Dear GeoFusion.

With respect to your second schematic, have you forgotten to draw in the capacitor? Or does it run without one??

Cheers Grum.

Oh and BTW I tried a couple of diodes across my power transistors, I could not see any difference!!

Quote from: Grumage on October 31, 2013, 04:10:57 PM
Dear GeoFusion.

With respect to your second schematic, have you forgotten to draw in the capacitor? Or does it run without one??

Cheers Grum.

Oh and BTW I tried a couple of diodes across my power transistors, I could not see any difference!!

Grum:

Oh snap!! Thnx for notifying that to me. Let me fix that in a hurry.

Hmmm so the Diodes did not much to help, Might be then to change to resistance? or Wattage of the Resistors.

cheerz~

Quote from: NickZ on October 31, 2013, 11:32:42 AM

   Sorry, it's not enough for you, but it's what I can do at this time. My meters have all fried the amp scale also, just like Geos. I will replace them when I can, so, that I can burn up some more.

   The idea with using a bigger battery is not what I have in mind, as the battery is only for kick starting the device, and not to be used as a "run battery"  for as long as possible.
This is once the self running aspect is obtained. I know that using more batteries, like 24 or 36 volts, would give higher outputs, but the transistor heat issue is not resolved yet, even with a 12v battery.
  I may use another battery soon though, as I'll be buying a new one for my car, and can possibly use the old one for this, or not, depends.
  Last night I blew another (one or both) Fets, testing for the feed back path.
That's life...

Oh man, you are a quite danger for these meters.  I fry myself a few including my 2 ch. scope (this I fry 3 time with radiant stuff ), but managed to repair each time. No plenty of money to replace them with new one. 

I know what battery idea is, but the fact that there is big heating issues , imply a large amount of current drawn from battery, so..
Didn't cool enough your fan cooler?

Ok this one is with the cap that i missed 


Grum and Nick :

there is also the other part schematic showing how to minimize the heat. 2nd pic is the one I currently use that holds the circuit good for a longer period without getting hot that fast. or not at all. maybe a bit warm
By adding (2) 10Kohm 's and (2) Zeners of 12V, 15V or 18V. as seen in 2nd pic.

Cheerz

Quote from: Grumage on October 31, 2013, 01:20:03 PM
Dear Nick.

Bad news with regard to your FET's but one thing I failed to remark upon in the last 3 vid's posted is that my power transistors are only warm. In fact my base resistors get hotter!! And that is because they are under rated.

My own thought is that your overheating is being caused by the internal flywheel diodes. You must have seen the high voltages I am recording?? And in my personal opinion I really do feel that this effect is enhanced by the lack of diodes!! Now as a quick fix try adding a couple of fast high current Diodes externally and see if the overheating is reduced.

Cheers Grum.

Hi Grumage!
The reason your Power BJT stay only warm is you use less thicker magnet wire in you primary with more turns which result in more resistance and inductance, and more than that I see in your vids a generous heat sink, Nick use a only small one.
IMO the Nick's heat issues is not from internal fet diode, the switching capabilities of those are far beyond this setup requirement.

@Nick
If it's not to difficult for you, may use a processor heat sink with fan as Akula did, this must solve your heat issue for sure, but must electric isolate transistors from heat sink, if both on same heat sink.