Thursday, December 22, 2011

Make a Simple Electronic Clap Switch Circuit

Want to build a simple clap switch circuit that will toggle any load in response to your claps? The article is meant exactly for the said purpose. A small sound activated switch circuit comprising a sound amplifier and a flip flop is presented here, which can be easily built and used to toggle any electrical gadget through hand claps.

The article is exactly about what the title suggests – a clap switch. A small electronic circuit when built and integrated to any electrical appliance can be made to switch ON/OFF through mere hand clapping. The entire procedure is explained here in.

You have seen magicians doing this, a “clap” and the object vanishes. Obviously I am not here to teach you magic, however the present circuit is nothing less than a magical device, well certainly can be for the children. The proposed design of a clap switch circuit when integrated to any of your electrical appliance can be used to switch it ON and OFF simply through alternate clapping of your hand. The device becomes more interesting and useful because it does require any external mechanism or device to carry out the specified operations.

As you must have noticed the clapping of hands creates a loud sound and is sharp enough to move quite a distance. The generated sound is in fact strong ripples or vibrations created due to the sudden compression of air in between our striking palms.
The circuit presented here is basically made up of two stages, the first stage is a two transistor hi-gain amplifier and the second stage consists of an efficient flip/flop. A mic is connected to the amplifier stage; the sound vibrations made by clapping hits the mic and get converted into tiny electrical vibrations. These electrical pulses are amplified to suitable levels by the transistors and are fed to the flip/flop. The flip/flop stage alternately switches the output relay driver in response to every subsequent clapping. The load connected to the relay thus also gets activated and deactivated correspondingly.

The circuit may be further understood with the following explanation.

Parts List

Analogue Clap Switch Parts List

R1,R4=2.2k
R2=1M
R3=220K
R5,R6,R7=1K
T1,T3=8050
T2= BC557
ALL DIODES=1N4148
IC1 = 4017
C1,C4 = 0.22uF
C3=10UF/25V
C2=1uf/25V
RELAY=12V/400 OHM
MIC=ELECTRET CONDENSOR MIC
GENERAL PURPOSE BOARD, SOCKETS, ENCLOSURE, FUSE HOLDER ETC

Circuit Description

The figure above shows a straight forward two stage sound activated switch.
The first stage comprising T1 and T2 forms a hi-gain voltage amplifier configuration. A mic is connected at the base of T1 via blocking capacitor C1.
Strong sound vibration hitting the mic is instantly picked and converted into tiny electrical pulses. These are in fact small AC pulses easily make there way through C1 into the base of T1. This creates a kind of push-pull effect and T1 also conducts in the corresponding way.
However the response of T1 is relatively weak and requires further amplification.
Transistor T2 is introduced exactly for this and helps to improve the voltage peaks created by T1 to appreciable levels (almost equal to the supply voltage.)
The above voltage pulse is now ready to be use for toggling the flip flop and is fed to the relevant stage.
IC 4017 as we all know produces sequential shifting of its output pin-outs (logic high) in response to every positive pulse at its clock input pin 14.
The amplified clap sound voltage pulse is applied to pin 14 of the above IC, this flips the output of the IC to either a logic high or a logic low depending upon the initial status of the relevant pin-out.
This triggered output is appropriately collected at the diode junctions abd used to toggle a relay through a relay driver transistor T4. The relay contacts of this clap switch ultimately goes to a load or an appliance which is correspondingly switched ON and OFF with every subsequent claps.


Another cool Clap Switch Circuit.


The above circuit of a simple clap switch was provided to me by one of the keen readers of this blog Mr. Dathan.

The circuit is very to understand:
The opamp here is configured as a comparator, meaning it is positioned to differentiate the slightest of voltage differences across its two inputs.
When the clap sound hits the mic, a momentary drop of voltage is experienced at pin#2 of the IC, this situation raises the voltage at pin#3 of the IC for that instant.
As we know, with pin#3 at higher potential than pin#2 makes the output of the IC high, the condition puts the output of the IC go high momentarily.
This high response triggers the IC 4017 pin#14, and forces its output to either move from pin#2 to pin#3 or vice versa depending upon the initial situation of the outputs.
The above action switches the load accordingly either to ON or OFF position.


The above clap switch circuit using IC 741 was successfully tried and tested by Mr. Ajay Dussa. The following prototype images for the same were sent by Mr. Ajay.











