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You are here: Home / Security and Alarm / Ultrasonic Weapon (USW) Circuit

Ultrasonic Weapon (USW) Circuit

Last Updated on November 7, 2019 by Swagatam 80 Comments

The post discusses a simple ultrasonic weapon circuit also called USW, using very ordinary parts such as IC 555 and a few other passive components to generate the required ultrasonic ear piercing sound.

Controlling Crime with USW

With rising crime in today's society, especially against woman, carrying some sort of effective weapon has become quite imperative.

However keeping weapons like a hand gun can be too risky and dangerous as it can lead to deaths or severe injuries and might instigate legal interventions.

A great option which can be as effective in such cases yet won't cross dangerous limits can be in the form of a USW or an ultrasonic weapon.

What is a USW

An USW is a device or an electronic circuit designed for generating ear piercing, unpleasant frequencies that may be capable of causing intensely disturbing or painful affects for the assailant. when targeted toward the human attacker or an animal.

This sonic devastator will generally work with amplified frequencies of around 10 to 15kHz with a sweeping effect, resembling the sound created when we scratch our nail on a bar of chalk or limestone (amplify it 50 times).

Such USW devices are already available in the market but making one at home can be real fun and also useful.

A simple version can be witnessed below which incorporates a couple IC 555s for the intended actions. The proposed ultrasonic weapon circuit may be understood as follows:

Basically both the ICs are configured as astable multivibrators, but the one at the left is used as a slow rising and falling ramp generator or triangle wave generator.

Circuit Operation

The IC 555 at the right is wired up as a high frequency generator determined by the 1.5k resistor, P2 and the 0.01uF capacitor.

The slow rising/falling ramp from across the 1uF capacitor of left IC555 is applied to the control input pin#5 of the right hand side astable IC555 stage.

The above integration results in an high frequency sweeping voltage at pin#3 of the right hand IC which is fed to the transistor current amplifier stage consisting of the power transistor  D40D5 or any other similar NPN equivalent.

This amplified current is further fed to a couple of inductors which transform the high current into high voltage frequency suitable for driving high impact piezo transducers or buzzer elements.

For the two parallel inductors, here we incorporate the primaries of an ordinary radio audio output driver transformers and the series inductor can be any type having the value of around 1000uH.

S4 is the push to ON switch used for triggering the circuit into operation.

S1 is for selecting fast or slow sweep effect option, while S3 is the frequency selector switch, to be selected for fixing the optimal frequency range. P2 sets the final frequency to be delivered across the output.

Adjusting the Frequency Sweep

P1 is for correcting the desired sweep speeds.

The whole circuit operates at 18V, lower voltages upto 12V can also be tried with good results.

A battery pack made from chargeable Ni-Cd cells suits good enough for this ultrasonic weapon application.

The whole unit must be installed inside a plastic enclosure made by fabricating plastic pipes in such away that it resembles a pistol kind of appearance with S4 positioned at the trigger button position.

The piezo must be assembled inside a funnel mouth, and whole assembly to be fixed at the tip of the above fabricated gun barrel.

Circuit Diagram of Sonic Devastator

ultra sonic devastator weapon circuit diagram

Transducer Driver Coil Details

transducer driver coil details

How to Make a Long Distance USW

The above design could be effectively used for remote long distance control by configuring it with a pair of RF FM transmitter and receiver circuit as shown below:

long distance sonic devastator circuit

 




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About Swagatam

I am an electronic engineer (dipIETE ), hobbyist, inventor, schematic/PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials.
If you have any circuit related query, you may interact through comments, I'll be most happy to help!

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  1. Search Related Posts for Commenting

  2. Christian Halgryn says

    Sir,
    P L E A S E .. Advise which transmitter and receiver I should purchase for your LONG RANGE USW project, I have all the rest of the components except he TRANSMITTER and RECEIVER Modules.
    Your earnest attention and reply would be highly appreciated thanks
    Christian

    Reply
    • Swagatam says

      Christian, sorry I don’t sell these units from this website, I can only help making the circuits….

