This is the power supply circuit for the amplifier in the previous circuit. The source is adjustable and uses power transistors of the time. The AC transistor must be mounted on a heat sink.
The battery charger suggested in the figure has its current limited by resistor R1. This component may...
This interesting 80's EDN circuit divides the input pulse frequency by a number given by n...
This circuit was found in a 1969 CQ magazine. It is intended for coupling telephones to radio...