1-minute delay (CB21408E)

This circuit with PUT is from a 1967 General Electric manual. The relay must have voltage according to the supply.

Two Transistor Siren (CB4210E)
This well-known siren configuration using complementary transistors is from a 1980s documentation. The...
Light Beam Operated Relay (CB4956E)
This circuit was found in an old American magazine and could make use of more modern components...
RIAA Preamp (CB1260E)
This circuit is from the Philips integrated circuits manual of 1990. It is intended for magnetic...