I already joined the club, years ago, and the pile of dead component are my proof.
  Oh! What fun...  yet no self runner to show for it.  YET.

With  mosfets overheating and popping, my feeling is that your inductors and capacitors are not "balanced". Certainly you can reach your desired oscillation frequency by many different combinations of inductance and capacitance, right? I believe that your inductors are too heavy and your capacitors too light, if you know what I mean. Lowering the inductance and raising the capacitance to keep the same frequency, should reduce the component heating problems I think. It will also boost your power throughput to whatever comes downstream of the inductor windings, I think.

But I probably can't justify those "thoughts" based on theory... just a lot of practice. Here's about six months worth of practice:

 


(Something else that makes mosfets heat up more than necessary is being continuously avalanched. But this might be necessary to "tap the Quantum zeropoint" or whatever.)

  Itsu and All:
  Good to see that you've made some progress from the changes to your yoke coils.  However your secondary coil is still not wound correctly, and should not go all the way around, as you have it. The gap is important, as that is where the three turn output coil will go in the future, and also the output will not be the same winding it that way.  Look at Akula's yoke, or also check my yoke image, once again as well.

  The scope signal looks great, very nice... but, I hear no ringing coming from the yoke, which means that it's not running at anywhere close optimum output yet, but still at the low output low light mode.
    Now, I really recommend buying some NEW 100 watt bulbs, (not using used ones).  I would buy at least 3 to 5, 100 watt, 110v bulbs, as they are very cheap, and work best for this circuit. I've tried many different bulbs. Three to four bulbs gave me the best light output, at least in my case. The most I tried with success is 7 of those bulbs, so far.
  Geo mentioned that he obtained 1000w to 2000w output from his set up. I wish that he would have showed that though. Hi, Geo, I know that your there...

  Once you have several of these 100 watt bulbs running together you will need to see which tuning caps will give the best lumin levels. But, it best to first get the maximum light output possible, BEFORE you try to further tune using the tuning capacitors. This is very important, otherwise you'll be tuning to the low output mode.
  The point of all this, is being able to obtain maximum magnetic output from the yoke coils. So, don't tune with the caps, using just one or two 100 watt bulbs. First see how many bulbs it will take to obtain the best lumin level possible, then use the tuning caps to further improve on that resonance, and brightness level.
   I would also recommend using the same tuning caps that Geo used, which are the 0.33uf, or so, 650v poly caps.. Anywhere from 0.22 to 0.47uf. would work for the yoke input side, as well as for the yoke output side. Remember, it is also a balancing act. I just try on whatever caps I have on hand, to see what combination works best. But, buying the right value caps is much better. Using the proper tuning caps in balance, on both the yoke's input coil side, as well as on the yoke output side is most important.

  Well, I won't bore you with more details, for now. Happy tuning.
     
   NickZ

nick, you get mail yet?
 

   Tek:
   NO, but I talked to the mail man yesterday, and mentioned to him that I'm waiting for that delivery, so he knows.
                                               NZ

I'll send dos mas tomorrow.

On tuning: I think it's easier to tune the load to the oscillator, rather than tuning the oscillator to the load. Tuning the load is done in the same way as tuning the oscillator, by varying inductance and capacitance. Putting a variable inductor in series with the fixed inductance can make tuning the load "sweet and easy". You can look at my electrosmog harvester for an example of tuning the load to the oscillator.
If you must tune your oscillator, try putting a big HV air-variable tuning capacitor in parallel with the fixed-value caps. Once again, keep current paths short, heavy and symmetrical. All the fixed caps in the tank should be the same high-quality low ESR type (poly film or maybe mica) and C and V rating. Little 1 kV 50 pF ceramic caps can be added for fine tuning and then the HV air variable for ultrafine tuning.

The ZVS type driver circuit automatically runs at the resonant frequency of the tank circuit made up of the inductance of the core and the capacitance of the tank caps, and it makes a nice sine wave output if it's working right. Changing to some kind of variable frequency/variable duty cycle drive would seem to defeat this feature of the ZVS oscillator driver.

Hi Itsu,
In Holland  you can still order normal, standard ( old fashioned ) lamps.
The have them from 15 watt up to 300 watt  in  normal E27 fitting.
http://www.gloeilampenhuis.nl/standaardlamp-helder

They have more than enough , they are still produced .. they  told me on the Phone.

   
   Please Geo... do it for the world to see, it's time...  be brave...
I'll back you up, so there's more than just one of us going for it.  Open source...
 
                                                                    NickZ

Yes, please surface again Geo and join Hope Girl to save the world with your GEG - hehe