Clap Switch : Circuit and Its Working

An electronic device that can turn off by clapping is called a clap switch. It can control light appliances by users' clap action also. It was invented by Stevens, R Carlile, and E Dale Reamer in 1996. The main advantage of this circuit or device is that it is mainly helpful for a mobility-impaired person. The condenser mic is one of the main parts of the circuit that takes input clap sound based on the pitch of the clap. This article gives an overview of the clap switch. Electrical pulses are the desired input to the clap switch circuit.

What is Clap Switch

Definition: A clap switch is an electronic circuit or device that controls electrical appliances like tube lights, energy savers, and LED bulbs,s, etc with user clapping action. It is mainly useful for a person who cannot move from one place to other for switching on or off electrical or electronic appliances. Clap switch circuits can be designed in a variety of ways nowadays electronics students are designing these circuits by using decade counter ic 4017.

Circuit switch Circuit Diagram

This is a very simple circuit you can change its design according to your requirements.

Circuit switch Circuit Diagram

These sound vibrations are given to the Base point of transistor BC 557 (a PNP transistor). It amplifies the sound collected by the Mic. The transistor collector point is connected with IC point 14 which is the clock point. When clock e is received from Amplifier Transistor BC557.
IC 4017 is a decade counter IC that is wired as a toggle switch. That its outputs 1 and 2 become high and low when the input pin 14 receives pulses.  output4 (pin4) is connected to the reset pin 15 so that further counting is restricted. The high output from IC 4017 passes through a resistor to the base of the switching transistor BC557. When BC557 conducts, Red LED (indicator LED) turns on.  A 6V 100 ohms relay is connected to the points marked (A and B), the relay is turned on and 220v AC pass through the relay and the bulb or any other electrical appliance is Switched on. In the next clap output pin, 2 becomes low and the relay and indicator LED are switched off.

PART LIST For Clap switch circuit

  •  Prototyping board (Roughly 1″ by 1″) or breadboard.
  • 9v connector
  • BC 547 transistor (NPN)
  • BC 557 Transistor (PNP)
  • IC 4017
  • 22k resistor
  • 470-ohm resistor
  • 1k resistor
  • 6v relay
  • 9v battery


The following are the advantages of clap switch

  • It is a reliable and low-cost circuit
  • It is an advantageous technology for mobility-impaired person
  • Automatically controls lights within a specified range by clapping action
  • It provides good output efficiency and can control high loads.


The following are the disadvantages of clap switch

  • The filter should be added to the circuit compulsorily for work.
  • It is cumbersome compared to traditional control switches and it can be operated even by an unknown person.


The following are the applications of the clap switch

  • to on or off LED light
  • Air conditions
  • Tv
  • Motor, etc.


1). Who invented the clap switch?

The main fonder of this idea and the circuit was R Carlile, Stevens.

2). When it was invented

The first clap switch circuit was invented on Feb 1996

3). Name two main applications of Clap Switch?

The two main applications are

  • LED light
  • Fans

4). Is the Clapper a fire hazard?

No, the Clapper is not a fire hazard its saves

5). What is the main principle of a clap switch?

The clap switch converts sound energy into electrical pulses as input to the circuit and provides an output in order to control light appliances.

6). Can it work by all people claps

yes normaly it can operate by the claps of all persons but you can specify it's working like it will work with 2 or 3 claps or turned off by 2 or more than 2 claps.