      Reply
  3. Jan says

    Hi Swagatam,
    I need your assistance please. I have built your Ultrasonic weapon, however I have problems.
    The left 555 PIN 2 & 6 feeding the base of 2N2222 does not switch the transistor. Without the base connected I get a very slow freq. alternating between 2 & 3V from the IC. When I connect the base the base voltage falls to zero. The transistor is not faulty as I have manually switched it. When I connect the base to IC PIN 3 which output a 1 – 4.5Hz square wave signal then the transistor will switch on & off as per the base signal. On the R/H 555 PIN 3 the frequency is 11-17 kHz & switches on/off as per the timing on L/H IC PIN 3 signal. I do get sound out of the Piezo, but it is really nothing more than a beeper. The volume from the Piezo is rather weak but I can adjust the slow freq. on P1 & the high freq. on P2. I think the weak volume could be due to the speaker transformers & Inductor. I have use equivalents but their values are not correct. I have ordered the correct parts. Should have it soon and hopefully this will correct the volume problem.
    The supply voltage is 15VDC
    I have swapped the 555 numerous times with other IC’s, but symptoms are identical.
    I have tried different values of resistors, but no luck.
    I have checked the CCT and Continuity between components & everything seems to be OK.
    Your assistance will be much appreciated.
    Regards
    Jan

    Reply
    • Swagatam says

      Hi Jan, I had referred this diagram from another site, and it seems the left side astable is incorrectly shown with pin6/2 connected with the base of 2N2222. It should be basically a replication of the right side astable design. So please use pin3 of the IC to drive the 2N2222.

      The piezo will need a special inductor and the piezo will need to be mounted or fixed over a specially design plastic enclosure, for generating a loud noise. Without these arrangements the piezo will be very weak with its output.

      Reply
      • Jan says

        Thank you Swagatam,
        Will you please give me the specs for the special inductor.
        Regards
        Jan

        Reply
        • Swagatam says

          The coil can be any small ferrite rod based coil with 200 to 600 turns on it. Or you can also get ready made “buzzer coils”

          Reply
  4. Trishpota says

    Its working thanks for circuit but when i turning on 10ohm already burned and still working with burning 10ohm what can i do about it?
    And sound a bit weak what can i do?
    Thanks have a good day swagatam

    Reply
    • Swagatam says

      Trishopta, please use a 10 Ohm 3 watt or 5 watt wirewound resistor, 1/4 watt will burn quickly.

      Reply
      • Roel Rebosa says

        Do you have counterpart here in the Philippines where I can buy the kit? Thank you

        Reply
        • Swagatam says

          Sorry I do not have anybody in Philippines who can provide you the kits.

          Reply
  5. Alfredo says

    kindly provide model or supplier because the models I found in the internet has 120 P-P volts.
    if possible the store which sells 40 Khz.

    thanks in advance

    Reply
    • Swagatam says

      Are you asking about the piezo? Please refer to the following article for the details:

      https://www.homemade-circuits.com/understanding-and-using-piezo/

      Reply
  6. Gilberto Lopez says

    Dear Sir

    Good day, many thanks to share this special world of ultrasound, I have one question..can be possible to develop ultrasonic weapon to kill langostas which are affecting African brothers? maybe is to much but must think in a bigger weapon as big is the problem

    Reply
    • Swagatam says

      Thanks Gilberto, I don’t think ultrasound may have the capacity to destroy locusts, at the most it can be used to scare them off but it cannot kill them

      Reply
  7. Mike says

    Hi sir. Making gun from circuit map is a difficult for me, DO YOU KNOW WEBSITE THAT SELL KIND OF USW? Do you have email or whatsapp?
    thank you so much for this site
    Mike

    Reply
    • Swagatam says

      Sorry Mike, we don’t sell any of the circuits in this website, nor do we know regarding any other source

      Reply
  8. stan smith says

    dear sir
    your long range USW, what distance would you think. Also what effect on a human would it have.Would this be the nausea with the sound above hearing ability.
    Thank You

