sampling scheme (A/D convertor may not
> keep up)
> - more resolution, bigger dynamic range - just count the pulses
> - overall should prove to be more accurate since the voltage coming from
> the shunt will be continuously monitored.
> - easier to deal with RF noise coming from a DC-AC inverter also connected to
> the batteries.
> - pretty foolproof
>
> Plus I have found some V-F ic's with built in amplification, 0.1% linearity,
> 80dB dynamic range.
>
> BTW, since I'm only going to see 0 to 50mV signal, does the OP291 have a
> very low
> input voltage offsett and thermal drift?
>
> Dave

Have a look at the power metering chips at http://sames.co.za. They were
designed here in South Africa, are cheap and reliable (root, root).

--
Friendly Regards

Tjaart van der Walt
mailto:tjaart@wasp.co.za
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