In the figure we have an IF amplifier step using a MOSFET. The circuit was found in a 1980s documentation, intended for FM receivers of the time.
This sonic relay circuit is driven by a high-pitched sound picked up by a microphone that can be a...
Found in a 1966 General Electric manual, this circuit provides a delay in starting. The motor is...
This amplifier uses an operational amplifier from the time. It was found in the February 1970...