AC Power Outlet with Timer

Contents hide

1 Introduction

2 Hardware Components

3 NE555 IC Pinout

4 BT136 TRIAC Pinout

5 AC Power Outlet Circuit

6 Working Explanation

7 Application and Uses

Introduction

Wastage of anything is not a good idea; and when it comes to electricity, it is also not good economically. Higher electricity bills can make your life difficult, moreover, this wastage is also not favorable for the country’s economy. So, to save energy, in this tutorial, we are going to make an “AC power outlet with Timer”.

You may use an outlet timer to switch appliances on and off at certain periods. It may be used to manage your home’s lighting, heating, and air conditioning.

Hardware Components

The following components are required to make AC Power Outlet Circuit

S.no	Component	Value	Qty
1.	IC	NE555 Timer	1
2.	Bride Rectifier Diode	1N4007	1
3.	TRIAC	BT136	1
4.	Zener Diode	9v	1
5.	LED Green	–	1
6.	Electrolyte Capacitor	470uf	2
7.	Ceramic Capacitor	100nF	1
8.	Resistor	2.2K, 2.2M, 47K, 100 Ohm	1,1,1,1

NE555 IC Pinout

For a detailed description of pinout, dimension features, and specifications download the datasheet of 555 Timer

BT136 TRIAC Pinout

For a detailed description of pinout, dimension features, and specifications download the datasheet of BT136

AC Power Outlet Circuit

Working Explanation

This circuit uses the mains AC power provided for the AC plug point and does not require a step-down transformer. When there is no power supply, the X-rated capacitor C4 and resistor R3 reduce the supply through capacitive reactance, and the resistor R3 discharges the supply across the capacitor. The bridge rectifier converts AC to DC, and the Zener diode ZD1 regulates the DC supply to keep it constant near 9 volts. Finally, the C3 capacitor filters the DC supply. One can adjust the time delay by changing the R2 and C1 values in the timer circuit, which uses an IC555 that is working as an astable multivibrator to create longer-duration timing pulses.

The BT136 TRIAC is wired between both the AC socket and the neutral supply line, with the gate terminal linked to the timer IC’s output pin. Whenever the high pulse rises, the TRIAC turns on and makes power accessible at the mains socket for a certain amount of time. And, when the low pulse from the timer IC is received, the TRIAC goes off, and there will be no power supply available at the mains socket. In this manner, we can make any electrical device turn ON and OFF regularly.