Time Delay Circuit Diagram. 12v time delay relay adjustable on off timer using 555 astable mode in this circuit a timer with cyclic on off operations is designed. The circuit is based on the rc time delay and zener controlled switch.
We have to configure 555 timer in mono stable mode to build a timer. The circuit is based on the rc time delay and zener controlled switch. When the power to the circuit is turned on the 1000µf capacitor charges through the 100kω variable resistor.
The 555 timer starts timing when switched on.
Initially when no button is pressed the output of the 555 ic remains low and the circuit remains in this state until you press the start button and the capacitor c1 remains in discharged condition. That s where the rc comes from. Basically the capacitor takes time to charge up. We have to configure 555 timer in mono stable mode to build a timer.
