Mini Induction Heater

This video shows how I build a ZVS driver to power a small induction heater than can make pieces of metal weighing ~1 gram or less glow red hot. The circuit takes in 10-16V and the final variant shown in this video oscillates at about 160 kHz. I also show how this circuit can be used to drive a flyback transformer.

This is a very modestly powered circuit, but the advantage of a ZVS driver is that it can be scaled up to tens of kW without much of a problem. The voltage on the coil (and the MOSFET V-DS) is about 3 times the input voltage, so to use higher voltages of say, 36 or 48V, I would need MOSFETs rated for a higher V-DS like an IRF250 or IRF460.

NOTE: My statement about inductance not changing is inaccurate. Inserting a ferromagnetic object into the coil *does- increase the inductance and reduce the frequency.

Hardware used:

IRF44 Mosfet
1N4148 Diode
5.6V Zener Diodes
400 Ohm Gate Resistor
10k Gate pulldown resistor
1 uF 630V Polypropylene film capacitor

Music:

Kevin MacLeod - George Street Shuffle
Serge Pavkin - Fractal

[devilssongs]

This video was uploaded 2 years ago, i cannot find any batter videos then this on how to built a zvs circuit. This is a perfect video, even it beats electroboom induction heater video.
This video has everything.

[Raul_Gajadhar]

He has a way of explaining things in his videos, you can't help but understand - hence learn it.

[Shadobannedlife]

Amazing.Electricity is the closest thing we have to magic.

[metalman]

I’m so happy you showed building this in steps and I can tell more about it when you do this

[ArchieHalliwell]

Interestingly, at high frequencies an aluminium wire would only have about 26% higher resistance than copper (with a cable of radius approaching infinity), rather than the regular 58% as the skin depth of aluminium is higher than that of copper. The skin depth of copper at 100kHz is about 0.2 mm, whereas that of aluminium is about 0.25 mm. The radius of the 20 AWG wire is about 0.4 mm and 10 AWG is about 1.3 mm, so the skin effect is quite significant at these frequencies (the skin depth is the depth at which the current density reaches 1/e, approximately the thickness of pipe at DC the cable is equivalent to for large diameters).

[sciencoking]

You might as well always keep your scope probes in 10X mode, that way they have much higher bandwidth

[dtiydr]

Use MKP capacitors not MKS, MKP are meant for pulsed operations and is the ones I used over 10 years ago in mine and worked perfect with no overheating.

[johnrogers]

I don’t remember if I’ve left a comment on YouTube before but this is only the 2 or 3 video of yours I watched and you are so fucking awesome I can actually absorb most of the information you’re putting out and if I can’t get it the first view I can rewatch til I understand which is true for most videos but I feel like you understand things at the very core of their concepts and the way you explain things idk forgive me rambling I have a tough time learning and you kinda made my month and maybe year! Your fucking Really awesome.

[dalenassar]

Try putting the heated metal closer to the heater coils rather than in the center...I have not tried this, but the magnetic field of a solenoid is maximum NEAREST the inside edge of the coil.
I hope someone tries this and comments on the results!!
GREAT

[tzfdhmq]

Nice video! But don't use MKS caps. They have too high dielectric losses and will cook themselves like you showed. You need MKP or even better FKP capacitors that have low dielectric losses.

[jarimesce]

On your comment about adding metal changing the inductance of the coil, I'm a bit torn. It's true the frequency of the signal doesn't change, but we do see a phase shift. I suspect the metal has to be changing the inductance of the output coil, but that's probably not changing the inductance of the resonant circuit (since that's separate, based on the circuit diagram?). The different load inductance just changes the phase of the output, causing it to slide across.

You could check this by comparing a soft iron to stainless steel. The soft iron should change the phase more since it is more ferromagnetic.

[sypernova]

ths is neat. i`ve seen a few videos about this, but none with a buiild that looks as doable as this. since it`s two years old and you mentionned some potential changes, is there an updated version, a new build sheet, that we should try out? thanks!

[mikecamps]

I deal with old school Vacuum Tubes....this appears in schematic as a Long Tail Pair Phase Inverter circuitry to drive a Class AB Push Pull power tube amplifier system and thus the output transformer & possible feedback loop back to the input of the PI. I'll have to look at my scrap parts and see if I have a toroidal coil around to salvage out and brew up a Vacuum Tube Cooker

[scootndute]

Pouring water onto your table with high current and voltage around is wild

[captainobvious]

Was part of melting the wire due to the nut having a hole in the center? Its eddy current would be going around in a circle and making a magnetic flux that would couple back into the coil?

[AnalogDude_]

Did you safe the Falstad circuit?
Could you add the (short) link to the simulation in the description text?
100 milliOhm resistors?

Would like to give this a shot as wel, for heating nuts and bolt on a vehicle.
Could it be run from a vihicle battery?

[victoryfirst]

Can you tell me if the mosfet unit is the most efficient type of induction heater ???? Also, was told that a low frequency that is used in the old General Electric company induction heaters was the most efficient and heated much deeper into the metal, is that true ???
Thank you for your time Sir.

[rodriguezfranco]

can I add some D-S snubbers capacitors to help damp the voltage spikes?? like 1nf or 10nf

[curiousviewer]

Nice and I have a question as you mentioned going up to 12KV.

Would it be possible to 'charge up' the inside of a sealed plastic tube formed into a torus with a negative ion charge by sticking a wire into it, sealing the entry point and running 12KV through the wire (like the negative ion emitter of an ion wind generator)?

If you can, would wrapping it in wire to make a toroid electromagnet out of the tube accelerate the negatively charged air inside (and maybe things that can be charged with static/negative charge that you also put inside like small metal bearings or plastic beads)?

[mokkascience]

Please do basic videos like resonance in lc tank