A Royer oscillator with 2 IRF540 N-Channel mosfets, a 0.47uF Capacitor and a 1500uH inductor used for a simple DIY induction heater. The mosfets remain cool, even with such small heatsinks. An isolation transformer was used for the first test with a work coil of 20turns, then the transformer was removed and a work coil of 7+7 turns connected directly to the oscillator.

Here are the schematics for the two variants:

Construction is easy: small heatsinks for the mosfets and 12V regulator, capacitor close to mosfets and coil, tick wire in the work coil. For any other questions, use the comments form below.

The 2000uH ferrite inductor closeups:
P1130611 P1130612

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108 thoughts on “Simple DIY Induction heater

  • July 25, 2014 at 12:33 am

    Hi mr Mortisan. thanks for your post about IH. is it possible to use other type of working coils, e.g pancake type, with this circuit?

  • July 25, 2014 at 8:54 am

    @Abraham your initial 18V supply was probably too weak. You need a supply that can provide at least 5-6Amps.

    @Zenal yes

  • August 19, 2014 at 12:24 am


    I have built this circuit multiple times with no luck other than the fets heating up. Using the identical components in your schematics. I just would like to confirm with you based off your response to Abraham. The PS must be at least 5 Amps? My end use goal is i need to get a similar setup running off of 4V/1A max.

  • September 23, 2014 at 1:00 pm

    What for is the BYV26E diode? Thank you sir .

  • January 3, 2015 at 8:55 pm

    sir, can you advise me to make high frequency heating coil and also wanted to know is it possible to reach high temp like about 1700 deg celsius using induction coils
    thanks If these temp can be reached what is the current usage ?

  • April 16, 2015 at 4:24 am

    i’ve made thi stuff according your scheme. its work well with work coil that size. i want to make bigger work coil with cooper pipe. the question is how much the inductor needed? and the capacitor? what is the formula? (i used 10 A transformer) please respon, tis is really important. thank you.

  • June 29, 2015 at 7:12 pm

    I have a very similar circuit running very nicely the main difference being the values of the tank circuit components. My circuit runs at 405KHz. I have the requirement of ramping up quickly, then running at a controlled temperature. I have tried inserting PWM control of this setup by draining to ground through a diode just after the current limiting resistors and by interrupting power at the source. Neither worked. The drain method failed to break the oscillation and the circuit just kept heating which surprised me…I really expected that to work. I am guessing that the internal resistance of the drain diodes allowed enough voltage in the circuit to energize the gates on the MOSFETS. Interrupting the power at 200Hz blew up all 3 ICs…thats not good. Has anyone been successful controlling this circuit and how?

  • April 9, 2016 at 2:31 am

    I built your circuit and finally got it working. Kept burning up MOSFET’s, Had to use STP40NF10 rated 50 Amps.
    I am sending the screen shot of oscilloscope, getting a good sine wave but I believe I’m not getting zero volt switching (ZVS). I think that is what is heating the MOSFET’s. What is your opinion of the Scope Trace?

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