    Reply
    • Swagatam says

      Dear Stan, the circuit will produce a sharp penetrating noise which will cause a painful irritation to the ears.

      the distance will depend on the transmitter/receiver power and range

      Reply
      • stan smith says

        Sir,
        would increasing the number of these increase the range to say 300 ft for a defense also is the output below the human hearing range and if it hits an obstruction would it neutralize the effect.
        Thank You for your time
        Stan

        Reply
        • Swagatam says

          Yes installing the receiver/transmitter in series can increase the range…the frequency will be in the hearing range of humans and will be sharp and loud, obstruction will reduce its efficacy

          Reply
  9. Iokar says

    Hi,
    Thank you for your plans sonic_devastator
    Please send Trans-core size of item1, Diameter and number far wire for use1000 uh.
    Is there a more powerful design for more space?
    Or to increase the area, the same plot is connected to a stronger amplifier.
    I am waiting to your reply.
    All the best
    Jokar

    Reply
    • Swag says

      Hi, I have updated the information at the end of the post, please check it out

      Reply
  10. Iokar says

    Hi,
    Thanks for your plans and efforts
    Do you have another powerful plan or
    Does it have a strong amplifier for increases the effective interval
    Transmission core size and wire diameter 1000 uh
    I am waiting your reply.
    All the best
    Jokar

    Reply
    • Swag says

      sorry, presently I do not have it, will update it whenever I happen to find it.

      Reply
  11. Husmukh says

    Dear Sir
    If I want to use this circuit to drive a, say 4 or 8 Ohm speaker, can I just use the the BD139 to do so and use a 12V supply?
    This is to use it to chase away rats (and the occasional dog) which come in from the fields, so the frequency should also be above the human threshold of say 17kHz.
    I will change the values of the voltage divider to pins 2/6:
    P2 10k Ohm to 2k Ohm, R1.5k to 1k Ohm
    R3.9k Ohm to 2k Ohm and leave the Capacitor at 0.01uF.
    to get the desired frequency range.
    I hope this should work.

    Reply
    • Swag says

      Dear Husmukh, yes you can try that, BD139 will work with a 8 ohm speaker at the mentioned frequency. However I am not too sure whether dogs really get disturbed by ultrasonic sounds or not….in fact they will get disturbed just like us if the sound is sharp and ear piercing type.

      You can experiment with it and check the response.

      Reply
  12. shubham singh says

    what if i want to make the frequency upto 35-40 khz..?

    Reply
    • Swagatam says

      the output will be inaudible.

      Reply
  13. Ipeleng says

    Thanks for the reply and the ideas…much appreciated

    Reply
  14. Ipeleng says

    Hi, out of curiosity, what upgrades would you suggest to increase its effective range? I'm talking here about 300m.

    Reply
    • Swagatam says

      Hi, it may be possible by upgrading the coil and the piezo to handle higher watts and by using a radar kind of transmitter to focus the waves towards the target.

      Reply
  15. Wilson says

    How functional is this? I wouldn't think that something this small would be more than annoying… Very cool though!

    Reply
    • Swagatam says

      thanks, yes may be it won't cause too much trouble for the intruder but it might certainly help to attract a few folks even from some distance away…

      Reply
  16. Ephraim Even-Hen says

    Hii, Will this circuit work with 35Khz oscillator?
    Thanks,

    Reply
  17. Swagatam says

    The sweep configurations look OK to me, can't figure out the issue, try a diode instead of the 1K resistor between the collector of the transistor and S2…cathode to the collector and anode to S2……check the response after doing this.

    Reply
  18. Raman says

    What about replacing the output transistor with a 'N' channel MOSFet. What would be the amplitde across 'CE' of outut?

    Reply
    • Swagatam says

      replacing with a mosfet will not improve anything except the cost which may go higher. Th amplitude would be equal to the supply voltage.

