This circuit for alternating current loads has a built-in timer. SCR2 is according to the motor current and must be equipped with a heat sink. The circuit is from a 70s GE documentation.
This circuit was found in an American publication from the 50's. The transistors are made of...
The circuit shown is an amplifier for medium impedance headphones including bass and treble...
This circuit for an optical audio link using LED or LASER was found in a 90s QST magazine. The circuit...