DIY Induction Heater Builds and References

[Piteer]

I used an esp32 that I programmed so I could set the target temperature over bluetooth. Then I connected a 36v 15a mosfet to that so I could power on and off the induction heater according to the current temperature. Worked very well until I blew a power supply because I made my coil of less wraps to increase the power.

I'd like to make something like this but reliable, it's proving to be quite difficult to make a reliable ZVS circuit. Some other guy on another forum says it will never work reliably unless we move to very advanced circuits, I'm not entirely convinced it can't be done but I'll probably be paying an engineer to make it more robust so I can use it in a product I'm working on.

I made 3 Induction heater Prototype with IR Temp control, the first is tested for 6 months and still running, now i testing No 3 and so far it work. I used Arduino and a Optocoupler for turn on the Gate 12V supply for the Chinese heater. The HalfPint got too hot so i changed to the original IH. Still have some Program fail but it work !


https://ibb.co/Jwn9pCC7

20250121_224202 hosted at ImgBB

Image 20250121_224202 hosted in ImgBB

ibb.co

 

[Gomaruana]

I made 3 Induction heater Prototype with IR Temp control, the first is tested for 6 months and still running, now i testing No 3 and so far it work. I used Arduino and a Optocoupler for turn on the Gate 12V supply for the Chinese heater. The HalfPint got too hot so i changed to the original IH. Still have some Program fail but it work !


https://ibb.co/Jwn9pCC7

20250121_224202 hosted at ImgBB

Image 20250121_224202 hosted in ImgBB

ibb.co

Very cool! Reminds me of my build, I should look if I still have some images from it. I'm was using it to heat up a full sized ballvape, so that's why it broke down in the end. I did use one for about half a year or something but that prototype had a bit less metal mass to heat.

 

[waungus]

Having a bit of trouble.. I'm following the guide on page 13, but I think I have a different version of the board. It still has a third contact pad and I can't see a ground trace between the mosfets. Is there another guide for this version of the board? I'd appreciate any guidance. here's an imgur link with a picture of my board

https://imgur.com/a/8suJONL

 

[waungus]

Having a bit of trouble.. I'm following the guide on page 13, but I think I have a different version of the board. It still has a third contact pad and I can't see a ground trace between the mosfets. Is there another guide for this version of the board? I'd appreciate any guidance. here's an imgur link with a picture of my board

https://imgur.com/a/8suJONL

I went ahead with some steps and think I might understand it a bit more now... is this diagram I drew up correct?

What purpose does the magnetic wire loop on the other side serve? I'm confused because to me it seems like that's there if you don't want to add a switch, but if you're not adding a switch whats the point of cutting the trace? Is it there if you cut the board and the trace on the bottom is unaccessible?

Also with this board, where would I connect the negative?

https://imgur.com/a/4a5Ur6p

 

[Mr_Hodag]

Is their a build/how-to guide for a temperature controlled induction heater?

 

[waungus]

I went ahead with some steps and think I might understand it a bit more now... is this diagram I drew up correct?

What purpose does the magnetic wire loop on the other side serve? I'm confused because to me it seems like that's there if you don't want to add a switch, but if you're not adding a switch whats the point of cutting the trace? Is it there if you cut the board and the trace on the bottom is unaccessible?

Also with this board, where would I connect the negative?

https://imgur.com/a/4a5Ur6p

ended up re-reading the guide and scouring the rest of the thread - figured everything out. no need to reply to either of my previous posts if anyone planned on doing so

 

[Dns18_05]

I combed through the DIY induction heater threads on here the last few days and there's so much interesting information. I already built 2 IHs for my Dynavaps but I recently got a Tempest and I wanted to modify my first one for use with the Tempest and eventually build a more compact one based on the HalfPint design.
@TommyDee I saw that you were also active in the Tempest thread, are you using the IHs you built with your Tempest or only with Dynavaps so far?

 

[TommyDee]

Hey @Dns18_05 I haven't fired up the Tempest yet. I'll probably be using the Wand to start. I need to see where it lands on the power draw compared to my caps.

I haven't played with ball vapes but the idea you can heat them more aggressively seems likely. I'm still open to the idea of using much more powerful FETs.

 

[TommyDee]

Nice work @waungus Indeed, that low voltage switch is to enable to enable the gate circuit. Without that, the circuit will not oscillate. The FETs remain open even with power applied. By default, both the power circuit and the control circuit (gate circuit) are enabled simultaneously.

I think I made the loops to make it more stable to solder the coil to.

 

[Dns18_05]

Hey @Dns18_05 I haven't fired up the Tempest yet. I'll probably be using the Wand to start. I need to see where it lands on the power draw compared to my caps.

I haven't played with ball vapes but the idea you can heat them more aggressively seems likely. I'm still open to the idea of using much more powerful FETs.

Ah I thought maybe you had a Tempest 1 already but that makes sense

So my main issue is that the visual indicator of the Tempest should not be heated. I'm not sure if that also means it should not be inserted into a induction heater's coil. From what I read, only the sleeve around the ball chamber contains iron so it can be heated with induction
I just took apart my first induction heater and bent the coil so I only get 6 wraps of the coil around the ball chamber and that already gave me great results.
But I want to try to build a really portable heater based on your HalfPint design and if I only do 6 wraps, I'd have a lot of excess coil wire. As far as I know, you shouldn't change the length of coil wire, because it would increase current draw? Did you ever change it during your experiments?

https://imgur.com/a/qAz11Vd

 

[TommyDee]

I did the over-wraps to add the extra length. But yes, you are right, narrowing the coil narrows the field. It is most intense in the center. The little indicator is back a ways inside the metal, meaning it is somewhat shielded. I think the hint is indeed to keep coils short.

You could consider going 2S and shortening the coil wire to around 22".