Want to build a simple clap switch circuit that will toggle any load in response to your claps? The article is presented exactly for this purpose. Here we discuss 4 unique and simple designs which can be selected as per user preference.
Overview
The article talks 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 not 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.
1) Clap Switch Circuit using IC 741.
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 12V clap triggered 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:
2) Using Transistors or BJTs
In the above explanations we learned a simple clap activated 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.
Video Demonstration
Parts List
R1 = 5k6
R2 = 47k
R3 = 3M3
R4 = 33K
R5 = 330 OHMS
R6 = 2K2
R7 = 10K
R8 = 1K
R9, R10 = 10K
C1, C4 = 0.22uF
C2 = 1uF/25V
C3 = 10uF/25V
T1, T2, T4 = BC547
T3 = BC557
All IC diodes = 1N4148
Relay diode = 1N4007
IC = 4017
Relay = 12v / 400 ohms
How it Works
The figure above shows a straight forward two stage sound activated switch.
The first stage comprising T1, T2, and T3 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.
Transistors T2/T3 are introduced exactly for this and help 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.
Clap Switch Circuit using BJTs and Power Supply
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:
3) Double Clap-Clap Switch Circuit
All the clap on switch circuits explained above have the ability to operate only with single alternate clap sounds. This feature makes the circuit vulnerable to external sounds which might occur occasionally triggering the connected load with the circuit.
A double clap operated circuit thus becomes more suitable and resistant to spurious triggering due to the fact that it would toggle only in response to two subsequent clap sounds instead of one.
The explained circuit is simple yet effective and does not employ microntrollers for the implementation unlike other circuits on the net.
The circuit has been tested by me, but it is a fairly complex design it's important to first understand the stages convincingly, and then build it to avoid failures.
Simulation and Working
The proposed clap-clap circuit or double clap circuit functioning may be understood with the following points:
The lower stage is basically a simple sound activated switch circuit which would activate with any loud sound.
The IC 741 is rigged like a comparator with its pin#2 referenced at some optimal fixed potential determined by the setting of the given preset VR1.
Pin#3 of the IC becomes the sensing input of the IC and is connected with a sensitive mic.
The adjoining IC 4017 is a flip flop stage which activates the connected relay driver stage and the load alternately in response to every positive high pulse at its pin#14.
When a loud sound such as a "clap" hits the mic, it momentarily grounds pin#2 of the IC741 resulting in a momentary high pulse at its pin#6.
If we connected this output to pin#14 of IC4017 would have resulted in an instant toggling of the load with every single sound input which we don't want here to happen, therefore the response at pin#6 of IC741 is broken and diverted to an IC 555 monostable stage.
How IC 555 is Configured
The IC 555 circuit is rigged in such a way that when its pin#2 is grounded, its output pin#3 becomes momentarily high for some period of time depending upon the values of the 10uF capacitor.
When a sound hits the mic, the high pulse from IC741 output triggers the BC547 attached to pin2 of IC555 which momentarily grounds pin#2 of IC555, which in turn put its pin#3 high.
However the instantaneous high at pin#3 of IC555 takes a while to reach the connected BC547 due to the presence of the 33uF capacitor.
By the time the 33uF charges and switches ON the transistor, the potential at the collector of the transistor is already gone due the absence of the clap sound which happens only momentarily.
However with the application of the immediate subsequent clap provides the required potential at the collector of the transistor which is now allowed to the reach pin#14 of the flip flop IC 4017.
Once this happens the relay driver triggers or deactivates depending upon its initial condition.
The toggling of the load thus takes place only in response to a pair of clap of sounds making the circuit reasonably foolpoof.
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vishnu says
hai Iam vishnu, sir I bulid a clap circuit using Bc547transistors without any Ic their are 3 transistor of Bc 547 and1transistor BAc368 without relay my circuit is completely worked first after some type it is not detect sound instead when we touch mic the LED wil ON&OFF .
