This circuit was found in Radio Electronics from the 90s. It converts capacitance into frequency in order to obtain a proportional voltage that can be measured in a common multimeter.
This circuit consists of two stages that each shift 180 degrees the signal. The circuit was...
This simple battery tester uses two transistors to drive LEDs of different colors, indicating the...
Found in 90s documentation from Analog Devices, this circuit employs operational amplifiers of the time....