The PCB design (track layout) for the above can be seen below, as designed by Mr. Ajay:


103 comments:

  1. I have made the circuit but when i supply the voltage the led at load(Instead of relay) simply glowing.Nothing happens when i clapped it simply glows

    ReplyDelete
    Replies
    1. Make the below given circuit, it has been tested by me, first make it and check its response as explained in the article then I will explain you how to proceed...

      http://homemadecircuitsandschematics.blogspot.in/2012/04/simple-clap-operated-stairway-light.html

      Delete
    2. How can i increase the sensitivity of the mic.(I want to move my hands near to the mic and clap in loud noise).

      Delete
    3. I have redesigned the circuit as show in the link posted by you.But the sensitive of the mic is so low.How can i increase the sensitivity of the mic to the peak point.

      Delete
    4. When I tested the circuit, it could sense a clap sound even from a distance of 10 feet so I am not sure how it's not working for you.

      Did you use BC547B transistors at the input? The mic should be electret type condenser mic.

      You may try altering the 2k7 MIC resistor, check by increasing or reducing its value.

      Delete
    5. Hello sir,
      Can I incorporate a triac in this circuit instead of the relay? and how?
      Thanks.

      Delete
    6. Yes, it can be done. Connect the right hand side pin of the triac to R6, center pin to ground and the left pin to AC load.....the load's one wire should be connected to mains AC. The other point from the mains AC should be connected to the circuit's ground.

      The circuit will get linked with mains AC directly, so maintain extreme caution while working with it.

      Delete
    7. Thank you for the very quick reply.
      I have another question..is it safe for the circuit components to be exposed to the 230V side?

      Regardless of the answer,the reason for asking about triacs was that I'm looking to drive the circuit by a small 12V battery and was wondering is there a difference in current drawing for the two options.
      The AC load is too small (100mA)and will be on for couple of houres every day.

      Delete
    8. The circuit components won't be affected by the AC since only a single line will be floating in the circuit, however for us it will be very dangerous to touch.

      The battery will provide power to the circuit, while the AC will power the load, the two have no connection with each other so it's entirely safe.

      Delete
    9. do we have to use the same parts for the second one?

      Delete
  2. in this circuit, instead of using mic, if v use a tsop 1738 , will it work like clap switch for each clik on remote controller??

    ReplyDelete
  3. Replies
    1. will depend upon the relay contacts....

      Delete
  4. Replies
    1. not sure, did not check it practically.

      Delete
  5. Hi. thanks for making it so clear. but I still have a thing to ask about, how big is it ? because I want one that fits in 2*3 cm .

    ReplyDelete
    Replies
    1. Hi,

      Thanks!

      The relay itself would be 2*3 in size...you would require at least a 3 by 4 inches board for this to accommodate.

      Delete
  6. Sir,

    I made clap switch using IC555, but its flip-flop switch,means when clap just LED lid and off again, while I want to use this circuit with toy car so my purpose not solve. I got this circuit from http://www.minibread.org/wp-content/uploads/2012/04/basic-clap-switch.jpg.

    what modification I do, plz send circuit diagram.

    ReplyDelete
    Replies
    1. I accidentally deleted your reply, please post it again.

      Delete
  7. You will have to incorporate the above article's flip/flop section with the 555 IC output....eliminate everything that's on the left side of the IC4017 and connect the output pin#3 of 555 to pin#14 of the IC4017 given in the above article.

    ReplyDelete
  8. Sir,
    I want to use this circuit with DC motor(3-9v DC, toy car motor), should I directly connect Dc motor with IC output(only remove R6,T3,relay and others)?

    if I use IR IC (TSOP 1738) with pin 14. it will work with TV remote?

    Pin configuration of TSOP 1738: pin 1: Ground(-ve); pin 2(vi): +ve with reg(47R); pin 3(vo): connect to IC pin 14 via capacitor(0.01uf).

    M I right sir?

    ReplyDelete
    Replies
    1. Akhilesh, these will not work.

      however you can remove the relay and connect the motor in place of the relay, keep the diode across the motor.

      Sensor at pin#14 will not work, you will have to incorporate your 555 circuit as suggested earlier by me.

      Delete
    2. ....use TIP122 in place of T3 if you are connecting the motor as suggested above..

