Hi. I'm a mechanic and sometimes I just need to warm one bolt before I can remove it. Induction heater for mechanic is costing to much for me. So I looked inside a cheap Ikea induction heater and I saw that the voltage is high. Do you think is there any way to make a "safe" induction heater from one of this?

 

Generally there is very low voltage on the output of a HF induction heater, it is high frequency at a fairly high current.
Do you have a link to the Ikea?

 

I gather something like this. My read is they can get expensive. Yes, you can roll your own but it is not easy. Most enthusiast start with something like this. I am also seeing various coil kits like this one. The problem becomes matching the inductive heating coil to the circuit. I have no idea how well the coils I linked to will work with the unit I posted. You can figure this much. Good induction heaters draw high current. A 1.0 KW u8nit at 48 volts will draw in excess of 20 Amps. Yes, you can actually roll your own building a circuit using discreet components, a Google of Induction Heater Circuits should get you some results. Parts placement is important as you want the thing to oscillate the instant power is applied.


Ron

 

I ended up basing mine on this one.
Lots of articles on it out there.
https://markobakula.wordpress.com/power-electronics/500w-royer-induction-heater/

 

I ended up basing mine on this one.
Lots of articles on it out there.
https://markobakula.wordpress.com/power-electronics/500w-royer-induction-heater/

I played around with one of these. My goal was to anneal brass cartridge cases at the case necks. It did work but once I got dwell times and other mechanics worked out I went back to using the old tried and true blow torch method. ? My power supply is an old linear supply which weighs as much as I do, well almost.

Ron

 

My power supply is an old linear supply which weighs as much as I do, well almost.
Ron

Mine was too !!

 

https://markobakula.wordpress.com/power-electronics/500w-royer-induction-heater/

So, you can confirm that this is a valid working solutions? I don't have any problem about the power supply.

 

As can be seen in the YouTube video, I used the same WIMA caps also.

 

sorry i didn't understand that was your youtube channel.
In order to prevent fail may I use cap with higher voltage instead of 160 may I use 400v? Since the Cap in paralel are going to do a bigger cap (16*0.27=4.32uF) why you didn't use one cap with 4.32uF?

 

Not mine, just an example.
The main reason for several caps is cooling.
The coil itself is water cooled, of course.

 

e.g. Very High Powered HF systems use water cooled caps.

 

After you tell me the reason of using many cap i went to look if there is any liquid cooled cap and I saw this kind of cap. What do you think about Chinese cap https://it.aliexpress.com/item/3240...!sea!IT!2325086136&curPageLogUid=GH9Khm35RIXu
or is better if I choose quality cap? Many time ago I read that even the coil geometry is important to make it working well. But I saw even professional induction heater use simple cooper rod to give whatever you need geometry.

 

Use the genuine WIMA MKP4 , I do not trust Chinese origin for this application.

 

The induction heater module I played around with was a 1.0 Max KW unit. The caps are .33 uF and there are six in parallel. I do agree with Max on this. No cheapie components. With the actual work coil? I wound a few using 1/4" (6.35 mm) copper tubing. Figure the work coil in parallel with the capacitor bank in part determine the frequency. If the instant power is applied oscillations do not start you will have one or the other MOSFET go into full conduction and the circuit will remain in that state. It will burn itself up. Anyway use quality parts from a quality supplier.

Ron

 

Back in the '60's I looked after some HF equipment in the automotive manuf. industry, the oscillator used a transmitter valve (tube) , I remember that just the filament heater for the cathode, was rated 3Kw.

 

I start bought this Philips Cap https://www.ebay.it/itm/334370936074

 

Good start, you want about 6 to 8 of them.

Ron

 

An easier way to heat things is to just put a high AC current through them. Cut the high voltage windings out of a microwave oven transformer and wrap it with some thick (#6?) wire, then make a couple of thick copper or brass electrodes to put that current through the thing you want to heat. My friend made one; it works a treat for loosening rusty nuts.
Building an induction heater will be a project in itself. If you need it for work, just get one of these and be done with it:
https://www.aliexpress.com/item/1005004702516488.html
Same friend got a broken one like that for free; I diagnosed one or two dead IGBTs, bought equivalents on Aliexpress, he soldered them in and it works. (I was afraid there would be other dead components, but apparently not.)

 

An easier way to heat things is to just put a high AC current through them

I was going to suggest that but figured I'd get pommeled for it. Years ago before getting an acetylene torch, I would use my AC arc welder. Clamp the ground cable to the part and using a copper rod in the eletrode holder put on the bolt, it would heat up the bolt and allow the rust to loosen. It does work better with two people though one holding the copper rod on the bolt and another turning the welder on and off, no sparks that way.

 

Yes it's one of the solutions for rusted bolts but induction heater have wide application. btw my friend tell me when he wanted to remove bolt from the tracks of his bulldozer he just tight them hard and they broke. If you try to remove normally they are hard to remove.