DIY Induction Heater Circuit With Flat Spiral Coil(pancake Coil)

Induction heating is the process of heating an electrically conducting object (usually a metal) by electromagnetic induction, through heat generated in the object by eddy currents. In this video, I am going to show you how to make a powerful induction heater at home.

For building this project you need:

-Mosfet transistor IRF740 or similar ___4pcs.

-HF choke for 20A or more ___ 2pcs.

-Fast recovery diode 100V/3A ___2pcs.

-Resistor 560 Ohm/5W ___2pcs.

-Resistor 10K /0.25W ___2pcs.

-MKP capacitors with total capacity of 4.5 microF for630V or more

-Work coil made from silicon isolated wire with a cross-section of 2.5mm square

-12V PC power supply from old computer

Тhe base of the device is the electronic circuit called a ZVS driver (Zero Voltage Switching).To operate, a ZVS driver is necessary to have an oscillator circuit consisting of a capacitor and a coil. In this case, it is characteristic that the coil has a flat disk shape that is also used in commercial induction cookers. Also, the coil is made of silicon insulated copper wire with a cross-section of 2.5mm square, instead of copper pipe as is common in DIY projects. This wire is used for servicing electric cookers so it can be found in every tool shop or hardware store.

The advantage in this way is that this wire is much cheaper and the production of the coil is much easier. In addition, silicone insulation is resistant to high temperatures and a very bad heat conductor so that the metal container is placed directly on the wire, and after removing the heated vessel, the insulation of the wire is cold.

As you can see on the video, after removing the heated container, you can immediately touch the "hotplate". Another advantage of this scheme is that it works on 12 volts so can use the standard PC power supply. Mosfet transistors are removed from the old UPS device and are labeled P65NF06, but can be used others with similar characteristics, for example, IRF640, IRF 740, IRFZ44, etc. Capacitors must be quality MKP x2 type for 630 volts or more. The total capacity is obtained from several parallel-connected small capacitors and should be about 4.5 microfarads.

The video also provides a circuit schematic and block diagram of the device. Consumption without a bowl is 45W and at load 220W to 260W.