This circuit is from Motorola's Linear Interface ICs of 1993. The circuit can be powered by symmetrical 6 to 12 V voltages and for a stereo version, two channels must be built.
This variable filter circuit was found in July 1975 Radio Electronics magazine. The circuit uses 3...
This Hughes circuit is from 1968. Equivalent modern components can be used. The input impedance is...
This circuit emits a warning sound when night falls. The circuit is from a Hands On Electronics from...