Solid State Tesla Coil 3: The search for even more Power!

last updated:03 Dec 2003

All informations in this page are published free and are intended for private/educational purposes and not for commercial applications .

Solid State Tesla Coil W/ KiloWatt Power Driver

I've Got the Power! It won't be long before I will start experimenting with the Hutchison effect. With my new Kilowatt+ switching power supply, I can do some pretty amazing things with my tesla coils. Above is just one example, using my small coil. At high enough power levels, a strange bush like discharge will erupt from the toilet plunger cap (High Voltage terminal of the coil). Once this discharge appears, it will keep its form and move around the surface of the copper cap, much like it has a mind of its own. This is a very unusual discharge, the likes of which you will never see on a spark gap variety tesla coil. I found that some times the spark will not start by itself, and it will need a little help. This can be accomplished by bringing a grounding wire near the top terminal and drawing an arc, or by slightly chirping the frequency. For some reason, a chirped frequency produced a high instantanious power at the H.V. cap, and allows for the formation of a spark. (this is probably one reason why spark gap tesla coils are able to produce longer sparks than C.W. solid state coils can.)

Ok, here above are some example of the high voltage arcs I can draw off the small solid state tesla coil with the new kilowatt driver. The right hand picture is of the thru R.F. power going to the coil. I have measured continuous power levels greater than 1000W! This device is truly something else.. (BTW, if there is interest for such a device out there, My design for a simple surface mount circuit is nearing completion, And I may make this design available for sale as a kit, for all you mad scientist out there,in need such a nifty power driver unit...) Believe me, it will be a bargin also, if you consider how many expensive FET's you will go through, trying to design one...

OK Now If I put a pin point on top of the small tesla coil, I can produce some interesting streamers. These streamers are unusual, in that they are almost a cross between a flame and a high voltage electrical discharge. By the way, if you have a garage door opener, don't put it in your pocket, and stand next to this guy, while it is running at high power. Especially if the garage door is your only way out of your garage.. It was not fun! It took me about an hour to figure out how to get out of my own garage that night.., after I realized my opener didn't work any more.... Sounds like An EMP weapon in the makings??? What do you think??? Unfortunatly I was the victom...

Ok, Now this is my large 8.5 inch diameter coil, wound on a huge PVC pipe. This larger coil (with fairly large gauge wire) produces longer sparks and a much large radiated field. Much to my surprize, even 10-12 ft away from the coil, I would get a pretty good RF buzz, when I try to touch the Bird RF meter. You never quite expect to see Visible sparks coming out of your finger tips when you are trying to change the direction of those metal Bird elements. Anyway, I decided that measuring the RF reflected power, at that very point in time, was not that importain. The second picture is my primary coil, made with 8 turns of Radio shack speaker wire (large flate braided variety).

The interesting thing I discovered is that when using a solid state driver such as this, the primary no longer needs to be tuned using a capacitor. This is great, because the low loss capacitors can be fairly expnsive and are only good for one particular frequency (for a given primary coil). My set up is ultra broad band. I can excite several tesla coil resonance, just by changing the frequency on my oscillator. The condition for this to work well, is when the primary impedance is matched (close to) the impedance of the 50 Ohm transmission line I am using (RG-58). I measured input (D.C.) impedance to the driver element by measuring input D.C. current and voltage (impedances of 50 to 100 Ohms worked well, larger impedance mismatches gave lower power at the coil). AT higher frequencies, I use a 4 turn primary instead of the 8 turn coil. The right two pictures show the longer streamers generated by the larger 8.5" coil running CW. The orange light in the lower part of the right hand picture is a little neon bulb, I use to tune in my resonances..

Ok, Here is the second reason why spark gap tesla coils can produce longer sparke. They are pulse modulated. They run at high peak power and lower average power, where the solid state tesla coils I have shown up to this point are all run CW (with a large, high power, 110:250V transformer). These steamers above are produce by:

1. turning off the oscillator,

2. charging up a 2500V 100uF cap to 500-900V. (Note: My FETS are only good to 1000V), and

3. Suddenly turning on the oscillator...

and riiiip-pop an 8 in streamer comes ripping out the nail at the high voltage terminal. Remember, I am commanding every single RF cycle with my power driver, this is no resonance on the primary. If we assume a breakdown voltage of about 30kV/cm, then this coil is producing well over a one half of a MegaVolt! Unfortunatly, for some unexplained reason, after about 5 or 6 pulses, instead of a pop, there was a thud, which came from my power driver. This thud took out several of my high power FETS as well as some HV high power diodes that were not even directly in the circuit. At first I though I over-currented the FETS, But later I realized that, when the coil was run CW at high power, the oscillator became a little unstable. I believe the high power pulse may have caused the oscillator to glitch, and dump the full power of the cap, exactly where I didn't want it to. But this still does not explain the High Voltage diodes blowing out. I am going to investigating this phenominon much more thoroughly.

In closing, I have a new Tektronics oscillator FG504, and my equipment is at the point I can run two tesla coils at the same time. This will become part of my 'Zero Time Reference Generator' if you will ;-)... Very Soon I will start serious experiments with the Hutchison effect and PX. Below is a picture of the kilowatt solid state driver V4.1 that I used in these experiments

Copyright Information

Unless otherwise noted, all materials at this site (including without limitation all text, html markup, graphics, and graphic elements) are copyrighted ), 2002 by Reginald L. Jaynes. The material available through this site may be freely used for attributed noncommercial educational purposes only. We ask that due credit and notification be given the author.  

All materials appearing on this website may not be reproduced, stored in any retrieval system, or used in any way for commercial purposes without the express prior written permission of the copyright holder.  

Disclaimer: The author assumes no liability for any incidental, consequential or other liability from the use of this information. All risks and damages, incidental or otherwise, arising from the use or misuse of the information contained herein are entirely the responsibility of the user. Although careful precaution has been taken in the preparation of this material, we assume no responsibility for omissions or errors.  

HOME

Send e-mail to: dr_jaynes@hotmail.com