Swag says
Vishnu, if you have built it on a breadboard then possibly there could be a loose contact somewhere, otherwise one of your transistors could have gone bad…BC547 are rated at minimum 60V so those may be fine but BC368 is rated at 20V only so may be you could test this transistor….and if you are using a relay make sure to use a freewheeling diode across the relay coil
Yanniverse says
I tried doing this project in breadboard but it doesn’t respond to my clap or any sound i made. the LED only lit, that’s it. what can be the possible problem in this one? I hope i could get a quick response, it is for our electronics project. Thank you and good day!
Swag says
first of all recheck all the connections, because breadboard are always prone to mistakes and loose connections.
if possible remake it on a veroboard by practical soldering.
If you are referring to the last circuit, remember the preset has to be adjusted carefully to get the results, otherwise the circuit won’t respond.
for testing the IC 741 response, remove the LED/resistor from the IC 4017 pin#3 and connect it across pin#6/ground of the IC 741.
Now after careful adjustment of the preset you should be able to see this LED becoming momentarily ON on each clap sounds.
aiwin anil says
YES IT WORKED,after a long time.Thank u for your instant reply.It is only because of your fast reply i could make it successfully.Now i have to make another project-amplifier circuit.Please suggest any website for this project which uses an ic,condenser mic and a 8ohm speaker(or any small speaker).
Swagatam says
I am glad to know it worked…congrats on that!
for MIC amplifier you can try the last diagram as given in the following article
https://homemade-circuits.com/2012/08/ic-lm-386-datasheet-explained-in-simple.html
aiwin anil says
I made it but when i connect the power supply,8050transistor near the diodes is getting heated and the circuit is not working.Please tell me where is the problem in my circuit.I have used the first circuit.
Swagatam says
In the first circuit it's BC547 near the relay, anyway even if 8050 is used it should not become hot…unless the relay coil is shorted, or you have done something seriously wrong with the connections.
make sure you have connected the transistor pinouts correctly.
daktei says
Can i power the second circuit with a 12v supply?
Swagatam says
yes you can
aiwin anil says
If i connect the relay to an appliance and clap will the applianceremain turned on untill i clap again.
Thanks in regards.
Swagatam says
yes, the appliance will remain switched in the same position until the next clap is made….
aiwin anil says
For the first circuit or second or will both the circuits work in the same way as you have replied above.
Thanks in advance.
Swagatam says
yes that's right, because both have flip flop stage…
Prashant Medhekar says
sir, as u said to connect 10k at pin 4 n 15 of ic 4017 and capacitor to pin 15 and +vcc .
the circuit work correctly as led at pin no 3 of ic 4017 glow before clap and after clap the led connected to transistor glow, but this happen only one time, after that circuit stop working none of led glow, now what should i do?
Swagatam says
Prashant, you can try putting a resistor 10K in series between pin#6 of IC 741 and pin#14 of IC4017, and connect a 1uF/25V capacitor across pin#14 and ground.
also for better reliability configure the output of the 4017 exactly as done in the first diagram.
Prashant Medhekar says
can can u tell me the exact value of pot for perfect result?
Terminator says
Sir can you tell me that we can use this circuit to automatically open the door??
Terminator says
Sir can you tell me that can we use this circuit to automatically open and close the door??? Please reply as soon as possible.
If yes then how?? What changes should be made in the circuit??? I have to submit a project proposal and my project is "automatic door opening using clap switch" and the circuit should work from the minimum distance of 8 feet.
Please help me…!!!!
The door is not of the full size. There is a mechanical model of wood of almost 1 feet tall.
