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Solution for a regulation input circuit in a PIC based 4 digit voltmeter

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Fragrance

Fragrance

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hi

i have made a pic based 4 digit voltmeter what i need a regulation input circuit that work upto 250volt where as pic input rang is 0 to 5 volt

regards
Fragrance
 

volt meter help

Typically, this is just a precision resistor divider and some electronic switches. Assume 1M ohm at 250V. Then the series resistor is 980K and the resistor to ground is 20K. As you range downward you switch out the 20K and switch in a larger resistor. Some ADC chips have auto-range built in. Since you built your own using a PIC, then you have to do it externally.
Also include a clamping zener across the resistor to ground to protect the PIC for over voltage inputs or errors in range selection.
 

Re: volt meter help

You could try this or have a look at it, I've not used it but it can go up to 750V I think, It's from a fluke meter I will be in the proccess of trying it out to see how it works

What you mean by a 4 digit display LCD or LED'S
 

Re: volt meter help

wizpic said:
You could try this or have a look at it, I've not used it but it can go up to 750V I think, It's from a fluke meter I will be in the proccess of trying it out to see how it works

What you mean by a 4 digit display LCD or LED'S
Click to expand...

thanks wizpic i have made this meter on led display the schematic uploaded by you is complecated i just need simple solution

regards
Fragrance
 

volt meter help

Fragrance ,
I try and find aonther simple version, 250V is a big input and I would not trust a resistor divider network and I would not recomemnd adding a zener diode on the input to the pic this could casue false reading's
wiz
 

Re: volt meter help

Fragrance here is the full book of the fluke meter

hope it helps you

wizpic
 

    Fragrance

    Fragrance

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