Using a 709 integrated circuit this circuit was found in the June 1972 issue of Radio Electronics magazine. More modern operational equivalents can be used. The power supply is symmetrical.
The configuration shown in the figure has been requested a lot by many readers who need a circuit...
This timer uses common components today. It activates a relay after intervals that can be adjusted up...
We found this circuit in an English magazine from 1980. The circuit can be easily assembled even...