Found in the July 1970 Radio Electronics magazine, this circuit has an adjustable activation time that depends on capacitor C1. The SCR may be a 106 series equivalent.
This oscillator circuit for sinusoidal audio signals with operational 741 requires a symmetrical power...
Found in a 1974 Radio Shack documentation. This circuit must have a connection to the ground of...
This sensitive circuit detects the live pole of a power grid or outlet. The circuit makes use of a high...