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Stun Gun Circuit

The post explains a high voltage generator circuit which may be employed as a stun gun circuit for keeping intruders from reaching an individual with dangerous intentions.

What is a Stungun

Please read the following instruction before constructing: Also know as a Taser gun this gadget generates substantial voltage pulses which can disrupt muscle tissues and neurological system, forcing any individual who touches it in a condition of mental bewilderment.

The unit may be used again attacking beasts or dangerous intruders.

Be aware that, this gadget could be prohibited in your country.

It may be extremely dangerous for folks with cardiac issues, who may be using external electronic apparatus (like peacemakers), since it can deliver quite a  little RF.

Don't attempt reckless behavior using this gadget, it is far from a plaything.

The proposed stun gun circuit description may be understood as follows:

The 555 IC is connected as a astable to generate rectangular waves with variable frequency and duty cycle (see the potentiometers and diode).

This signal is fed to a IRF840 Mosfet (not necessary to incorporate totem transistor network, as frequency would be reduced, nonetheless the IC has adequate current potential to swiftly charge/discharge the gate).

As an alternative for the mosfet a bipolar transistor works extremely well (add a 100 ohm resistor between 555 and base of the transistor).

Proper BJT could be BU406, but additionally scaled-down BJT may be ok, take into account that it should be able to cope with a minimum of 2A nonstop.

The inductive boost snubber isn't called for since the electrical power is lower which is practically completely adsorbed to charge the tank capacitor, furthermore because this gadget is battery powered we don't wish to disperse the power on a resistor, yet we need to produce the sparks.

With a snubbing system you are going to encounter decreased firing levels. Utilize A PUSHBUTTON SWITCH FOR Protection

Building the Transformer for the stun gun circuit:

This could be the actual tedious aspect. Because it in retailers we have to construct these. Components essential: enamel copper wire (0.20 mm or 0.125 mm), ferrite rod, LDPE sheets (0.25 mm).

Coat the ferrite rod with a application of ldpe (polyethylene, as a substitute utilize electric insulating tape) and stick it (or tape it) Position 200-250 winding on the ldpe (a lot more winding would do in case the rod is more than 1'), an additional ldpe application, yet another 200-250 winding and so forth to eventually have 5-6 tiers (approx 1000-1400 turns nonetheless supplementary turns wouldn't negatively affect the functionality), then again be cautious for internal arcing that could destroy it.

Insulate it once more and set the primary winding, 15-20 turns of 1mm wire would be simply fine, an excessive amount of winding will probably lead to lesser current and reduced spike in T2 secondary on account of decreased rise period, and too few is not going to saturate the core.

Go for MKP capacitors since they have minimal ESR and ESL (these are popular in tesla coils as mmc capacitors).

The Spark Gap

The spark opening could be straightforwardly a pair of crossed (although not touching) 1 mm spaced wires. It works like a voltage regulated switch, firing when the voltage is just nice to ionize the air between them (transforming it to plasma with smaller resistance).

Remember that it could be sensible do put it into a compact plastic box and stuff with oil allowing bubbles away don't employ motor oil or frying oil, rather organic mineral oil which includes zero water inside.

Circuit Diagram

Simple Stun Gun Circuit

Need Help? Please leave a comment, I'll get back soon with a reply!


  1. instead of making a new transformer can we use the flyback transformer from some old camera or old colour tv???

  2. I'll surely design the circuit for you, the present work load is not allowing me to complete the readers requests.... have patience, you will get the design soon.

  3. Hi swagatam,
    I m very new to ur website, n i ll say u r superb, u r doing one of the best thing by helping hobbyists. Thank you very much. I want an LED driver cum charger circuit for our project. i know u already have thousands of request pending and at the same time u might be working on different circuits, eventhough i want to ask for it, my circuit details are as below-

