This silencer or squelch preamp circuit was found in a documentation for radio amateurs. It completely mutes the circuit when there is no sound picked up by the microphone.
This small signal injector generator was found in the February 1971 issue of Radio Electronics magazine....
This amplifier, found in a 1981 publication, provides 15 W lHF power with a supply voltage of 14.4...
This simple passage alarm is powered by the power grid using an LDR as a sensor. The circuit is...