clap switch.

Very sensitive Clap operated ON OFF Switch

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Simple clap switch circuit diagram 220v using relay

High-Sensitive Clap operated switch circuit Without Microcontroller. When clapped, Connected Load is Switch ON.  Again Clap, the Load is switched OFF. A condenser mic is worked as a sound sensor.

You can Switch ON and Switch OFF The Appliance At your Room by simply clapping Or by a Sound.

This is Sound activated ON OFF Switch to ON or OFF any appliance.

This clap-operated ON-OFF Switch circuit is very sensitive and easily operated up to a distance of 5 Meters If the condenser MIC is fixed into a Special type of Cover to Receiving More Sound From a Maximum Distance. 

This Clap/Sound controlled ON-OFF Switch circuit consists of two ICs, two NPN transistors, One PNP Transistor and some other components. 

The LM358 is an opamp-comparator that has two Op-Amp in a single ic chip. This ic is dual operational Amplifier But in this circuit, one op-amp is used.


Connect All the required components as Given in the diagram. Enclose the condenser microphone to As possible as much maximum sound Reach easily to this. Use all the Resistors as given value for more sensitivity and set the preset by moving. You can use the 2N2222 Transistor as the place of 548. 2N2222 has fast switching Keep in mind to Condenser MIC has polarity, So if the circuit is not working then check the polarity of MIC. Pin Configuration of BC548 and BC558 is same. 

Sensitive Clap operated ON OFF Switch Circuit diagram

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IC 4017 is a decade counter which has 10 outputs, Outputs are ON one by one in sequence as Clock Input at pin 14 is changed. When once the Clock input is changed the output goes at next. When Again the clock input is changed at pin14 the output goes at the next output pin and so on. Pin-2 is output 1. It goes high when the counter reads 0 counts.

Pin-4 is output 2. It goes high when the counter reads 2 counts. 

Clock input change means the input of pin 14 is changed from Negative to Positive voltage supply Or Reversed. When Clock input is changed then the output of 4017 is changed From High to Low And Low to High. This Property is used in this project. 

IC 358 is Dual Opamp Comparator That Compares the input signals Level at inverting and noninverting input pins as Low or High signal value Levels in respect to both pins. This ic has two inputs, inverting and non-inverting. The inverting input is called Vref. The non-inverting input is called as Vin. The output of the comparator depends on the voltage level of these both input.

LM358 Pin
LM358 Pin configuration

When the voltage at Vin is more than Vref then output is 0v (-vcc)

When the voltage at Vin is Lower then Vref then output is High (+vcc)

LM358 opamp comparator PinAt first when Circuit is switched ON But not clapped, The condenser mic no detects any sound and at this condition, the resistance through this is Very high and The voltage level at pin 2 (Vref) is Very Less in comparison with Pin 3 (Vin). In this case, the output is 0.

When clap, the sound is detected by the condenser mic and the resistance between vcc and pin 2 is very less, and the voltage level get increases in comparison with the voltage level between vcc and pin3. In this case the Output is changed and it is now Turn Low to High . 

As the signal input at pin 14 of 4017 in changed as the output at pin 2 is changed from Low to High. Again When the input at pin 14 is changed, the output at pin 2 is changed from High to Low.

According to the output of pin 2 transistor Q3 is Turn ON and OFF and Relay Activate therefore the Appliance is ON OFF By clap.

This circuit is tested on 6v supply

BC557 Pin diagram 1






BC548 or 547-2

BC557 or 558-1


2.2uf 25v-1









Condenser MIC-1


Relay 6v -1


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