We all have heard about clap switch in various science fairs and it seems to be very popular among students. Today, we will see how we can build one of our own. It is very easy and it will help you understand the concept of energy conversions via circuit and how by just using simple technology, we can build this. 

Introduction :

Clap Switch is also known as “Sound Operating Device”. It is the basic mini-project made up with
555 timer IC and some capacitors and resistors with an electric condenser mic.
Clap switch is generally used for switching the device “ON” or “OFF” by simply producing high-frequency sound. The most common way using clap, this is the reason it is called clap switch.

NOTE: Clap is just a medium, we can use any type of object which can generate High-frequency Sound


In this project, we have to convert sound energy into electrical wave. To do this, we use microphone but as microphone signal is weak, we use transistor to amplify it.  Than, we feed this amplified output to the Flip Flop circuit which gives reverse output with each trigger pulse, i.e our clap.

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Components required: 

Capacitor: 10uf and 100 uf ( 2 pcs.)

Resister :1k, 4.7k,47k, 330 ohm

One Electric Condensor Mic

Transistor: BC547 (2 pcs.)


One 555 Timer

One 9v Battery

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Working :

The Clap Switch circuit generally works on the principle of conversion of sound energy into Electrical Energy.

When one clap or generate the high-Frequency sound, the electric condenser mic absorbs the sound and converts the sound energy into electrical energy and then the electric pulse go to the transistor.

This circuit is mainly dependent on the transistor because negative terminal of the mic is directly connected with the transistor.

In this circuit, we give the sound input and it is changed into Electrical energy and LED turns ON and when again, we give Sound input, LED turns OFF.

1.Turn on the LED timer can be varied by changing the value of capacitors as it is connected with the 555 timer which is used to generate Electric Pulse.

2.Negative Point of the mic should be connected with the amplifier end otherwise the circuit will explode or blow up.


1.By doing simple Clapping, We can operate our home appliances Turn On or Turn Off.

2. We can use any electric or electronic devices in place of LED.

Application :

In Home, we can use this circuit to operate our light, fan or AC by simply making high-frequency sound i.e Clap. As this can be connected with our home equipments, we can use it on the place of any mechanical switch. The only disadvantage is that, you don’t want it to keep switching lights on and off on every high frequency sound. But they can be great assets for Discs and other party places.