Prashant Medhekar says
sir, when i apply 9v to the circuit which led sholud glow by default i.e.before clap, the one which is connected to pin no3 of ic 4017 or the led connected to transistor
Swagatam says
pin#3 LED should light up… but sometimes it might not because the logic high might disappear across one of the other outputs of the IC 4017….so to prevent this please connect a 10K resistor between pin#15 and pin#4…and also connect a 0.22uF capacitor from pin#15 to the positive rail.
manjunath says
sir any minor changes can made to second circuit that lead to more sensitive and responce small sound genarated by clap. now I was still struggling to adjust 1k preset as you said above. thanks
Swagatam says
you can try connecting a small value capacitor across pin6 ans pin3….this should improve the sensitivity of the circuit manyfolds
still the 1K perset adjustment will be crucial.
manjunath says
sir small value capacitor means which capacitor can i use and does it has polarity
Swagatam says
preferably it should be non-polar…you can try a 0.22uF, or a 0.33uF etc
manjunath says
sir i bought 0.22uf capacitor but it has polarity then which side to connect #pin 3 and #pin 6 ( #pin 3 positive and #pin 6 negetive . may i correct)
and was this 0.22uf capacitor to connect IC 741
thanks
Swagatam says
Manjunath, you can connect positive to pin6 and negative to pin3, but a non-polar would have worked better…I thought you would bring a ceramic disc type capacitor.
manjunath says
sir sorry to say that, i connected non-polar 0.22uf to the ic741 . but it was still not working perfectly even though i adujust 1k . which stage may be faulty as per your knowladge thank you very much sir
Swagatam says
can't say exactly, your MIC could be faulty or assembled with wrong polarity or the IC may be faulty or with wrong connections…
when you clap the MIC grounds the pin2 of the IC momentarily which causes the pin3 and pin6 to go high, this the basic working principle of the circuit, you can confirm whether this is happening or not.
manjunath says
SIR I MADE THE SECOND CIRCUIT BUT SEEMS IT WAS NOT SENSING ACCURETLY. AS YOU SAID IT WAS NOT SENSING ABOUT 10 FEET DISTENCE .I SHOULD TOO NEAR TO THE MIC ,THAT ALSO NOT SENSING PROPERLY.
WAS THE FIRST CIRCUIT WAS MORE ACCURATE THAN THE SECOND PLEASE HELP ME
THANKS
Swagatam says
Manjunath, you will need to adjust the 1K preset precisely for getting a proper response from the cirucit.
Initially, make sure the output of the IC just merely turns "low" (0V), by adjusting the 1K preset.
Thia will set-up the circuit optimally and claps from a little distance will also become responsive
this circuit is better than the first one.
manjunath says
Sir in second diagram where to connect VR1 as it contains 3 pins (the printed side facing us right side pin is negative, center pin is out, and right side is positive.) as per your diagram two pins are connected. Please help regarding this thank you.
Swagatam says
Manjunath, VR1 here should be a preset not a pot, and by the way presets and pots do not have polarity, so the orientation is not critical.
you can use the center pin and any one of the outer pins, and leave the other pin free (unused)
Prashant Medhekar says
hey what different thing can we use instead of led??
and use of relay is complusory??
Swagatam says
LED is used for indicating the clap response, it cannot e replaced by anyuthing else.
the relay is for switching a load ON/OFF in response to the claps…
Shirish Srivastava says
Hi swagatam ,I made a clap switch it's different from what you have posted here but works the same way. I want to Decrease it's sensitivity to make it a bit practical.
I was wondering if I could add a pot in series with the mic,will it help ?
Swagatam says
Hi Shirish, yes you can put a pot or a preset in series with "R1" and adjust it appropriately for the required level of sensitivity.
Unknown says
I did and did not work the first circuit.
Can you give me an idea of what is not.
Swagatam says
you can try the second opamp circuit or the one which is shown in the following article:
https://homemade-circuits.com/2012/04/simple-clap-switch-circuit-using-only.html
Anirudh Bhat says
Dear sir,
I tried out the clap switch which turns on for two claps as suggested by you. But it is not working. Could you please tell me what's the problem?
Swagatam says
Dear Anirudh, I'll try to update the article with a new easier one soon, you can try that once it's posted
rolando jumaoas says
why the collector in transistor is in the ground in the pcb layout?
