Any sensor or piezo capsule can be used as a sensor in this circuit. The integrated circuit is also common in our days and a table of sensor voltage levels.
This circuit, found in a 1986 documentation, uses an optical sensor to count pulses and, in its...
Found in General Electric's 1969 documentation, this circuit uses two Foto Darlingtons to control...
The output voltage of this inverter depends on the employed transformer. The circuit is from a 90s...