Re: ZVS Induction Heater (With pictures and video)
Andrew L., Fri Nov 02 2007, 10:06PM

Quick and dirty induction heater ... niceee

Re: ZVS Induction Heater (With pictures and video)
atomicthumbs, Mon Nov 05 2007, 09:28PM

So all you need is an HV cap and a flyback?

Hmm....

What kind of cap did you use? I can get the flyback easy enough but have no idea of anything else :P

Re: ZVS Induction Heater (With pictures and video)
Wolfram, Mon Nov 05 2007, 10:24PM

Flyback? There's no flyback involved here.

Re: ZVS Induction Heater (With pictures and video)
CompWiz, Mon Nov 05 2007, 10:54PM

I just used the ZVS Driver and instead of winding a coil around the fly back core
I just made the coil like in the picture.

The ZVS driver schematic is here:










Use a big heatsink and fan or your mosfets will end up link this one!

Re: ZVS Induction Heater (With pictures and video)
Ken M., Mon Nov 05 2007, 11:42PM

I use big ones like that! They don't look like that unless the feedback circuit has a "Hiccup" then both fets fire at same time and dump 160V at upto 20A across them, then the silicone on the inside gets spot welded ino a nice blob of metal inside a plastic case.

Re: ZVS Induction Heater (With pictures and video)
CompWiz, Mon Nov 05 2007, 11:47PM

The other fet still works.

that thing emitted a rather large cloud of smoke right at my face when it went
"POP sssssssssss"

I was also using a smaller heat sink

Re: ZVS Induction Heater (With pictures and video)
Danielle, Tue Nov 06 2007, 01:56AM

I built it the only problem I had was the cap failed I only used small TO-220 MOSFETs 150V 80A they didnt get hot with small heatsinks. it worked well though.

Re: ZVS Induction Heater (With pictures and video)
CompWiz, Tue Nov 06 2007, 04:58AM

I just noticed that i used bigger wire for one side of the coil!
maybe thats why it gets so hot..

It stays cold when running flybacks even at 24v(although the flyback got almost hot enough to burn me)

Re: ZVS Induction Heater (With pictures and video)
Tonic, Tue Nov 06 2007, 08:02PM


Probably it's caused by a lower R(ds)on. IRFP250 has 85mOhm. And your?

Re: ZVS Induction Heater (With pictures and video)
Kizmo, Wed Nov 07 2007, 09:05PM



I made one too, performance is poor because my capacitors cant handle such high current. They get REALLY hot in few minutes.

Re: ZVS Induction Heater (With pictures and video)
CompWiz, Wed Nov 07 2007, 09:07PM

Mine barely gets warm.

Re: ZVS Induction Heater (With pictures and video)
Kizmo, Wed Nov 07 2007, 09:27PM

And now those failed completely.

Maybe i make small mmc for better dv/dt

Re: ZVS Induction Heater (With pictures and video)
CompWiz, Thu Nov 08 2007, 06:41PM

I made a new work coil with all the same size wire,

the mosfets stay cool now but the coil glows red hot after a minute...

Re: ZVS Induction Heater (With pictures and video)
Kizmo, Thu Nov 08 2007, 11:38PM

My ZVS is back, with small mmc array (total 1.6uF/550V) :)
http://koti.mbnet.fi/kizmo/HV/zvs_flyback/ZVS_mmc.jpg

Capacitors stay stone cold even if i push this thing over 1kW. Performance increased A LOT!