1-minute delay (CB21408E)

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

10 A Output Amplifier LM12 (CB19035E)
This circuit was found in a National Semiconductor manual that is now a Texas group company. The...
Band Switch (CB21254E)
This switch or band selector for receivers was found in a Popular Electronics from the 1990s. The...
Low Frequency Hartley Oscillator (CB867E)
L1 is the secunday wound of a common power transformer with voltages between 6 and 12 V and...