We found this circuit in documentation from the 90s. Instead of a voltmeter, you can use the voltage scale of a multimeter. The circuit tests batteries under load.
This circuit is from a March 1978 Radio Electronics magazine article that showed how to build it....
This circuit was obtained from an article in Radio Electronics magazine in October 1966. It...
In the figure we have a bistable circuit that activates LEDs from touch rings and turns off data...