This amplifier with antique germanium transistors is from a 1968 publication. The circuit provides some watts of power with excellent sound quality. This is the configuration used in commercial equipment of the time.
This circuit, with an operational amplifier, was found in the Motorola Dataar Linear of 1990. The...
In the fist circuit the alarm triggers on when any sensor is CUT. In the second circuit the alarm...
This circuit for a digital module was found in the September 1989 Radio Electronics magazine. The...