Posted by dapj20 on Jul 01, 2021 in LED-Schematics, Opamp-Circuits, Test-Instruments
This is a LED Analog Meter, This can be used as a Resistance Meter and Low Impedance Voltmeter for Battery Levels.
Resistance measurement Current Source
To measure battery voltage, the R5-R12-R17 etc. part of the Reference Resistor Divider Network can be modified to suit. Shown here is for 4 LEDs, Use Three LM324 for 12 or More LEDs and Cascade as shown.