    1. It's an LED lamp
    2. Having 3volt (0.5watt) of solar panel for charging the battery.
    3. Have to charge 3.6 volt battery from the solar panel (for this may be some boost ic is required ).
    4. Regarding switching---> have one switch---> when all the connection are there the LED should be in off mode---> after 1st press it should glow in full brightness i mean 100% duty cycle----> 2nd time when i press 2nd time the switch the LEDs brightness should decresed by 40-50%---> when i press the switch 3rd time the LED should get more dimmed(say the brightness should decreased by 70-80%)----> and when i press the switch 4th time the LED should get off.
    5. Circuit should be very compact(made up of very few components) and no use of microcontroller plz as, i dnt have that much idea about the microcontroller.
    6. Also suggest the best LED for brightness whether it ll be an SMD LED and it's specification.

    it won't be so difficult for u sir. i m bookmarking you this page for your reply, as i know from ur site, ur best thing is u used to reply almost evryone. keep doing it. A positive reply is expected from you. Thank you very much.

  4. Thank you Ashutosh,

    Let me free myself from the present work load, Rest assured all the pending requests will be completed at the earliest.

  5. Thanks and do we need flyback with any specific set of parameter and is there any specified connection schematics for flyback transformer

  6. It will be just like an ordinary step-up transformer having primary and secondary winding, you will have to identify them correctly and connect.

  7. You will have to employ a high frequency fluorescent tube driver circuit and operate it an AC/DC adapter.

  8. ok thanks for the info... that wont be a problem

  9. find an old MW transistor radio and check for the small transformer near the speaker end of the PCB.

    It's called radio audio transformer, you can use with the above circuit for TR1.

    see the image here

  10. Sir what type of capacitor are 10n/400v are they electrolytic polyester or ceramic and can i use 400v 2.2 micro fared electrolytic cap. Sir it will be helpful if u give a image link to all capacitors .

  11. 10n/400 are metallized polyester capacitor, it would look like this:

    2.2u electro will not work.

  12. hello sir, can i use 104k/400v cap instead of 10n/400v. will the output same. thank you

  13. Hello Gurpreet

    I am sorry it won't work, you will have to use 0.01uF only, that is 10n

  14. Dear Sir, can i use mosquito killing bat circuit for the stun gun circuit because it is very low cost. But it does not spark because its output is low so is there any process to increase the output using common components. plz help me sir... Thank u ......

  15. Dear Gurpreet,

    To increase its power you will have to modify its ferrite coil winding, you can try opening the secondary winding and rewind it with an additional wire in paralel to the existing one in a bifilar style.

  16. Sir, Can i use 0.010/k 400v/ppc cap, is that 10n. I asked the electronic shop for 10n cap they told that this is .01 mfd and 400v. I am confused, please help me....

  17. Hi Gurpreet, yes, 10n = 0.01uF

  18. Thank you very much sir,
    sorry to disturb u again. Sir as you told that i can get transformer from an old MW transistor radio. I don't have that but i have got ferrite rod from a radio. I think it is 1/2 inch, how long i should cut the rod ? Can i open the previous winding and re-wind the same with 1/2 mm wire or 1 mm is the only one, if can then what will the no of turns. And can i wind secondary from a 12v relay coil wire ? Will the output same... Sir thank you for your excellent response...

  19. Hi Gurpreet, you are welcome.

    1/2 inch is too small, did you mean 1/2 foot or 6 inches?
    Do not try to cut it, it will break and spoil everything, use it as it is.
    Throw away the previous winding and start everything in a fresh manner exactly as given in the above text.

  20. Thank you for the response sir, The thickness is 1/2 inch and length is 6 inch.
    Ok sir i am trying it. Thank you....

  21. Sir , i am making stun gun as my major project in college.I have used the same circuit as given by you.I have used the same components ( rating wise ) as given .But i am not getting the required spark.I have measured the voltage and current and found that circuit is using 12 v and drawing around 450mA .
    so how can i decrease this huge drawing of current and how to get more spark.
    Please help.

  22. Manish, remove the mosfet and use a TIP122 transistor instead and check the response, I think the mosfet may be faulty or not responding to the IC oscillations.

    I hope you have made the inductor as per the given data

  23. Sir, is there any other circuit for stun gun, which may be used.As I want to make a small stun gun (size) having the same power.

  24. Manish, the above explained design is perhaps the most compact you can get, you can replace the mosfet with a TIP122 and eliminate a few capacitors and diodes from the output stage to make the design yet more compact

  25. Also sir , can i use 2 transformers instead of 1 for increasing the output , and what would be the effect of that on the overall circuit size.
    Thanks for your valuable time.

