Ghazanfar Ali Generator - Utlilizing trapped energy

[forest]

Well, here is how it should work in my opinion. Mosfet switch currents at 50V level, but across mosfets are very fast bi-directional transient supression diodes , let's say we put a transil for 100V. It will conduct happily when voltage rise above 100V between D-S of mosfet. Here you see IMHO that this is maybe what Tesla wanted to find : switching large currents and HV in the same time.Large currents flow throught mosfet, while higher voltage currents flow through transils. It's just my theoretical idea. At least we must find why this set of mosfets works in simulation and not others. I would like to simulate 1.5KE transils but I'm not experienced in SPICE to write model for it.
Again, I think that very long running blocking generator with large currents circulating and not supressing HV is enough to get OU, just one step behind the success.

[forest]

Question: what is the bulbs resistance ? I cannot get 100V bulbs here ,only 230V.

[gyulasun]

Hi  forest,

Please help me understand what you really mean...  What shall I understand under your term 'high voltage current'?  Is it a current caused by high voltage when a certain HV limit is exceeded? 
If yes,  than what causes the current that the MOSFET switches?  The 50V you defined? 
So you have circuit where there is a controlled MOSFET switches a 50V voltage level and then there is the transil diode which switches at the say 100V level,  right?  Here I ask the 100V voltage level is created due to the switching of the 50V?

It would be good you show the link you already referred to above how the circuit might look like or just draw such.

Gyula

Well, here is how it should work in my opinion. Mosfet switch currents at 50V level, but across mosfets are very fast bi-directional transient supression diodes , let's say we put a transil for 100V. It will conduct happily when voltage rise above 100V between D-S of mosfet. Here you see IMHO that this is maybe what Tesla wanted to find : switching large currents and HV in the same time.Large currents flow throught mosfet, while higher voltage currents flow through transils. It's just my theoretical idea. At least we must find why this set of mosfets works in simulation and not others. I would like to simulate 1.5KE transils but I'm not experienced in SPICE to write model for it.
Again, I think that very long running blocking generator with large currents circulating and not supressing HV is enough to get OU, just one step behind the success.

[gyulasun]

Question: what is the bulbs resistance ? I cannot get 100V bulbs here ,only 230V.

From this schematic, the bulb has 100W power rating at 100V,  hence R=V² / P=100 Ohm (when it lights with 100W power of course).

http://www.overunity.com/11961/ghazanfar-ali-generator-utlilizing-trapped-energy/msg311553/#msg311553 

Just use  some power resistors in series and/or parallel combination to have a few watts rated 150 Ohm or higher load.
Use a full wave bridge plus a puffer capacitor at the device output and terminate the puffer capacitor with the load resistor and measure the DC voltage across it to estimate the dissipated power.

[Rosemary Ainslie]

Hi Rosemary,

A  Zener diode is not designed to switch quickly if you mean that switching speed (what is generally specified for switching type diodes)  is involved.  Normally, Zener diodes switching speed is not defined because their purpose is to have a very steep voltage-current characteristic in the reverse direction so that the current should change abruptly once the Zener voltage limit is exceeded.



Re on avalanche type MOSFETs:  please read this paper here in Pages 4, 5 and 6,  it is nicely explained:   http://www.irf.com/technical-info/appnotes/an-1005.pdf

Putting it briefly:  Avalanche effect can occur when the maximum drain-source voltage (specified for a MOSFET type)  is exceeded.   And there are certain power MOSFET types where the manufacturer designed the MOSFET to keep the avalanche current under a certain control so that the device should survive an avalanche current value,  once it is started,  where some other MOSFET types would surely self-destruct.
Here is the data sheet for the IRFPG50 power MOSFET, please see the second line in the feature column on the top of the first page, it says: Repetitive Avalanche Rated.
http://www.irf.com/product-info/datasheets/data/irfpg50.pdf   
This means that  maximum  6 Amper drain-source current is allowed  at a certain pulse width and at a certain junction temperature when the drain source voltage is higher than 1000V, (or  it can be less than 1000V but the avalanche current has already started due to a little overdissipation) see also Figure 11 in the data sheet.
I hope this helps, this is my intention. 

Gyula

PS  Ali,  sorry for such seemingly off topic mails in your thread, hopefully you undertand the goal -from my part at least- is to help the level of this discussion be as scientific as possible.  Looking forward to seeing further news from your great setup.

Thanks Gyula.  Very clearly explained and much appreciated.  I thought that avalanche was the same thing as a parasitic oscillation.  Clearly lots to learn.

Kindest regards,
Rosemary