On-off timer

Crystal Patch 2520 2.5*2.0MM 32MHZ 32.000MHZ 1.6V~3.6V Universal OSC

As shown in the figure, it is a dual-purpose timer circuit. Adjusting the potentiometer RP can change the magnitude of the FET drain current Id, thereby changing the charging rate of the capacitor C3. To adjust the potentiometer, you can change the length of the timing. The larger the resistance of the potentiometer, the larger the adjustment range.