Capacitive Relay (T1527E)

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

600W heating control (CB21383E)
Found in old American documentation, this circuit is intended for the control of heating elements. The...
Pyroelectric Detector (CB25377E)
This “people detector” with pyroelectric sensor was found in the April 1991 issue of Radio...
Amplifier 50 Wrms (CB13214E)
This circuit is from an old American publication, therefore using transistors that can no longer be...