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LAN_403

Mon Mar 27 2006, 11:37PM

Registered Member #256 Joined:
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Posts: 124

i am highly interested in making a sstc and i cant really understand what the google results mean, what is done to run a sstc? rectify mains? then feed mosfets to it? if i can get help understanding operation of sstc it would be greatly appreciated, btw i am gutting multiple electronic devices(TV, monitors, PC power supplies, what type of things can i pull out of these to possibly get a sstc going?

HV Enthusiast

Mon Mar 27 2006, 11:40PM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
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Posts: 3068

For good theory, check out Richie Burnett's tesla site (search GOOGLE), for good designs, check out Steve Ward's. I'm going to be publishing a detailed book on DRSSTC, both first and second generation designs (another variant of the SSTC) by early summer, so keep a look out for that as well . . .

Mon Mar 27 2006, 11:45PM

Registered Member #256 Joined:
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ii will be looking forward to that and will check out these sites, but help will likely still be needed so pllz do so! thank you

Mike

Tue Mar 28 2006, 12:01AM

Registered Member #58 Joined: Thu Feb 09 2006, 05:40AM
Location: Tri-Cities, Washington, US
Posts: 317

As far as I understand it, Solid State Tesla Coils use a halfbridge or Fullbridge of transistors (IGBT/Mosfets) to change the frequency of say rectified mains, while spark gap tesla coils use the firing spark gap to change the frequency, Sorry I can't explain it much better, I am sure there is someone much more knowledgable then me that could :P

Tue Mar 28 2006, 12:18AM

Registered Member #256 Joined:
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ive done sgtc and i would like to try this as well

...

Tue Mar 28 2006, 12:25AM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

Well...
A sgtc works by having a large cap that is resonant with the primary, so that when you use a spark gap to connect the two it resonates, and that transfers the energy from the tank cap to the secondary where it produces the streamers.

A sstc works by removing the tank cap and just driving the primary at it's resonant frequency (using 1, 2, or 4+ switches).

That is pretty much the difference...
Of course there are all of the other flavors, but even I don't quite understand some of those

So the normal scheme for a sstc is variac->brdge rectifier (possibly a filter cap)->swicth(es)->primary|secondary(sometimes a topload)

It is the switch bit that is complicated... Steve's micro sstc might be a good place to get started. That should give a solid 1" or a little more depending on how many fets you are willing to blow

good luck!

Tue Mar 28 2006, 12:27AM

Registered Member #256 Joined:
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Posts: 124

what is a good fet to use? i have pulled quite a few from electronics so i have many at my disposal also what is a gate driver and what does it look like?

Desmogod

Tue Mar 28 2006, 12:41AM

Registered Member #139 Joined: Sat Feb 11 2006, 11:01AM
Location: Perth, Western Australia
Posts: 358

Ok, without going into feedback based designs, the very simplest SSTC is usually just an oscillator feeding a signal ( @ Coils Fres) to a pair of mosfet driver chips. (One inverting, one non inverting) UCC37321 and UCC37322 are the ic of choice.
This in turn runs a Gate drive transformer, or GDT. (Google thedatastream for more info) The GDT then drives the gates of a pair (in case of a halfbridge) or in the case of a fullbridge, four MOSFET's.
These MOSFETs chop up (Usually) filtered DC and feed it to the primary coil.
It is essential that you have some pretty hefty MOSFETs for the job, IRFP460's are what I have in my halfbridge, and they seem to last ok. The size and power of your coil will dictate the semi's you use.
As stated, check out richie's site, thedatastream and both the steve's sites.
Once you have a basic oscillator driven oil running, you can then look at feedback based designs.
Hope this helps.

Tue Mar 28 2006, 01:25AM

Registered Member #256 Joined:
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Posts: 124

i will check out this idea and thanks for all the help so far everyone, i am pretty sure a majority of the fets i pulled are irfp460 type

Dr. Shark

Mon Apr 03 2006, 11:18AM

Registered Member #75 Joined: Thu Feb 09 2006, 09:30AM
Location: Montana, USA
Posts: 711

If you have difficulty finding some gate driver chips (I am sure I had!), you can order free samples of TC4422 from microchip.com

For your first attempt I would suggest you start small, with a single FET and antenna feedback (see Steve Wards MicroSSTC), this has the least part count, and there is not a lot that can go wrong.

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