Charging time relay circuit 2 It is a long delay circuit. When the capacitor C is 5000yF, the delay can be up to 1. 3h. By transistors VTi and regulator VS2, VS3 group as a con
stant current source, in order to improve the accuracy of the delay. Press the button SB, KA relay pull, VTz off, VT3 conduction. After after a delay, VTz conduction, VT3 deadline, KA released. Adjustment potentiometer RP, adjust the delay time.