Gadget in Extremis: DIY induction heater

When I was a kid, there were books of things for boys to make and, I kid you not, one included a mains-powered Pb-melting induction furnace complete with transformer winding hints and tips.


Sadly, gone are those adventurous days – and probably gladly as I suspect some people who tried it probably got burns for their troubles.

Now DON’T TRY THIS AT HOME*, but Richie Burnett has made something similar and put it up on his Tesla coil website.

Update: You can buy an induction heating kit here

* unless you really know what you are doing.



  1. Hi Jeff.
    Interesting, but a complicated way to replace a blow torch.
    Does an induction heater definitely deliver heat better in that application?
    Also, I am not sure I would trust an induction heater off ebay…..
    Keep safe.

  2. There are hand held induction heaters,used to break rusted parts loose on cars. The coils are not center tapped and they are not water cooled. They come with quick change hard copper coils and and a flexible,litz wire to form a coil around something like a tie rod end. They are intended to to get the item cherry red but not melt it. They are supposed to be an up grade over a torch because they can apply better localized high heat faster. These things go for hundreds of dollars and I would like to build one.They come 120VAC and 12VDC to run on a car battery. I have also seen those 1000 Watt heaters on ebay for around 40 bucks. They are intended to be water cooled; the coil is a copper tube. I wonder if they are adaptable. They really look solid and ready to go

  3. Thanks for all that information John. There are some amazing things going on – only a couple of which I was aware of. – and nice to see a current-fed Royer in use.
    Part of my point was that, for god or evil, there is a change in the published projects aimed at teenagers – I am assuming you are not a teenager – maybe that is a mistake?
    And maybe teenagers have not grown up watching parents fix stuff, and would therefore be less able to see the risks in high currents, voltages, and temperatures.

  4. Hi Steve,

    I beg to strenuously differ. This is a golden era of so-called “dangerous” experimentation. True, the government has made it difficult for budding chemist and nukes (but not impossible!) but there is a whole world of other opportunities.

    Take induction heating. Richie was a pioneer in the area but not the only one interested in the art. Consider my pages: Note there are nearly 60,000 hits on the open source Royer heater. Or Jonathan’s 20kW heater: Or Jim’s large heater:

    Moving over to the nuclear side, probably the best known home project is the Farnsworth Fusor, an electrostatically confined fusion reactor. This is actual hot fusion, though far short of break-even or even doing anything useful other than as a source of neutrons.

    Or X-rays. Again the government has made it difficult to experiment with things nuclear but X-rays are the great exception. Used machines are plentiful on the market. A bit more challenging but a step up in complexity is to build your own machine. As an amateur glass blower, I’ve made several X-ray tubes for people.

    Google around for “X-ray art” and look at some of the absolutely stunning artwork people are making using X-rays for the “light” source.

    Making the high voltage, at least for low current tubes, is now almost trivially easy thanks to high voltage, high power IGBTs and FETs. A common General Motors HEI ignition coil will easily make 100kV at several milliamps if operated in mineral oil. One of my “round tuits” is to publish a circuit to do just that.

    I know another fellow who is building a cyclotron using several hundred supermagnets to generate the necessary magnetic field. It goes on and on.

    I love the old books on home experiments and things like the Amateur Scientist columns but home science is at least as alive now as it was then.


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