A method for Static Gap control for high BPS rates

[Jeg]

Hey guys..

I'd like to share with you a way for controlling a static spark gap.

Before a while i needed a method to substitute the motor-part for my discharge experiments. I tried a lot of ideas, but the following did the job very good and fit to my needs. It has some drawbacks but in general it takes off the definition of static spark gaps! I reached BPS rates as high as 50KHz until now with my current mosfet coil/transformer.

If you are interested i can upload some photos of the Mosfet transformer. It is just a big bobbin with one layer as primary, and 5-7 layers for secondary of AWG15 house wire.

The idea is to create a high negative time-short peak, to the spark gap electrode opposite to the discharge cap. If this peak is high enough compares to the DC HV, then you can calibrate the gap as it  won't fire just only with the cap. The negative peak, gives rise to a difference potential of Vcap+Vneg.peak and the gap explodes.

What you should care about is first of all the discharge capacitor. If it's too big, then the current that goes back to the mosfet can easily fry it!

If the secondary Mosfet/Tranformer, is too big for higher peaks, then the oscillation freq. during the discharge is getting smaller. If you use a smaller secondary for higher frequencies, then the peak voltage is getting lower and so the spark control is getting lower.

In any case, you have to balance between secondary turns, oscillation frequency, current, and electrode distance.

An other thing is that by this way, someone can create HV peaks but loaded with high current!!! Such a simple idea but with great potentials if its used right.

Thanks
Jeg

[TinselKoala]

This sounds like a great idea. I'm wondering about this simple variant: instead of the secondary winding, could you just use a simple iron rod core, and have the mosfet's output coil (the "primary") wrapped around that? IOW, I'm wondering if the simple magnetic field changing in the iron rod would control the spark gap, or does it depend on the transformer effect to produce an actual voltage pulse in the secondary?

[DilJalaay]

Good Work.
Keep going, i want to see your setup.
Thanks

[Magluvin]

Yes, more pics.     Im amazed that when the coil between the spark gaps gets a jolt of current, the control coil doesnt cook the fet.

Mags

[Jeg]

Hi@all 

I have to say that i am glad you like it cause i spent some months to find a good balance for my testing purposes. I made many air coil transformers and mosfet drivers trying not only to protect the mosfets but also to achieve my main goal which is the creation and collection of high quantities of zpe or radiant energy if you prefer, in the way Gray did it but with cheap equipment.

Well, Tinsel the secondary is a crucial part of the system as all the current is going to pass through it. Without it you will not have a high negative peak in the order of some thousands Volts to contribute to the gap breaking-down. I haven't used magnetic quenching yet but as far as i know, the B-field of the electromagnet has to be perpendicular to the spark path to push away the ions. An other issue with this iron path, would be the minimizing of the high frequency oscillation between coil and cap during discharge. This is just guessing and i am not sure as i haven't test it in this way.

When i'll return from my job i will post some photos to see it.

Magluvin, i took the most current out of it without burning the mosfets, when i isolated the different parts of the equipment. I mean, the MC1406 driver is isolated from the mosfet through a small toroid coil as Guyla show me the way in the MC1406 driver post. Driver has it's own pwr supply from two 12V batteries. Then, Mosfet side has again it's own Pwr supply independent from the driver and with no common connections. And finally, the secondary coil is on the air without connections with the other parts of the driver system, connecting only to HV cap. through the gap. This is my final setup, and as i told before of course it has drawbacks, and compromises has to be done. One compromise is the amount of current that you need to take out, in relation of course with your Mosfet's characteristics.

Tnks
Jeg