Swagatam says
It is a "component side view" layout
Anirudh Bhat says
Sir, could you please tell me how to design a clap switch which turns on for 2 claps and turns off for one clap?
Swagatam says
Anirudh, I have the circuit posted in the following article:
https://homemade-circuits.com/2013/04/clap-clap-switch-circuit-double-clap.html
but it will switch off also with two claps
Anirudh Bhat says
Thanks a lot for your time and help sir.
If it's not a problem could you please tell me how to turn it off for a single clap?
Thank you again sir.
Swagatam says
Anirudhs, the linked circuit is designed to work with two claps (ON/OFF), to make it operate with a single clap switch-OFF will require a complete change in the configuration and will make the design much complex….so it is not advisable to do so, moreover a single clap will make the design vulnerable to ambient noise.
lorenz pango says
Hello, I would like to use this circuit as a school project (toy car) using a 9v battery. How do I exactly do that and also, I already bought all the parts and a 9V motor and a 9V battery
Swagatam says
Hi, you can try the IC 741 circuit, however it'll need to be tweaked appropriately for getting the most optimal results
Affaizal Faiz says
Hey, iam from indonesian, i want to ask question, look over the PCB according to the first pat sensor circuit or the second ? ( clap simple switch that was given to me by one of the readers of this blog Mr. Dathan sharp . )
Swagatam says
the PCB design is for the second circuit…
harishvar akaash says
Hello Mr.Swagatam ……I have a minor problem…i made mr.ajay's circuit….but the problem is the sensitivity of the mic….the sensitivity of the mic is very low…it doesn't even responds from 0.5 feet…plzz tell how could i increase the range of mic to the extreme level….. i will be thankful for your quick reply…
Swagatam says
hello harishwar, try a 10k preset in place of the shown 1K, and adjust it carefully to achieve the required sensitivity….hopefully this should solve the issue, other wise we may have to seek other options.
harishvar akaash says
hello Mr. Swagatam Majumdar……
plzz sort out my problem as soon as possible…..
i made mr.ajay's circuit …it works perfectly but the main problem is the sensitivity of the mic….plzz tell how can i increase the range of mic to the extreme level…. i need the mic to work at least at the range of 5m….if its not possible…what is the maximum range of the mic….waht modifications should i do in the circuit…. plzz reply
Kristian Tot says
you mean i should make the first schematic?
Swagatam says
no, not the whole circuit, replicate only the diode section which are connected to pins 2,7,1,6,11 of the IC4017, make sure that now pin15 is connected to ground.
Kristian Tot says
Just finised that but now not even the rel led doesen't turn on
Swagatam says
connect one LED in series with R4 also and check its response, if this LEd lights up very brightly will ensure a proper functioning of the 741 section….then you can only replace the 4017 IC and recheck.
Kristian Tot says
nope it doesen't work. i mean the relay doesent turn on. However i measure the voltage between the colector and the postivie voltage supply and it;s about 3V volt's.
Swagatam says
it means your IC 4017 is not responding, may be it's faulty, put diodes at the output of the 4017 as shown in the first diagram and do the connections accordingly for the relay and the transistor also…..try it before discarding the IC.
Kristian Tot says
I have made the circuit but my led's just blink when i clap. Could that be the foult of the CD4017 chip?
Swagatam says
yes it could be, before concluding do a modification, connect a 10uF capacitor parallel with R4 and check again.
Kristian Tot says
I don't have a 10uF capacitor and the stores are all closed for the next few days, will a 22uF work?
Swagatam says
22uF will also work, you can use it.
Kristian Tot says
Iave placed the capacitor and it it's working better but not like it's suposed to. Sometimes it just starts to blink and it doesen't stop and when i place the relay it just turns off. I have relapced the cd4017 chip with another and insead of a pot i used a 1kohm resistor which i now replaced with a 470ohm resistor and now it's just worse.
Swagatam says
the pot is required so that the sensitivity and optimal working from the IC741 can be adjusted and ensured, if you remove it you would be unable to do the above settings
the 4017 seems to be not functioning correctly…you may need to check it separately.
break the link between pin6 of 741 IC and pin14 of 4017 but do not remove R4 and the parallel capacitor from pin14.
