This Public Address amplifier was found in a 1947 amplifier manual. The power supply uses two transformers with two rectifier tubes.
This circuit is suggested by General Electric in 1966 documentation. The Triac must match the...
This circuit was suggested by Popular Elecronics from the 90's. The circuit has high input...
This circuit is nothing more than a turn signal for two alternating LEDs that can decorate a robot...