This circuit makes use of a low impedance microphone. The relay is according to the supply voltage which can be between 9 and 15 V. The operational gain is approximately 100.
Found in a 1968 documentation, this small amplifier was very popular at the time being used in...
Found in Electronics now, this circuit generates signals given by the formulas next to the...
The circuit shown can be used to send command pulses from a cogwheel or other sensor placed...