      Reply
  19. Deon Williams says

    Hi again, sorry to bother you.
    I've wired up my circuit but it doesn't function, I suspect the problem to be in the way the potentiometers are wired up..
    Just wondering how did you wire them up?
    Thank you for your help.

    Reply
    • Swagatam says

      Hi, the potentiometers are correctly positioned and varying them will produce the specified outputs.

      What kind of sound are you getting presently?

      keep S2 disconnected initially and check the response, if there's no sound would indicate a certain fault in the connections.

      Reply
    • Deon Williams says

      Sorry I mean with the potentiometer on the diagram, what would it look like physically? I think I may have incorrectly wired it up hence why I am not getting any sound.
      I currently have on the 500k potentiometer the 10k resistor linked to the far right terminal on the potentiometer and then the other 2 connections linked to the far left terminal and then have soldered a wire linking the far left terminal and middle terminal together, is that how it should be connected? I have all the components on a bread board and I have a feeling that this is where I've made fault.

      Thank you again.

      Reply
    • Swagatam says

      left or right pot terminal orientations are not important….short the center lead of the pot with either the left or the right terminal…this joint together becomes one lead of the pot…while the other free lead becomes the other lead of the pot.

      now simply connect one to the positive line and the other to the 10k resistor.

      the joined leads of the pot can go to the positive line or to the 10k that's not critical…because pots don't have polarity.

      Reply
    • Deon Williams says

      Thanks mate! Got it working in the end, I disassembled it and rebuilt it again and managed to get it working.. must have missed something along the way. Thanks!

      Reply
    • Swagatam says

      That's great mate, congrats!!

      Reply
  20. Deon Williams says

    Also, would the MJE182 be a good replacement for the D40D5 transistor? Thanks again.

    Reply
    • Swagatam says

      yes it will also do…

      Reply
  21. Deon Williams says

    HI there,
    I've got all the components except the D40D5 transistor as I can't find it.. Can you please recommend a transistor to use in its place? Thanks!

    Reply
    • Swagatam says

      Hi …the transistor is not critical, you can try any suitable 2 to 5 amp NPN transistor such as BD139, TIP31, D1351, D880 etc

      Reply
  22. Norbel Semaj says

    Hi the pn2907 is only pnp why in the schematics is npn?

    Reply
    • Swagatam says

      yes thanks, it should be actually 2N2222…

      Reply
  23. eshkariel tapiador says

    how will I connect the pins?

    Reply
    • Swagatam says

      use only the outer and inner areas, leave the central small area, see example below:

      https://homemade-circuits.com/2012/04/simplest-piezo-driver-circuit-explained.html

      you will then need stick the piezo on a plastic base

      Reply
  24. eshkariel tapiador says

    Sorry for disturbing you again..
    Can I use 3-point piezo?
    What I mean in audio transformer is the voltage and current..
    Thanks…

    Reply
    • Swagatam says

      yes can be used.

      Reply
  25. eshkariel tapiador says

    And how about the audio transformer rating? thanks

    Reply
    • Swagatam says

      you make one by winding 8 primary and 1000 secondary over any E type ferrite bobbin/core assembly
      wire should be 33 SWG or 0.2mm

      Reply
  26. eshkariel tapiador says

    I opened the piezo buzzer this morning and found no circuit just a 12v piezo transducer…By the way it doesn't sound like "buzzing" but like a "tweeeeeet" ing soung…can I use it? thank a lot!!!

    Reply
    • Swagatam says

      the piezo which am referring to should look like this:

      4.bp.blogspot.com/-MlUEEIZ2MDw/T5zHauzOS1I/AAAAAAAABNE/IsnTWGcUfkE/s1600/piezo+transducer+element.png

      no other types would probably work

      Reply
  27. eshkariel tapiador says

    Can I use a 12v piezo buzzer which looks a lot like encased in black circle thing?!
    how many volts and amps is the audio transformer? cause that's what the salesgirl keep asking me!!! thanks!!! 🙂

    Reply
    • Swagatam says

      buzzer will not work here, you will need to connect only the piezo element without in associated circuit.
      ask for 27mm piezo element

      Reply
  28. achilles hector says

    Hi sir! good Morning…
    can i use any piezo transducer? like what I got in a calculator with beeping sound… thanks!

