When we forgot to turn off the home appliance then the electricity bill will turn on us, so it is important to turn off any Electrical appliance when not in use inorder to save energy and money.
Here a simple circuit designed to Automatically turn ON/OFF home appliance at particular time with the help of IC555 timer and AC power socket.
Construction and Working
This circuit is designed to work without step down transformer, it uses the mains AC supply provided for AC plug point. The X rated capacitor C4 and resistor R3 decreases the AC supply through capacitive reactance and parallel Resistor R3 discharges the supply across capacitor when there is no power supply. The bridge Rectifier converts AC supply into DC and zener diode ZD1 Regulates the DC supply as constant near to 9 volts, C3 capacitor filters DC supply before it reaches the timer circuit.
The Timer circuit using IC555 designed as Astable multivibrator to produce long duration timing pulse, we can vary the time delay by using R2 and C1 values.
The BT136 TRIAC is connected between the AC socket and neutral supply line, Gate terminal is connected with output pin of timer IC. When the high pulse rise it turn ON the TRIAC and makes power supply available at mains socket for particular time period.
TRIAC turned off when the low pulse came from the timer IC, then there is no power supply available at mains socket by the way we can make any electrical appliance to turn ON and OFF periodically.
BT136 series TRIACs