This 555 IC circuit was found in June 1984 Radio Electronics magazine. This circuit detects a change in the signal and can power a relay or other warning system.
The integrated 4017, a C-MOS counter, is one of the most popular in the design of sequences,...
This simple very low power circuit can be used in a battery powered infrared tone trigger. We...
This timer controls two relays, each with a different timing, activated separately. The circuit is from...