Circuit Flow Process

Generally, the circuit given by the demonstrator is shown as diagram above. Actually this circuit is act as auto switch, which can switch the load on or off automatically. For this circuit, the light dependent resistor (LDR) will give the command to the 555 timer IC. The command is send to the timer when got shadow or no lights fall on the LDR. The timer will receive the command on the pin 2, which is trigger input. The timer will process the input and give the output to the relay. The timer required a period of time to receive the input and a period the time to process the output. The time can be calculated by multiplied the resistor (R₂) with the capacitor (C₁) and In3. The output command will control the coil on the relay, which it can switch on the load or switch off the load. The load will switch off when no light fall on the LDR and switch on when got the light flow on the LDR.