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Something to do with cheap multimeters

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NiHaoMike:
http://hackaday.com/2010/06/24/multi-multimeter-clock/

saturation:
Nice is it digital or analog?   ;D

NiHaoMike:
The ones pictured are analog, but digital meters should work. Might need some low pass filtering. A "floating" power supply would be needed to power the meters, but I think they can share one if the negative inputs are connected together. A cheap CEN-TECH I have (now dedicated to monitoring bench power supply current, powered by a small AC adapter) uses only 0.8mA at 9v. The positive side floats about 3v above the negative input, remaining constant despite battery voltage changes, so it seems like there's a zener diode or something. That can probably be supplied using a resistor to 5v. The negative side varies, so it probably isn't too critical. A charge pump run from a PIC output should be able to run it.

Kiriakos-GR:
He needs another one meter , to use it as  " Alarm " function ...  ( continuity mode )   ;D  ;D  ;D

saturation:
Thanks NiHao, but what I meant is the actual clock operation is done by a PIC 16F628A which outputs a proportionate current to read as hour, min and seconds.  So its a DAC output being read by real analog gauges.  So is it analog, or digital?  ;D







--- Quote from: NiHaoMike on June 24, 2010, 11:19:01 pm ---The ones pictured are analog, but digital meters should work. Might need some low pass filtering. A "floating" power supply would be needed to power the meters, but I think they can share one if the negative inputs are connected together. A cheap CEN-TECH I have (now dedicated to monitoring bench power supply current, powered by a small AC adapter) uses only 0.8mA at 9v. The positive side floats about 3v above the negative input, remaining constant despite battery voltage changes, so it seems like there's a zener diode or something. That can probably be supplied using a resistor to 5v. The negative side varies, so it probably isn't too critical. A charge pump run from a PIC output should be able to run it.

--- End quote ---

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