      Delete
  9. Sir,
    I am planning to make this circuit, because dont have more space to add big circuit. ur circuit is clap-on/clap-off ( need clap to on and clap to off)?

    How can I increase the mic sensitivity to use by children?

    ReplyDelete
    Replies
    1. You can make this circuit and connect the collector of BC557 with pin#14.

      http://homemadecircuitsandschematics.blogspot.in/2012/04/simple-clap-operated-stairway-light.html

      Yes the above circuit has a clapOn/clap OFF feature.

      Delete
  10. there is a confusion in ur circuit at C2, not define +/- of capacitor, hope +ve of capacitor is connected with T1.

    ReplyDelete
  11. hello sir,

    I have a question about the Mic:

    -What is the voltage of the MIC?



    ReplyDelete
    Replies
    1. It is an electret MIC, not sure about the specs...

      Delete
    2. will this one work?

      http://www.conrad.com/ce/en/product/710795/KEPO-KPCM-G60H50P-44DB-1185-microphone-capsule-22-k-15--6-mm-x-5-mm/0235010&ref=list

      Delete
    3. i need data sheet on this project.

      Delete
  12. hello

    What is the T1 transistor ? Please give me more information about it. Please

    ReplyDelete
  13. you have not mentioned the polarity of the C2. please do mention it and also can the 63v capacitor work instead of 25v in C1 C2 C3

    ReplyDelete
    Replies
    1. C2 positive is towards R5. 63V capacitor will work.

      But this circuit has not been tested practically.

      Delete
  14. what will this designs power consumption be like once acivated ?

    ReplyDelete
    Replies
    1. around 50mA while the relay is ON, and 5mA otherwise.

      Delete
  15. sir, i kudnt get an electrate mic in my locality. Can i use a speaker in place of a mic?

    ReplyDelete
  16. Hello Sir, Can I use audio signal ( such as as mobile message or missed call ) place of the microphone?

    ReplyDelete
    Replies
    1. Hello khairul,

      how do you want to connect the audio output of the cell phone?? through a wire??

      Delete
  17. What is the advantages and disadvantages for this kind of circuit??

    ReplyDelete
  18. Hello Satyam can you help me design a PIR sensor based or microwave sensor based circuit with which i can operate the light source at full power when someone is in the range of that sensor and at 20% power only when no one is there in the range of the sensor??

    ReplyDelete
    Replies
    1. Hello KKaranjia

      Please provide a detailed description of the whole concept, it would help me to design the circuit more easily and correctly.

      Delete
    2. hii satyam i didn't get any feed back from your side after my last post so kindly tell that is the circuit possible which i am asking for??/

      Delete
    3. though I am not sure who is Satyam here, I have replied to all your previous comments, please check them out.

      Delete
    4. sorry by mistake i typed wrong name.

      Delete
  19. Swagatam what i want is that when any person is present in the vicinity of the light source the light source should glow at its full intensity consuming 100% power and when the person walks away form the vicinity of the light source the light source show dim down to 20% of its capacity thus consuming only 20% power and mostly the light source will be LED type. This circuit might help to save power in places like parking lights and common areas of commercial buildings

    ReplyDelete
    Replies
    1. Hi KKaranjia,

      I think I already have a couple of such circuits posted in this blog:

      http://homemadecircuitsandschematics.blogspot.in/2013/03/energy-saving-intelligent-automatic-led.html

      http://homemadecircuitsandschematics.blogspot.in/2012/09/pir-controlled-led-driver-circuit.html

      Delete
  20. Dear Swagatam in your circuits the light source gets completely switched off when there is no human in the vicinity and due to LDR the brightness of the light source increases or decreases as per the surrounding light but what i need is theat the light source should work at 20% power when there is no human in the vicinity and when human presence is sensed the light source works at 100% and the brightness of the light source need not be increased or decreased as per the surrounding so there is no need of LDR.

    ReplyDelete
    Replies
    1. Dear Kkaranjia,

      Refer to the second circuit in the following article:

      http://homemadecircuitsandschematics.blogspot.in/2012/10/how-to-understand-and-connect-passive.html

      wire the relay in the following manner:

      connect the N/C to (+) supply via a calculated high value resistor.
      connect the N/O to (+) supply via a calculated low value resistor.
      connect the pole of the relay to LED (+) line, connect the negative line of LED to negative of supply.

