Two-tube regenerative receiver (T1595E)

This circuit is from a Radio Electronics from 1949. The circuit is battery powered and has high impedance listening.

Photo alarm with the 555 (CB6854E)
This traditional configuration with the 555 was obtained in an 80s Hands-On Electronics. The relay...
Photoelectric relay (CB23650E)
This two-transistor circuit is from a Radio Electronics magazine from April 1965. The transistors are...
AC voltage control (CB8904E)
This circuit was found in a 90s Hands On Electronics. The semiconductor component is a Triac of...