Capacitive Relay (T1527E)

Found in Popular Electronics from August 1956 this sensitive two-tube relay is powered directly from the mains power supply.

Lamp or motor control (CB7222E)
This circuit can control the power from 0 to 70% of the maximum power on a load. The circuit was...
Headphone Amplifier (CB24080E)
This circuit is from a Radio Electronics from October 1970. The circuit uses transistors from that...
Baxandall with CA3140 (CB11981E)
This tone control was obtained from the CA3140 datasheet, originally created by RCA. The CA3140...