      The high value resistor must be calculated to produce 20% light while the low value resistor to produce 100% light.

      Delete
  21. Dear Swagatam,

    Can You help me with RF receiver transmitter circuit which is compatible HT640 and HT648L. And I don't want the readymade circuit which is available, I want to make my own so please provide circuit if possible.

    ReplyDelete
  22. sir i am new one to this...will it work sir ?
    did u check it sir ?

    ReplyDelete
  23. Dear Swagatam I am in need of RF receiver transmitter circuit compatible with HT640 and HT648L. I want to make the circuit on my own so dont want the readymade available in market

    ReplyDelete
    Replies
    1. Dear kkaranjia,

      you may refer to the following article, the basic principle will be the same as explained here, just the pinout configuration will be different for your ICs:

      http://homemadecircuitsandschematics.blogspot.in/2013/07/simple-100-meter-rf-module-remote.html

      Delete
    2. Dear Swagatam

      I already know about this readymade RX-433 and TX-433 but i want to make circuits on my own so don't want to use this readymade ones. can we use the receiver transmitter circuit that is used with TX-2b and RX-2b???

      Delete
    3. Dear kkaranjia,

      Yes, it can be used but what will you insert in the RF stages.

      Delete
    4. I didnt get your point. I want to make circuit 8 chanel transmission so i am using ht640 and ht648l for this purpose. its just for remotely controlling 4 motors. i am planing to use two L293d at the output bits of ht648l

      Delete
    5. I responded to your previous comment where you mentioned TX2b and Rx2b chips. These chips require RF stages for operating an RC model

      Delete
    6. Dear Swagatam you asked that what will i insert in RF stage so didnt get this question of yours and i have circuit regarding this rf stage can u help me evaluate it, if yes then i can sent you the images on your email id.

      Delete
    7. Dear kkaranjia,

      I was referring to the following circuits:

      http://datasheet.eeworld.com.cn/pdf/SILAN/153017_RX-2B.pdf

      anyway you can send it to my email ID.

      Delete
  24. Dear Swagatam

    I know of this circuit and i want to the rf portion form this circuits and incorporate it with HT640 and HT648l so can i do that and if possible then what changes have to be made in the circuit???

    ReplyDelete
    Replies
    1. Dear kkaranjia,

      If you are intending to use the circuit which is given in the above mentioned datasheet then you will have to incorporate the RF modules shown in the first image of this article. HT640/648 cannot be used as they are en/decoders, not RF chips.

      http://homemadecircuitsandschematics.blogspot.in/2013/07/simple-100-meter-rf-module-remote.html

      Delete
  25. Dear Swagatam i will be sending you a circuit diagram in mail. kindly verify and tell weather it can work properly or not??

    ReplyDelete
  26. hi my name is jaco.
    i have a electronic project where im required to build a clap switch using the following componets:
    33 k ohm 1/4 W 5%
    1 M ohm 1/4 W 5%
    5 K 6 ohm 1/4 W 5%
    270 ohm 1/4 W 5%
    47 k ohm 1/4 W 5%
    BC 547
    100 uF 16 volt redail
    10 uF 16 volt redail
    1 uF 16 volt redail
    1N4148 diode
    5mm LED (red or green)
    electret microphone
    6 V DC PSU
    could yo please explain how to connect the circuit. this is my first time.
    thanks.
    Jaco

    ReplyDelete
    Replies
    1. Jaco,

      you can refer to the following circuits, it closely matches your application:

      http://homemadecircuitsandschematics.blogspot.in/2012/04/simple-clap-switch-circuit-using-only.html

      Delete
  27. In the above article "Make a Simple Electronic Clap Switch Circuit", only one 230V supply line will pass through the circuit, right? And the other will directly go to the load?
    If yes, where do I exactly connect the two wires in the circuit, the first one coming from the supply line and the second one going to the load ( I can't understand that from the diagram)
    As I am an amateur, any help will be greatly appreciated.

