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SSTC=Super Simple Tesla Coil?

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Dr. Dark Current

Sun Mar 26 2006, 08:09PM

Registered Member #152 Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384

I had this idea in mind for long time: How about using that "dimmer circuit" to drive a TC primary? Maybe you'll have to use a fast triac and high number turns on secondary, but thats still simpler than building a complicated SSTC driver or designing a high voltage tank circuit for a SGTC. I'll try to build one soon and see how it performs.
Any ideas if it should work and how? My goal is to produce the highest voltage the simplest way, so even if it would be inefficient and bad performing compared to a "standard" TC, as long as it produces higher voltages than flyback it is great. Has anyone tried that before?

J.M.

Marko

Sun Mar 26 2006, 08:22PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

DImmer works by chopping parts of each halfwave by triac and you get no higher frequency than 50Hz, just a bit ''deformed'.
Some use PWM ICs for control but they also put out too low frequency and uselles waveform.

Driving any kind of TC with light dimmer makes no sense.

Dr. Dark Current

Sun Mar 26 2006, 08:30PM

Registered Member #152 Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384

I think the capacitor in series with the primary would resonate with the primary, causing high frequency oscillations.
Even if not, and it will transform just by turns ratio, you can get for example: 10 turn primary, supplied with 300V peaks, and 2000 turn secondary (fine wire), thats 300/10*2000=60kV. Make 3000 turn secondary and you have 90kV...

Marko

Sun Mar 26 2006, 08:43PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

You have air - cored transformer with low coupling, dimmer would undergo a nice explosion for being shorted trough few turns of wire that represent diminutive impedance at 50Hz.

Adding capacitor in series wouldnt really make some kind of oscillation since SCR blocks it when it closes, so tought of using dimmer such way is just silly.

dan

Sun Mar 26 2006, 08:55PM

Registered Member #223 Joined: Mon Feb 20 2006, 06:42PM
Location: Ottawa, Ontario, Canada
Posts: 125

Triac's are used in light dimmers and are basically bipolar SCR's. They could be used in an OLTC if they weren't so slow and you could get one big enough. But yeah the simplest Solid state tesla coil is an OLTC using big IGBT's for switching.

EEYORE

Sun Mar 26 2006, 09:15PM

Registered Member #99 Joined: Thu Feb 09 2006, 06:10PM
Location: florida, usa
Posts: 637

Some flourescent light electronic ballasts have been used to directly drive flybacks...Cant get simpler than that...Ive seen suitable ones on ebay that will run over 100watts. What do you mean by saying anything that produces more voltage output than a flyback?Some flybacks produce voltages higher than tesla coils.

Matt

vasil

Sun Mar 26 2006, 09:35PM

Registered Member #229 Joined: Tue Feb 21 2006, 07:33PM
Location: Romania
Posts: 506

It is hard to believe that it would work, with the schema you have in mind...
Maibe...you can close the primary LC circuit through a dimmer, as here:

http://www.geocities.com/gemaria_ro/s33.html

but I think that the triac will be fryed at high frequency.

Coyote Wilde

Sun Mar 26 2006, 09:37PM

Registered Member #175 Joined: Tue Feb 14 2006, 09:32PM
Location: Sudbury, ON
Posts: 111

Instead of a TC, use your light dimmer to drive an HE ignition coil.
Put the IC in a blast-proof box, if you want to run without a current-limiting capacitor and get arcs that can be drawn out to 2'. Expect the dimmer switch to not last long... nor the iggy.

A motor run or microwave oven capacitor is adaquate for current limiting, but your output is going to drop severely.

Marko

Sun Mar 26 2006, 10:07PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

That what vasil showed is particulary an OLTC, but dimmer would never actually do right there.

It would not even chop the cap when it charges fully and it would blow at any higher powers simply because of overcurrent.

Putting IGBT in its place could from other side make a nice OLTC

Dr. Dark Current

Mon Mar 27 2006, 01:42PM

Registered Member #152 Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384

mattrg2 wrote ...

Some flourescent light electronic ballasts have been used to directly drive flybacks...Cant get simpler than that...Ive seen suitable ones on ebay that will run over 100watts. What do you mean by saying anything that produces more voltage output than a flyback?Some flybacks produce voltages higher than tesla coils.

Matt

Yeah, I knew someone will ask this. I've dismantled many old monitors just to take the flyback. But here's the problem: Most large flybacks, that are capable of outputting 80+ kV have built in HV capacitor, so they make a BANG! every second or so, it's too loud and the cap shorts out. The small flybacks that die at <50kV does not usually have that disadvantage, but doesnt output "fun" voltages.
Maybe I'm just not lucky in finding good monitors...

EDIT: Err... can be an OLTC made with a heavy duty relay

or SCR as mentioned above? (just another silly idea on a simple TC really.)

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