This power control for powers up to about 10 W uses wire potentiometers in an arrangement that allows to maintain the impedance. The circuit is from old European documentation.
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...