In order to make a clap switch, we have to combine the  touch sensor(monostable mode of 555 and the transistorized dark sensor circuits. Whenever there is loud sound produced near the electret condenser mic, pin 2 of 555 gets triggered and it switches on the LED D1. The LED remains on for a definite time determined by R1 and C1. We can adjust the sensitivity of the circuit using a variable resistor in place of fixed resistor R5. You can check the circuit with 1K or 10K.

The schematic of clap switch:

You can purchase this kit at BuildCircuit

You can see the steps for making a clap switch on the video given below.

Please check the following video tutorial

If you want to glow a bulb operating at 220V, use the following schematic:

clap switch operating 220V bulb

Before you make this project, read carefully about RELAYS: http://www.buildcircuit.com/how-to-use-a-relay/ If you are not confident at making circuits, don’t work with 220V, it can be dangerous and harm you.

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BuildCircuit is now selling a fully assembled clap switch that can operate 220V lamps. The first clap keeps the lamp on and the second clap keeps it off.