On Wednesday 31 March 2004 15:31, Spehro Pefhany wrote:
> At 02:33 PM 3/31/2004 +0200, you wrote:
> >Hi
> >
> >I need to measure the following with a pic-micro controller:
> >
> >   - DC voltage range from 0Vdc to 230Vdc with at least 1V intervals.
> >
> >   - AC voltage range from 0Vac to 440Vrms with at least 1V intervals.
> >
> >I need complete isolation between the high voltage section and the micro
> >controller. I have an idea for AC, but the how do I isolate the DC?
>
> One method is to use a linear optoisolator such as the Infineon IL300.
> You'll need power on the high voltage side,

Well, the specified range includes 0V. So you need to create your own floating
power supply. Well, shouldn't be very hard to build.

> Or just put a microcontroller with ADC on the hot side with an isolated
> digital serial link. This method probably gives you the most bang for
> the Rand, but the bandwidth may be limited by the isolated serial
> interface.

Same thing here. Few microcontrollers run on 0V (well, i haven't found one
with on-board batteries. That'd be a nice peripheral). But I think this might
be the most accurate solution :o)

Koen

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