I am looking at a building an electronics project that calls for a transformer with a specific turns ratio '1:4:50', and am trying to source a component. I am working on the project from this tutorial: https://circuitdigest.com/electronic-circuits/diy-stun-gun-circuit

When I search power transformers on Mouser or Digi-Key there is no option in the parametric search for turns ratio. The only category that does have a turns ratio option is 'Current Sense Transformers', but after reading up on these devices (used for metering AC current draw) they seem incorrect for my application. The purpose of this project is to use the transformer in "flyback mode", building up a large DC charge from a small AC signal at the input. I am assuming for this application I need a power transformer.

This part has been weirdly impossible to source, which seems strange as the application isn't that esoteric. Can anyone give advice on how I would go about searching for correct component?

  • \$\begingroup\$ You need to build it yourself so contact the designer and ask them what ferrite core is used and what diameter wires and what insulation ratings on the secondary. If you don't get this near-enough right it won't work. Happy hunting. Also why are you so fixated on killing bugs (previous questions etc..)? \$\endgroup\$
    – Andy aka
    Aug 10, 2020 at 18:55
  • \$\begingroup\$ I think transformers are often custom-made (because everyone wants different turns ratios). Luckily, it's not too difficult to make one by hand. \$\endgroup\$ Aug 10, 2020 at 18:56
  • 2
    \$\begingroup\$ that device may be illegal in your country \$\endgroup\$
    – jsotola
    Aug 10, 2020 at 18:57
  • \$\begingroup\$ @Ocanath Not enough experience, huh? hammerheadaudio.com/designs \$\endgroup\$ Aug 10, 2020 at 19:04
  • \$\begingroup\$ @Ocanath High voltage is a new thing I'm messing around with as a hobby project, but I have a lot of experience electrical engineering. I linked this tutorial because its one of the few places I've found the transformer specs actually documented. \$\endgroup\$ Aug 10, 2020 at 19:06

1 Answer 1


Transformers are difficult to source in general. My recommendation based on past experience designing low volume one-off flyback transformers is to build your design around the transformer, not vice-versa. Coilcraft is an example of a company that sources stock transformers suitable for flyback applications.

I'm providing this as general advice for people designing transformer-based circuits. DO NOT use this design, or one like it, on a human being. High voltage converters are not toys and should be taken seriously.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.