Kapanadze Cousin - DALLY FREE ENERGY

[itsu]

Any doubts remaining?

Hmmm,  right, so even if there was a short in the isolation between start and end of W1 (shorting out this coil), then the low duty cycle of the MOSFET could not cause any high current to occure which would account for these flames.

Strange indeed, it seems there are strong electro-mechanical forces acting on and in this toroid when peaked.

Regards Itsu

[verpies]

@All
Please help me out to understand what broke Itsu's core and what is heating it up - preferably with some decent quantitative reasoning.

Please read my previous posts and don't write that it is due to resistive heating of the winding.

[TinselKoala]

FWIW.... I had a ferrite core shatter inside one of the 100 uH chokes I use in my wireless transmitter system. I think the failure went like this: the choke wasn't rated for the current in the first place, and the windings shorted across the layers from overheating, then when that happened it failed the mosfets shorted, the full unfused battery current rushed in, blew the mosfets apart, opening the circuit. When I dissected the choke I could see that the ferrite was shattered right underneath the area where the insulation broke down. Nonconductive ferrite material.

However I think in Itsu's case it's a magnetic phenomenon. The core heating is from the "induction heater" effect, even though the material is supposed to be nonconductive, and it's possible that such a severe surge happened that magnetostrictive action cracked the ferrite material. Just guessing....

[itsu]

Since it is impossible to synchronize two free running oscillators without some kind of phase locked loop, then even when U1 and U2 are tuned to the same frequency, their phase difference will slowly drift... allegedly hitting the "sweet spot" once in a while .......

Right, but even then no sweet spot has been found..... yet.

I put all my parts together according to this:

# Powering the TL494 (only using the part for driving L1 with 4.1Khz) with 14V PS1
# L2 tuned to 4.1Khz resonance
# L3 pulsed with the nano-pulser driven by 16V PS2 (logic/MOSFET driver) and seperate 200V DC PS3 for the drain voltage
# L4 loaded with 12V/21W bulb (measured by the red probe), so not rectified.

No loopback, just powering the Dally coil and see the output signal under load

Video: http://www.youtube.com/watch?v=XhbmNGoLOw8&feature=youtu.be

Regards Itsu

[verpies]

However I think in Itsu's case it's a magnetic phenomenon.

I think so too. I ruled out resistive Joule heating. I did not rule out the influence of the electric field on the non-conductive core as described by Konrad and Brudny in the 2005.10 IEEE article.

The core heating is from the "induction heater" effect, even though the material is supposed to be nonconductive,

Nonconductive ferri/ferromagnetics can still experience heating due to hysteresis loss.

and it's possible that such a severe surge happened that magnetostrictive action cracked the ferrite material. Just guessing....

That's possible too, either the winding has contracted and squeezed the core mechanically or the core contracted itself nonuniformly causing localized acoustic/mechanical stress, because the winding is not uniformly distributed along the core's circumference.