  26. 2 transformers won't be required, you can do it by slightly increasing the thickness of the primary and secondary wires of the existing transformer...

  27. Can you please describe that what type of transformer should I used in this circuit?
    Please tell me all the ratings of the transformer, which is easily available in the market.
    And can we use IRF530 mosfet instead of IRF220. Because IRF220 is not available.
    Should we use ceramic capacitors in this circuit or electrolytic capacitors??
    And also tell me the ratings of capacitors used in the voltage multiplier circuit.
    battery used in the circuit is 9v lead acid battery and diodes are IN4007??
    It would be helpful to us if you answer these questions

  28. Instead of making a transformer, can we use the transformer of Fly Swatter (mosquito killing bat)???

  29. the transformer is hand built over a suitable ferrite core material.

    any N mosfet rated at 30V, 10 amp will do the job nicely.

    use polypropelene (PPC) capacitors for the multiplier stage with 630V rating or above.

    BA159 for the diodes would be better, although 1N4007 can also be tried.

    yes use of a lead acid battery is recommended for this circuit

  30. Dear sir,

    I have have sucessfully made the above circuit but i want more longer arc, should i have to add more capacitor and diode in voltage multiplier if yes then should they be of same rating or higher rating will do the job.

  31. dear gps,

    instead of using more number of caps/diodes you can just increase the number of turns at the secondary of the transformer...if possible use multiple parallel wires for winding it instead of of one single wire....

  32. Dear sir,
    Can you please explain the following

    1) What is the output voltage of the Ac from TR1..
    2) What is the frequency of the output Ac..
    3) What will be the effect if we add 8 stage voltage multiplier..


  33. Dear gps

    the output voltage will depend on the winding data.....could be somewhere around 2kv.

    frequency can be calculated using any 555 online calculator, for an iron core trafo it should be within 1kHz, and for ferrite it must be set to around 50kHz

    the ladder network steps up the trafo voltage 5 to 6 times more depending upon how many steps are used in the ladder

  34. Dear sir,
    I am getting two problem firstly the sparks are irregular that means there is a time interval of 3 to 5 sec in each spark. Secondly irf840 heats up too much within seconds, adding heat shrink is of no use. What should i do...

  35. Dear lovely, try adding a few more turns to the winding which is in series with the mosfet and check the response...

  36. Hello , i build this circuit but i use a small step down transformer (220 to 12 ) and here impendance is 1.2k primary 6.2 ohm's secondary but the stun gun d'ont work

  37. check and confirm frequency at pin3, and voltage at the output of the trafo...

  38. Help!!
    I've been struggling to build this stun gun, but something's been bugging me... After I add one voltage multiplier I get 600V output, but adding another one reduces it to 420V!!
    What is happening??

  39. not sure what may be causing this, may be the capacitors are not of good quality, try replacing them with 600V PPC capacitors and check the response.

  40. Dear sir,
    You helped me a lot thanks for being in touch. Sir actually i had a problem which was discussed in previous comments but the problem is not solving. My main problem is that IRF840 is heating within seconds. After adding heat shrink it is same but output response of the circuit is excellent. Is that normal or not ? As you told to rewind secondary coil with additional wire, i tried but it is same and i also use step up transformer from lcd monitor and others but same result. I cannot understand why this is happening to me, it would be very helpful if you could explain me what is the fault which is heating IRF840.

  41. Thank you Gurpreet,

    I guess it could be due to the 555 frequency not matching the can either try altering the frequency a bit (increase it) or add a few more turns in the primary winding (mosfet side winding)...and check the results. By the way IRF804 is not the recommended mosfet for the stun gun circuit, you could try IRF540 any similar.

  42. sir please give all component values......specially diode and transformer capacitor.....

  43. Ashish, please click the diagram to enlarge you will be able to see all the required parts in the diagram....the mosfet can be replaced with a TIP122 transistor

    use BA159 for the diodes trafo data is given in the article

  44. i didn't get the idea about transformer, can you please tell me rating of transformer and the voltages required at primary and secondary?


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