Now manually touch pin14 to positive with a piece of wire, the relay should respond with an alternate ON/OFF sequence..this would confirm a good 4017 otherwise some other fault could be suspected.
Kristian Tot says
Could you post the pcb layout in the real size?
Swagatam says
provide the shown PCB design to the PCB maker, he'll do the rest.
Kristian Tot says
What is the 1K POT used for?
Swagatam says
for adjusting the sensitivity
Kristian Tot says
Does the mic have polarity? And the relay is 12V ?
Swagatam says
yes MIC has a polarity, check its pins, the one which is isolated from the body ground track is the positive and will go to the IC input pin2, relay voltage must be equal to the supply voltage
Kristian Tot says
What's the exact name of the IC714? I can't find it in any store in mu country by the name 714 or IC714.
Swagatam says
It's IC 741 not 714
Just ask for "IC 741" or "opamp IC 741"
Kristian Tot says
thanks
saikumar sutrave says
will it work for high loads like 60(or)80watts bulb
Swagatam says
yes it will…
Mahesh K Thakur says
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
Swagatam says
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.
pavithra devi says
i dnt knw hw to connect the relay in the circuit can u pls help me
Harish Rao says
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
Swagatam says
hello Harish, what is the DC load that you intend to connect?
Harish Rao says
its 9-12volts sir
Swagatam says
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.
Rishabh masoun says
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……
Steve Carter says
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.
Swagatam says
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??
ifeanyi anthony nwaobasi says
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
Swagatam says
yes you can do it.
AMAN SINGHAL says
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
priy says
what is the output of the relay in the second circuit?
Swagatam says
via N/O
Seok Sothea says
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?
Swagatam says
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?
aspinit says
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?
Swagatam says
which circuit did you make? Try the second one, it will surely work according to me.
aspinit says
Sorry, the first one worked fine it was my fault I was using a polarised capacitor for C2 :S
Swagatam says
OK, thanks!
Seok Sothea says
I try to replace with 1uf to 10uf, but it is still the same.
Seok Sothea says
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?
Swagatam says
any loud sound will activate this device….it's more of a toy than a genuine switching device.
Anonymous says
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?
Swagatam says
You can try the second circuit, it has more chances of succeeding, although both are untested.
Abhi says
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.
Swagatam says
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:
https://homemade-circuits.com/2012/01/how-to-understand-and-use-relay-in.html
Abhi says
Thanks! and I have one more doubt- according to the diagram given at the end of the article on this page- https://homemade-circuits.com/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?
Swagatam says
Yes that's correct.
JACO DE VILLIERS says
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
Swagatam says
Jaco,
you can refer to the following circuits, it closely matches your application:
https://homemade-circuits.com/2012/04/simple-clap-switch-circuit-using-only.html
kkaranjia says
Dear Swagatam i will be sending you a circuit diagram in mail. kindly verify and tell weather it can work properly or not??
Swagatam says
OK, you can send it
kkaranjia says
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???
Swagatam says
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.
https://homemade-circuits.com/2013/07/simple-100-meter-rf-module-remote.html
kkaranjia says
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
Swagatam says
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:
https://homemade-circuits.com/2013/07/simple-100-meter-rf-module-remote.html
kkaranjia says
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???
Swagatam says
Dear kkaranjia,
Yes, it can be used but what will you insert in the RF stages.
kkaranjia says
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
Swagatam says
I responded to your previous comment where you mentioned TX2b and Rx2b chips. These chips require RF stages for operating an RC model
kkaranjia says
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.
Swagatam says
Dear kkaranjia,
I was referring to the following circuits:
datasheet.eeworld.com.cn/pdf/SILAN/153017_RX-2B.pdf
anyway you can send it to my email ID.
suthaharan luxan says
sir i am new one to this…will it work sir ?
did u check it sir ?
kkaranjia says
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.
kkaranjia says
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.
