This alarm oscillator was found in the December 1974 issue of Radio Electronics magazine. The power transistor must be equipped with a good heat sink. The Frequency basically is given by C1.
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...