Sound Activated Switch

This is a sound activated switch circuit. It’s will turn on and turn off based on a loud sound such as clapping your hands. You can adjust the sensitivity (how loud of a sound will activate the circuit) from a pin drop to a Mack Truck Horn. Very practical for a variety of projects. Add a relay to turn on a light when your dog barks, or set of a siren when an intruder makes a loud noise.

Here the circuit diagram:

Sound Activated Switch circuit diagram

This circuit operates on 9 VDC battery or you may use a DC power supply instead of a battery. Electret microphone used to catch the sound (very sensitive). The sensitivity can be adjusted via potentiometer.

Components List:

R1, R5, R16 = 10k?
R3 = 22k?
R2, R6, R9, R13 = 220k?
R4, R10, R12, R14 = 100k?
R7 = 270k?
R8 = 4.7M?
R11 = 1M?
R15 = 330k?
R17 = 4.7k?
P1 100k? Trim Pot
C1, C3 = 10nF
C2, C4 = 100nF
C5, C6, C8, C9 = 1nF
C7 = 1uF/16V Electrolytic
C10 = 100uF/16V Electrolytic
Q1 = 2N3904
Q2 = MPS6531
U2 = 4001 Integrated Circuit
U1 4011 Integrated Circuit
MIC = Electret Microphone

PCB Layout:

Sound Activated Switch pcb design

Download the manual instruction for this sound activated switch circuit:

This circuit kit available at, go to that page to buy the kit.

Incoming Search: simple sound detector circuit, voice activated switch circuit diagram, audio activated relay circuit

8 thoughts on “Sound Activated Switch

  1. Ratnadeep

    Sir,,Is there any circuit diagram u know..that can turns the house light on when c clap sound is appears n remains constant..n also turns d light off with any sound or a clap..If u know about dis then plezz make for me circuit diagram for me..N send it to my e-mail d…plezzzzz sir

  2. surya

    i would like to enhance some of its characteristics by installing voice regonisition and multi voice commands to activate light , fan ,ac etc.i would like to have some suggestions and propose circuit . iwill be highly thakful for ur help!!!!!!!!!!!!!

  3. blingzy

    i want to do the clap activated switch but i donk know the procedure .!
    pls .help for my project .. thanksx .!

  4. gino palay

    Is there other substitute transistor for Q2? because MPS6531 is not available here…

  5. adnanuddin

    this circuit has a problem as you can’t use any tv or audio system which may trigger the circuit. i was looking for voice controled triggering circuit

  6. timoi

    in what website i can find in how to make a sound activated switch?

  7. Cris Thinks

    I want to build this Sound Activated Switch but I need to understand its operation. Please send to me more information about this circuit. Thank You!

  8. Phillip Crosbyh

    The diagram is too fuzzy for me to read properly.I would really like to try to build this sound switch.

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