Simple Clap Switch Circuit Using Transistors

In one of my earlier post we learned a simple clap switch circuit which incorporated an IC for implementing the desired flip flop actions. The present design uses a different principle and utilizes only transistors for the above triggering actions.

How the Circuit Functions

Looking at the circuit diagram we see that the entire circuit has been configured around ordinary general purpose transistors.

The functioning of the circuit may be understood with the following points:

Transformer X1 along with the D1 and the capacitor C4 forms the basic power supply circuit for providing the required power to the circuit.

The first stage which includes R1, C1, R2, R3, R4 and Q1 form the input sensor circuit.

The next corresponding stages consisting of Q2 and C3 form the flip flop stage and makes sure that the signals from the input sensor stage is appropriately converted into alternate toggling of the output.

The output stage consists of a single transistor Q4. It is basically configured as a relay driver stage for translating the flip flop actions from the previous stage into physical toggling of the connected load across the relay terminals.

The diagram of a simple clap switch circuit using transistors is shown in the below given diagram

Parts List

R1 - 15K

R2,5,12- 2m2

R R3 -270K

R4 - 3K3

R6 - 27K

R7,11 - IK5

R8,9 - 10K

R13 - 2K2

C3, C1 - 10KPF Disc

C2,3 - 47KPF Disc.:

C4 - 1000uF/16V;

Q1,2,3,4 - BC547B

D1 - 1N4007

D2,3,4,5 -1N4148 _

Xl - 12V/300mA Transformer .

MIC - Condenscr Mic

RLY — 12V Single Charge over relay

Another version of the above can be seen in the following diagram:

18 thoughts on “Simple Clap Switch Circuit Using Transistors

  1. Have questions? Please feel free to post them through comments! Comments will be moderated and solved ASAP.
  2. Hi Swagatam my name is Riyad.

    i would like to ask you if you could maybe help me with something. I am using an existing single clap switch circuit for a project design for University but i want to change the single clap operation to a double clap one using flip flops or something like that but not a microcontroller, but i have no idea how to incorporate that into my circuit. Could you help me please? My personal email is Thank You

    • Hi Riyad,

      I'll do it for you, but in return you will have to do me a favor.

      Write a min. 300 word post, in your own words about your above requirement and send it to me.

      You can stuff as many words as you like about your requirement, about your experience in the field, etc etc.

      i'll publish this data in the form of a new article and also provide the circuit diagram in it.

      You can send it to


    • The circuit was built by me a long time ago when I was in school, it had worked perfectly without any issues. Actually it's a Vega-kit project which I have produced here.

      Please check all the connections properly, the upper terminal of C3 connects with D3 and R12 only.

      R9 is connected across base of Q2 and the collector of Q3.

      Only the black dots indicate connections.


  3. Hi me Niladri..
    i am a fan of u….
    i want to make a clap switch which will operate on 220 ac line….
    pls hlp me…
    how can i connect this with main line to operate bulb tubes and other electronic apps.
    and pls sujjest me also which circuit will cost low as much as possible…

    • everything's correct in the shown diagrams, I have myself tested the first one and it worked at the first attempt, it would be difficult to troubleshoot your circuit without practically examining it.

    • you might have done something wrong in the connections.

      note that R7 and R11 upper ends are connecting only the positive line.

      Q3 base is connecting with only R8

      the crossing lines which are not shown with black dot are not connecting with each other

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