Swagatam says
Dear Kkaranjia,
Refer to the second circuit in the following article:
https://homemade-circuits.com/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.
kkaranjia says
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
Swagatam says
Hi KKaranjia,
I think I already have a couple of such circuits posted in this blog:
https://homemade-circuits.com/2013/03/energy-saving-intelligent-automatic-led.html
https://homemade-circuits.com/2012/09/pir-controlled-led-driver-circuit.html
kkaranjia says
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??
Swagatam says
Hello KKaranjia
Please provide a detailed description of the whole concept, it would help me to design the circuit more easily and correctly.
kkaranjia says
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??/
Swagatam says
though I am not sure who is Satyam here, I have replied to all your previous comments, please check them out.
kkaranjia says
sorry by mistake i typed wrong name.
fathul syafiq says
What is the advantages and disadvantages for this kind of circuit??
Khairul Islam says
Hello Sir, Can I use audio signal ( such as as mobile message or missed call ) place of the microphone?
Swagatam says
Hello khairul,
how do you want to connect the audio output of the cell phone?? through a wire??
Anonymous says
sir, i kudnt get an electrate mic in my locality. Can i use a speaker in place of a mic?
Swagatam says
no, speaker will not work
Sherwin Jan Cabatan says
sir plz… post the PCB layout..
Martin Palmer says
what will this designs power consumption be like once acivated ?
Swagatam says
around 50mA while the relay is ON, and 5mA otherwise.
Johnichan Parampans says
Great
kkaranjia says
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
Swagatam says
C2 positive is towards R5. 63V capacitor will work.
But this circuit has not been tested practically.
Anonymous says
hello
What is the T1 transistor ? Please give me more information about it. Please
Peasy Sousa says
hello sir,
I have a question about the Mic:
-What is the voltage of the MIC?
Swagatam says
It is an electret MIC, not sure about the specs…
Peasy Sousa says
will this one work?
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
Swagatam says
yes, it will work.
Naveen Kumar says
i need data sheet on this project.
Akhilesh P. says
there is a confusion in ur circuit at C2, not define +/- of capacitor, hope +ve of capacitor is connected with T1.
Swagatam says
C2 is non-polar ceramic type….
Akhilesh P. says
it can work on 9V DC also?
Swagatam says
relay will not operate on 9V
Akhilesh P. says
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?
Swagatam says
You can make this circuit and connect the collector of BC557 with pin#14.
https://homemade-circuits.com/2012/04/simple-clap-operated-stairway-light.html
Yes the above circuit has a clapOn/clap OFF feature.
Akhilesh P. says
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?
Swagatam says
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.
Swagatam says
….use TIP122 in place of T3 if you are connecting the motor as suggested above..
Swagatam says
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.
Akhilesh P. says
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 www.minibread.org/wp-content/uploads/2012/04/basic-clap-switch.jpg.
what modification I do, plz send circuit diagram.
Swagatam says
I accidentally deleted your reply, please post it again.
Ezzat Elmo says
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 .
Swagatam says
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.
Namit Singh says
surely will it work ????
Swagatam says
not sure, did not check it practically.
ghanashyam says
how much load can it withstand?
Swagatam says
will depend upon the relay contacts….
Jithin says
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??
Swagatam says
No sorry that won't work…
Shihabudheen PK says
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
Swagatam says
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…
https://homemade-circuits.com/2012/04/simple-clap-operated-stairway-light.html
Shihabudheen PK says
How can i increase the sensitivity of the mic.(I want to move my hands near to the mic and clap in loud noise).
Shihabudheen PK says
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.
Swagatam says
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.
A.Taha says
Hello sir,
Can I incorporate a triac in this circuit instead of the relay? and how?
Thanks.
Swagatam says
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.
A.Taha says
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.
Swagatam says
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.
astitva lal says
do we have to use the same parts for the second one?
Sankar Avp says
pick up the pot from ckt