This variable filter circuit was found in July 1975 Radio Electronics magazine. The circuit uses 3 general purpose op-amps like the 741 and must use a symmetrical source.
This circuit emits a loud sound in a headset when the driver who wears it nods while being in a...
With 3 flip-flops (which correspond to 1 integrated and a half) we can also make a divider by 8,...
This circuit is from the 1993 Motorola Linear Interface Circuits. The source does not have to be...