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Touch On Touch Off Switch Circuit Using 555 timer

In this simple Touch lamp switch circuit, we have used timer IC 555 operated as ON and OFF. By using this circuit you can turn ON and OFF a device by simply touching the Touch Plates or metal used as a sensor. If the touch plates are placed at a convenient place, we do not require moving from our location to turn them on and off the device. The important feature of this circuit is that we will not get any electrical shock which we sometimes get while using normal switches.

Components Required for the Touch lamp switch

555 Timer IC
3.3MΩ Resistor (1/4 Watt)
1MΩ Resistor (1/4 Watt)
1KΩ Resistor (1/4 Watt)
A bulb with holder (regular or CFL)
5V Relay
BC547 NPN Transistor
1N4007 PNP Junction Diode

Touch lamp circuit diagram

The design of the touch lamp Switch circuit is very simple. We have connected pins no 8 and 4 of the 555 with VCC supply. Pin 1 is connected to GND and 5V respectively. Pin 2 of the IC is pulled HIGH using a 3.3 MΩ Resistor. Pin 6 is pulled LOW using a 1 MΩ Resistor.

As shown in the diagram two touch plates are connected. In the case of the touch-to-ON plate, one end is connected to pin 2 and the other end is connected to – supply. Similarly, one end of the touch-to-OFF plate is connected to VCC (5v) and the other end is connected to Pin 6.

Working on the touch lamp switch

After Connecting the circuit as per the circuit diagram and apply the 5v power supply.
Touch the “ON” plate with your finger and to turn OFF the device, touch the OFF plate as shown in the circuit diagram.
As the power supply is applied to the circuit, the device connected through the relay (we have connected the AC bulb) remains OFF. Now if we observe the circuit diagram, Pin 2 of 555 IC is pulled HIGH and Pin 6 is Pulled LOW.
As we touch the ON plate, the voltage at Pin 2 of the 555 IC becomes LOW. As Pin 6 is already LOW, the output at Pin 3 becomes HIGH.
This is connected to the Relay through the Transistor BC 547, the Transistor will be turned ON and it will activate the Relay, and the device gets switched ON.
At this point voltage at pin 6 is zero as it pulled LOW by default and the voltage at Pin 2 of IC is HIGH.
Now, as we touch the OFF plate, Pin 6 is supplied with + supply for a brief time and as a result, the output of IC will become LOW.
This will turn off the transistor and deactivate the relay. As a result, the device will be switched OFF.

Applications of the touch lamp switch circuit

A simple touch to ON and Touch to OFF Switch Circuit can be used to control a simple LED without using any relay.
If we want to control the AC appliances, use a relay with this circuit.
You can use it for Ac Appliances control.

Touch On OFF control switch Circuit

We can use this simple touch lamp switch to control any home appliance. It is a very efficient and simple touch light switch. Only one thing must keep in mind if you want to control AC appliances then use a suitable relay. it is a magic touch lamp switch for fun or any hobbies.