With this circuit it is possible to obtain a voltage of -5 V from a 5 V source. The circuit is from Radio Electronics from May 1982. The maximum current is around 80 mA.
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...