Electrical circuit diagram cycled on and off timer
Posted on Dec 11, 2010 7028
Electric start and stop the timer circuit diagram shown in the following cycle, LM555 adjustable duty cycle when the base integrated circuits multivibrator, the C3 charge-disch
arge circuit in series KH1, W1, KH2, W2, respectively, as electrical open, stop time coarse and fine adjustment. When the circuit operates power through R3, HK1 series resistance and W1, V2 charging to C3, 3 feet high output of IC, LED lights, the relay J pull its contacts connected load. When C3 voltage rises to 2/3 supply voltage, IC flip, relay releases. Meanwhile, C3 through V3, R4, 7 feet on HK2 series resistance W2 and IC-to-ground discharge. When the voltage drops to 1/3 C3 supply voltage, IC flip relay. So the cycle work. HK1, HK2 each block can increase or decrease the delay of 4.5 minutes, W1, W2 of the adjustment range of about 0-5 minutes.