This circuit was originally intended for reading movie soundtracks. The circuit is from 1967 and was found in an English publication. The sensor is semiconductor type.
This microphone preamp allows the use of high impedance crystal microphones with amplifiers that have...
This is the radio receiver for the previous infrared alarm radio transmitter. It contains the...
This amplifier for a sinusoidal function generator uses a 741 integrated circuit. The circuit is...