This 10-minute timer was found in the July 1994 Radio Electronics magazine. The relay must be sensitive to the supply voltage used. The capacitors determine time ranges.
The LS4558 integrated circuit is a double 741. The filter response curve is given next to the...
This circuit causes a bicolor LED or two LEDs of different colors to alternately flash at a...
This circuit, suggested by Texas Instruments, is based on the integrated TL497A, designed for...