High voltage generator circuit

First of all let me remind you that this circuit is a very dangerous one. The output voltage of this circuit is in Kilo volts and it can seriously injure you or kill you. Try this circuit only if you have enough experience dealing with high voltages. I have no responsibility on any hazards caused by the circuit. Be very careful. This is a humble request.

The circuit given here has three sections namely oscillator, switching stage and a step up stage. The oscillator is build around a NE555 timer operating at 25 KHz. The output of the NE555 coupled to the base of the power transistor TIP3055 which is the switching device. The power transistor drives primary of the step up transformer at 25 KHz and as a result a high voltage will be induced across its secondary.
Circuit diagram.

high voltage generator circuit


  • A 12V lead acid battery can be used for powering the circuit.
  • TIP3055 must be mounted on a heat sink.
  • T1 can be an EHT (extra high tension) transformer used in television sets.
  • For an EHT from 20inch TV, the output voltage will be 8 to 10 KV @12V supply voltage.
  • This circuit is not an efficient one and is not suitable for any serious applications.
  • Once again, be very careful with this circuit!.
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30 Responses to “High voltage generator circuit”

  • vshal bndodkar says:

    What will happen if I use normal stepup transformer
    12volts to 240volts

  • rafomoyo says:

    thanks for enligtening us in electronics

  • JACK says:

    the output voltage will be 8-10kv and the current will be?

  • ajith says:

    hi sir…can I use this circuit to light flash of camera????pls help me

    • jud says:

      hi ajith. 10kv output is too high for a lamp. it will burn out. if you intend to make a flash lamp, plant a capacitor across the terminals of the output but use a more preferable supply. there are different specifications of lamps so make sure to check your power supply that it must be directly proportional to the cap and the bulb. although use a capacitor which will discharge as fast as the usual cams out there. i am by the way a high school student and just wanna say thanks to circuitstoday.com!!!! dont know much bout electro but wanna learn from you guys!! seetheraman ur my idol bro!!!

  • katz says:

    hi sir, how many turn the primary and the secondary coil make’s high voltage. thanks….

  • martha richardson says:

    i have built many timer circuits like this but the only problem i’ve ran accross is the supply voltage/current,3 to 18 volts,if current exceeds 1.5 amps it will smoke the 555 timer,it has happened to me several times and i haven’t solved this problem. this circuit works well with a ignition coil, jacobs latters,stunguns,and others as well.


    Please Be Careful When Working With High Voltage——PLEASE!!!!

  • Johnsheen says:

    This is a very good circuit. Can we use any LOT drive power transistor instead of the said one ? Could I know the total current consumption at 12V ?
    Thanks a lot for the efforts of the people working behind this.

  • Johnsheen says:

    This is a very good circuit. Can we use any LOT drive power transistor instead of the said one ? Could I know the total current consumption at 12V ?
    This website is really good. Thanks a lot for the efforts of the people working behind this.

  • Venkat says:

    Hi sir, Is the produced output is ac or dc?

    • Mayfield says:

      It will be a pulsating DC in a square waveform at 25 KHz.
      Coils do not work with DC and blocks it, as soon the voltage is being constant, the core of the transformer stops transfering electrons – you have to change polarisation, or make the DC pulsating, to get anything at the secondary.

      So a short answer, no – it’s not AC but DC pulsating at 25 KHz.

  • Jalaris says:

    I really like this web!

  • bikash says:

    i wan’t to make this circuit for my expriment can i generate up to 10000volt from this ckt or not please tell me about this

  • attharuddin says:

    hmmm.. thankss…mr.seetharaman..and im on a project of this producing high voltage with low input..but im not knowleged more abt this High V as im on mY second year of EEE..well i hope i wud make a gud suitable ckt fr huse hold by remodeling this..

  • seetharaman says:

    Hi Attharuddin this is a high frequency oscillator for HV application for testing insulation etc. The output will be in the order of just a watt. The loss in this circuit is quite high and not suitable for your application. use the inverter circuits meant for your domestic application appeared earlier in this column, use it.

  • attharuddin says:

    explain me tat wat wud be the output power(watts)..and if i step down it to 230v can i use it as inverter for general house hold purpose and the output power just lasts for seconds or till the battery drains ???

  • seetharaman says:

    Hi Alone it will be around 500 to 600 micro amps.

  • alone says:

    how big is the output current of this high voltage generator?since the voltage comes in kv
    thanks,and more power

  • seetharaman says:

    Hi Kiran with EHT transformers only you can get 8 to 10kV with a compact size. ordinary transformers will be quite bulky in size for this kV, special type of insulation also required. which will become very expensive.

  • KIRAN says:

    can i use a normal transformer insted of eht transformer
    please reply me as soon as possible.

    from kiran

  • Ahmet says:

    Hi, i have seen a similiar circuit to this one. At there, it was written that, the NE555 output must be amplified to be able to drive the transformer. Transistor here before transformer has a bit like similiar job. but i didn’t understand the term “Drive”. Is it possible to tell me the clear meaning. This will make me feel better. Thank you, regards.

  • seetharaman says:

    Rick is correct. BU208D will be a better choice.

  • RICK says:

    There maybe should be a 1N4005 rectifier placed across the Primary of the Transformer for circuit protection,, Connect the anode to the Collector of the Transistor and the cathode to the +12 volts of the Circuit.The 1n4005 reduces the effect of Back E.M.F. that could destroy the Transistor.Just a positive+++ Suggestion to improve the reliability of this Circuit!!! This is an Awesome circuit here,,,,,,Nice Job and well done here!!!!

  • terry beiss says:

    bobbin used car brand CHITACHI and does not work.

    ‘ve got something best

  • MeeX says:

    any circuits that go up to 75-100kV ? without transformer… PLEASE ..i saw it once, i think it uses 4×1,5V batteries

  • zuber says:

    I ment Power Mosfet

  • zuber says:

    Any Particular reason for using BJT, or is it better to use MOSFET.