Kapanadze Cousin - DALLY FREE ENERGY

[Hoppy]

I have attached a waveform taken C/E (x10 probe on collector). This waveform fully closes the transistor using a totem pole driver (NPN / PNP pair BC546 / 556) and equalises the rise and fall times. I'm currently using a 1nf nano timing capacitor. Like Itsu, I'm not getting a very high voltage pulse across the DSR diode with 50R termination.

Regards
Hoppy

[verpies]

I have attached a waveform taken C/E (x10 probe on collector). This waveform fully closes the transistor using a totem pole driver (NPN / PNP pair BC546 / 556) and equalises the rise and fall times. I'm currently using a 1nf nano timing capacitor. Like Itsu, I'm not getting a very high voltage pulse across the DSR diode with 50R termination.

Well, 600ns is most likely too long forward pumping time for the DSR Diode.

I am happy for you that you can fully close the BJT transistor at 65V V_CE but voltage waveforms are not very informative (unless the load is resistive, the voltage tells us only what should happen - not, what actually happens in a circuit).
What is the current through the primary of your transformer?  At what current does the core saturate ...and after what time? 
What is the current through your DSR Diode?

And most importantly - does the saturation happen after half-a-cycle of the secondary RLC circuit's self oscillation period?

[itsu]

@all,

i removed my ground lead from my scope probe, but the signal looks the same (bad).
Then i changed to a carbon 1 Ohm resistor as csr and now the current has a different shape peaking to 15A.
Looks better to me, but points to a much earlier saturation of the toroid (around 20V).

Video here: http://www.youtube.com/watch?v=Ju4hFJdYN78&feature=youtu.be

I received my ordered toroids K7x4x2 and 10x6x4 yesterday.
Made 6/12 turns windings on them and measured this:

OD 7, ID 4, Th 2
L  6t =  30uH
L 12t = 133uH

OD 10, ID 6, Th 4
L  6t = 11uH
L 12t = 77uH (not sure why the 1:4 ratio is lost here, probably my meter has problems with this low inductance)

Video here: http://www.youtube.com/watch?v=zWYgkxRMXb4&feature=youtu.be

Regards Itsu

[Hoppy]

Well, 600ns is most likely too long forward pumping time for the DSR Diode.

I am happy for you that you can fully close the BJT transistor at 65V V_CE but voltage waveforms are not very informative (unless the load is resistive, the voltage tells us only what should happen - not, what actually happens in a circuit).
What is the current through the primary of your transformer?  At what current does the core saturate ...and after what time? 
What is the current through your DSR Diode?

And most importantly - does the saturation happen after half-a-cycle of the secondary RLC circuit's self oscillation period?

Top trace of attached photo 11 is voltage C/E. Lower trace is C/E current taken with a 0.1R CSR. Probe x10.

Photo 12 shows transformer primary current taken with 0.1R CSR. Probe x10.

Waveforms are messy. Will have to re-build!

Regards
Hoppy

[verpies]

I removed my ground lead from my scope probe, but the signal looks the same (bad).
Then i changed to a carbon 1 Ohm resistor as a CSR and now the current has a different shape peaking to 15A.

There should not be any difference in the current waveform shape between 1Ω and 0.1Ω resistors - only a difference in amplitude.
The unipolar current shape is a more correct shape so it seems that you correctly put you money on pt.2.
So, how much do I owe you?

Looks better to me, but points to a much earlier saturation of the toroid

That's not surprising. According to the attached scopeshot, this core saturates at 800mA. With 6 turns this means that the core saturates at 0.133 AmpTurns (AT)
Before the saturation, the slope of the green line is 700mA/μS (if the supply voltage (+V₂) was known the green slope most like would calculate to the 173μH self-inductance of W1 that was measured before with the inductance meter).
According to the scopeshot attached below, it takes 800ns for the core to saturate and after that point in time (the blue point) the slope of the blue line increases to 14A/μS which is 20x more than 700mA/μS, but that's still far away from total saturation, (full saturation would yield a >60x steeper slope). Apparently the core does not have a square BH curve and does not saturate abruptly.

The bad news is that this 800ns saturation time is too long for the forward pumping of the DSR diode.
In order to shorten the saturation time for this core, you must:
1) increase +V₂, or
2) increase the W1 turns, or
3) add a 3rd winding biased with DC current (and regulated with a 1kΩ potentiometer in series with 10Ω resistor).


What is surprising is that the KT926A conducts 15A current with 816mA of base current.
The flyback diode has the bear this current when the KT926A turns OFF (It's a good thing that it's pulsed rating is much higher than the 6A max forward current rating).