Itsu:
  Great to hear from you. It's good to know that I'm not the only one in the world replicating Geo's crt.   It would also be nice to hear from Geo, one of these days...

   I've had an overheating problem with my system, so I'm using a 10v, 1.5  amp wall adapter to tune my system, until I find the right combination of caps, chokes, wire turn count etz... that is optimum. Although each time I change something, the whole crt responds differently as well, and the same caps won't work as they were previously.

  I use egg shaped magnetite magnets on the yoke core to vary the frequency, or reduce the ringing noise to bearable levels, or even to no audible ringing level, (at least to me).

  The IRFP260N mosfets are doing a good job of producing useable lumin levels, but at the cost of higher amp draw, which is partly the cause of the heating of the Fets.
I'm not using any zeners at the moment, as I can't find the right ones. But, when using only a 12v battery (or less voltage), they may not be absolutely needed.
  I use three different chokes on my device, as that is what is giving me the best light output, and voltage readings. I don't know what the amp draw is, as my analog meter is not working on the amp scale. Nor can the voltage output at the bulbs be read as well, as meter is giving false readings.

  I'll be connecting the Akula yoke core set up, soon, to see what the differences are, also. And later going to build the RMG, using a flyback core, and air coils, with ferrite pieces inside the pvc pipe. 

  As my main interest is in making a feed back path, not just an inverter crt, I'm still needing some advice as to how to go about it. I don't want to blow more fets in the process, as I only have 6 of them.
  Anyway Itsu, good luck to you and anyone else that is participating on the RMG circuits replications.
  I'll be posting some pics, maybe today, as well as a video, when I have more to show.
 
  Back to tuning for resonance...
                                                NickZ

Any suggestions on how to protect the gates?

A 0.1uF ceramic cap across the zeners (= 0.9 Ohm reactance)?
Replace the 470 Ohm resistors with inductionfree/poor ones?
something else?

Thanks,  regards Itsu

Itsu,

What power rating are your zeners? I use 15V, 5W but faster 15V TVS diodes would be an even better choice. The gates get clobbered on a Mazilli. You could also try a couple of ferrite beads on the gate leads placed close to the mosfet but a power zener clamp should do the job.

Dear All.

Further observations.
I have carried out further tests based upon the video I posted yesterday. With the demise of my VERY expensive HT flyback !!    I resorted to another HT source, un rectified this time. No result !!
It would appear that the effect is only present with a DC HV output. Does this lend credence to Tesla's radiant energy ?? Could our wire be acting as an antenna ??

More tests are required, any takers ??

Cheers Grum.

Hi Grum,

i cannot match the shown diagram with the video.
To me its looks like 2 different circuits, like where does this capacitive wire comes from/goes to?

Anyway, my guess is that you have an inductive coupling into your bulb.
The flyback is already DC (it has internal diodes), so running it through an external diode again will not add much.

And, those crocodile leads are not meant for HV, so please be carefull when using them in this situation!
Use pliers or something else to handle them

Just my 2 cents 

Regards Itsu

  Yes Itsu, I'm noticing similar results as what you mention.
   I don't see how this circuit would have a chance at 24 to 36 volts. But, I'll have to see what it does on the flyback/air coils RMG crt. As that might make a difference.

   I do also notice the "special" dual mode, which can produce more bulb brightness at the expense of higher amp draw/higher heating of chokes, fets, ferrite cores, and components.

  However, there is no shocking from anywhere on this circuit (cold electricity).
And, resonance tuning, to obtain that magic result, is everything here.

  Different bulbs loads also give very different results. So, it may be important to tune using 500 watts or higher loads to see anything "unusual", as even the induction cooker crt only work well with 500 to 600 watts of load, or higher.

  Here's a link to the TVS Zener diodes:
http://www.digikey.com/product-search/en/circuit-protection/tvs-diodes/655429?k=F586

  Igor has another new video that just came out yesterday, you may want to check that one out, also. He's always trying out different things.
After 268 videos, you'd think he would have hit on something special, if only by accident.

Hi Grum,

i cannot match the shown diagram with the video.
To me its looks like 2 different circuits, like where does this capacitive wire comes from/goes to?

Anyway, my guess is that you have an inductive coupling into your bulb.
The flyback is already DC (it has internal diodes), so running it through an external diode again will not add much.

And, those crocodile leads are not meant for HV, so please be carefull when using them in this situation!
Use pliers or something else to handle them

Just my 2 cents 

Regards Itsu

Dear itsu.

I can see what you are writing about so please see amended schematic below !! 

My "Capacitive coupling ??" was that loosely looped length of 3 core flex with the 13A plugtop on the end !! We tried various lengths of wire with varied results. I have not been able to try some Coax however !!

And thanks for the advice with regard to the clip leads. Been zapped several times already !!    Not a good idea for someone who has survived 2 heart attacks !!  But I think electricity runs through my veins anyway !! 

Cheers Grum.

Grum,

ok, that looks better, like in the video, one common ground.

My guess is that this 3 mtr wire is capacitively coupled to ground and therefor forming an parallel LCR with the filament induction of your bulb
Depending on how tight you couple the black wire to the HV it will vary the frequency and when it hit resonance of this LCR it fires up the bulb.

Something like shown in this drawing.


Who's next?


Regards Itsu

Dear itsu.

Your theory sounds good to me !!

Please see attached to verify. There was no connection to the other end  than the, dare I say the word ?? Aether !!     

Cheers Grum.

Interesting: After 1500x Kapanadze pages we are back to a light bulb connected to a spark gap and ground.

Thanks for the scope shots, is channel 4 the output, it looks like its putting out pulsed dc.
If it is it should be easy to smooth out, just thinking out loud, Im playing with the same driver but using a large flyback core.

Hi Dave,

CH4 (green) (and CH3 which is overlaid by CH4) is the Drain signal of one of the MOSFET's. CH3 (purple) is the other MOSFET's drain signal.
So we have CH1/CH2 gate signals, CH3/CH4 drain signals.
The output of the yokes secondary (to the bulb) is sign wave (in normal mode), not shown.

Regards Itsu