    ReplyDelete
    Replies
    1. It's correct, one of the AC mains line will go to pole of the relay, while one of the load wires will go to the N/O contacts of the relay, you may refer to the following article for knowing more about relays:

      http://homemadecircuitsandschematics.blogspot.in/2012/01/how-to-understand-and-use-relay-in.html

      Delete
    2. Thanks! and I have one more doubt- according to the diagram given at the end of the article on this page- http://homemadecircuitsandschematics.blogspot.in/2012/01/how-to-understand-and-use-relay-in.html
      I have to connect the coil terminals in the DC circuit (which we are making), and one of the AC mains to the middle pin i.e. movable contact and the load line to the N/O terminal, right?

      Delete
  28. Hi, I am making a circuit for the first time, so can you let me know whether this one is tested, it will surely work, right?

    ReplyDelete
    Replies
    1. You can try the second circuit, it has more chances of succeeding, although both are untested.

      Delete
  29. Sir! I wonder one point sir..does this circuit active only with clap sound? And about other sound like speech sound? What happen when there are alot sound in that place?

    ReplyDelete
    Replies
    1. any loud sound will activate this device....it's more of a toy than a genuine switching device.

      Delete
  30. I try to replace with 1uf to 10uf, but it is still the same.

    ReplyDelete
  31. Hi, I am doing this for a project in my electronics class at school I have breadboarded the circuit exactly as above but nothing happens when I clap. I replaced the microphone with a switch to test also but that didn't work either. Can you please help me find the problem?

    ReplyDelete
    Replies
    1. which circuit did you make? Try the second one, it will surely work according to me.

      Delete
    2. Sorry, the first one worked fine it was my fault I was using a polarised capacitor for C2 :S

      Delete
  32. Sir.! I want to make a circuit about voice interrupt music..this circuit consists of two input, audio input and mic, and one output to amplifier. First, the input from any audio player. While playing, if their is any sound into microphone, audio will become mute. After the sound from microphone is stop, the audio will be increasing its volume rapidly to its initial volume for some seconds. So, can you guide me some sir?

    ReplyDelete
    Replies
    1. Hi Seok,

      I'll try to design it soon and inform you , also let me know where and how you are going to use this circuit?

      Delete
  33. what is the output of the relay in the second circuit?

    ReplyDelete
  34. below circuit published by u does not work when i clap nothing happens i have checked my all connections twice only the red LED glows

    ReplyDelete
  35. Please, I have no access to IC741. Can I connect the amplification stage of diagram 1 to the 4017 flip flop configuration of diagram 2....... Merry xmas

    ReplyDelete
  36. I have assembled the board for an extra credit project for an engineering physics class however it is not working. When I connect power to the circuit I'm getting a random array of lights either one or two and clapping has no effect on the system, any ideas what could have caused this? I have checked and rechecked and the diagram has a few mislabeled items such as two R5's and no R3. Please help me thank you very much.

    ReplyDelete
    Replies
    1. The circuit could need some fine tuning and tweaking before it produces the intended results.

      You can try the following few thing's:
      decrease R1 to 2.2k or to any smaller value
      remove C3 from its shown position and place it in parallel to the collector resistor of the BC557,
      use BC547 for T1.

      I'll correct the mislabeled pats quickly...

      By the way there are no lights in the circuit??

      Delete
  37. dear sir,
    i m a student. my teacher has gave me this model
    will u please give a easy stepwise note that how can i make this.........
    plzzzz sir......

    ReplyDelete
  38. hello sir i want 2 make a clap switch for my requirement but how can i use it for a dc supply.what changes to be made for the above circuit to use it in dc supply. i will thank full to u if u suggest me

    ReplyDelete
    Replies
    1. hello Harish, what is the DC load that you intend to connect?

      Delete
    2. Harish, you can use a standard 12V, or 9V AC/DC adapter for powering the circuit, even a mobile charger will work if a 5V relay is used, no changes would be required.

      Delete
  39. i dnt knw hw to connect the relay in the circuit can u pls help me

    ReplyDelete
  40. hello sir,
    I make second circuit as shown by the circuit diagram, only Red LED glow. I didn't understand the reason.
    Is there any specification of mic.
    Plz help me im very thankful to u

    ReplyDelete
    Replies
    1. Hello Mahesh,
      connect another led in series with R4, now adjust the preset carefully until it just shuts off...now clap in front of the MIC, the circuit should respond as proposed, and this LEd will momentarily flash and again shut off.

      Delete

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Readers are advised to proceed with the construction of the presented circuits only after understanding the concepts from the core. Not adhering to this can lead to failures and frustrations.