    Reply
    • Swagatam says

      Hi achilles,

      a 27mm piezo will work the best, you can see the example here:

      https://homemade-circuits.com/2012/04/understanding-and-using-piezo.html

      Reply
  29. achilles hector says

    what are the values of inductors?

    Reply
    • Swagatam says

      i'm not very sure, i guess it could be around 200mH

      Reply
  30. achilles hector says

    can you give me a specific identity for piezo?

    Reply
    • Swagatam says

      yes identically rated separate inductors will also work in place of audio trafos….piezo could be a 27mm 2-contact piezo element, see example in this article

      https://homemade-circuits.com/2011/12/how-to-make-simple-piezo-buzzer-circuit.html

      Reply
  31. achilles hector says

    Can I replace audio transformers with inductors? and if yes, what value?

    Reply
  32. achilles hector says

    thanks a lot sir!! you help me a lot to understand the circuit!

    I have another question.

    1. In your answer in #2, does that mean I'll buy an audio transformer with 8 ohms secondary side, and any resistance on the primary. Or does it need to be 1k ohm?

    2. And I can use BC547!?

    Reply
    • Swagatam says

      you can buy an ordinary audio transformer and use its output winding (speaker side) with the above circuit….the winding which has higher number of turns.

      Reply
    • Swagatam says

      BC547 can be used in place of 2907 but for the output transistor you will have to employ a power transistor such as D313, D1315 or TIP31, TIP122 etc

      Reply
  33. achilles hector says

    good day sir!!!

    may I ask?

    1. Where is the piezo here? What will I tell the counter if I buy the piezo like that in the circuit?

    2. On the far right side of the circuit, is that a transformers in parallel or just a coil? which is 8 ohms, the primary or the secondary? what are the specifications? (in case its a transformer) how many volts is the primary? the secondary? how many amps?how many watts?

    3. Can I replace the transistors with bc547? just in case there is no transistor like that in our place…

    4. The inductor is 1000 micro Henrys right?

    Reply
    • Swagatam says

      Good day achilles,

      1. The circle situated near the inductors and labelled #26 is the piezo transducer, you can ask for a 27mm 2 point piezo from the shopkeeper.

      2. Those are small audio transformers whose secondary sides are only used in the design. You can replace them with any identical high value inductance coil

      3. you can use any similar npn general purpose transistor in place of BC547

      Reply
    • Swagatam says

      ….yes the series inductor with the piezo is rated 1000 microH

      Reply
    • Doug Buice says

      Very new to circuits but I'm getting it, sort of. What specific inductor do I need?

      Reply
    • Swagatam says

      it's a piezo buzzer inductor….or 1000 turns of 36SWG wire wound over a ferrite core

      Reply
    • Doug Buice says

      Thank you

      Reply
    • Doug Buice says

      I am having no trouble finding the 200MH inductors and the 100MH inductors. There are so many. Which one do I choose?

      Reply
    • Swagatam says

      make sure they are capable of handling upto 500mA current

      Reply
  34. OYEKA says

    JC, I WILL LIKE U TO SHARE IDEAS WITH US ABOUT SELF DEFENCE TOOLS THAT WILL BE LEGAL TO CARRY AROUND OR KEEP AT HOME IN THIS UNSAVE WORLD.THANKS. OYEKA : 12oyeka@gmail.com

    Reply
  35. JC Biggs says

    NICE! Was looking for something like this! Does the shape of the outlet tube have an affect on the sound output? I know from my Radar days in the military that the shapes of the tubes are critical. I assume not so much here?

    Reply
    • Swagatam says

      Thanks JC,

      Yes, the radiator shape is indeed crucial here, to be precise the piezo element needs to be mounted inside a conical mouthpiece for effective radiation towards the intruder and for keeping the noise away from the user.

      It's great to have a military personnel with me…honored:)

      Reply


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