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tesla coil new aproach 120v sine generator straight to coil

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LAN_403

cavemen

Tue Nov 17 2009, 05:57AM

Registered Member #2008 Joined: Tue Mar 03 2009, 05:11AM
Location: USA, Frederick, MD
Posts: 118

After a not-so successful built of mozzili flyback driver,
(gave out a 5mm spark, doesn't work after laying on a shelf for a year, discuss it later)
i wanted to start kirlian photography

so i thought of a light device that can give me 1 million volts

It appears to look like some kind of high frequency coreless transformer and a voltage multiplier after that.

So i want to build a cheap, simple to build and durable device on that principle.
I want to elliminate step-down transformer to power the solid-state driver generator or a step-up trans to power a spark gap. Spark gap is so stone age.

I look at different books and websites. My good old Russian 1960's book gave me a clue, since it had a similar device in it. (First transformer was still there, had two small mighty vacuum tubes)

Well. I want to build a circuit like a sine-wave from here to stand the 120VDC or atleast 60Vspiked :

The coil will be the primary.

What radio component will you suggest as a "transistor"? I am looking for advice on what powerful amp/switch semiconductor to use.
How can I protect it from spikes and what frequency can i make this thing go up to?
Zenders to ground?

(So I know the capacitor value.)
I like Irf MOSFETS.
I don't know if they would work in this scenario with this voltage.

We live in the solid-state world.

I also conciser building such circuit with an inert gas-filled spark gap tube.
But I had never heard of such tubes running from as low as 120VDC.
Ant there would probably be spikes from the primary.

doctor electrons

Tue Nov 17 2009, 09:02PM

Registered Member #2390 Joined: Sat Sept 26 2009, 02:04PM
Location: Milwaukee Wisconsin
Posts: 381

Actually the spark gap is very far from stone age. Sophisticated in its simplicity i would say, and major league effective.
It is a bit unclear what you are trying to accomplish. Are you trying to build a tesla coil? I think you want
to build a tesla coil, if that is the case, you can check the tesla coil forum. Not sure about your interest in the oscillator circuit in that link.
The transistors are in fact transistors. Maby someone else can chime in to help you out. The 120v sine to coil thing is also a little misleading, 120vac is a sine wave. 120vdc is not a wave unless it is pulsed or otherwise modified by the addition of some frequency or harmonics, but it is surely not a sine wave.
Good luck with the project!

Hazmatt_(The Underdog)

Tue Nov 17 2009, 09:28PM

Registered Member #135 Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735

Actually, Base Driving the resonator is not a NEW approach, I've been doing it long before you joined the forum. The problem is getting the impedance to match and enough power into the coil to see anything useful. I've been making broadband amps for a while now, and I'm finally getting power numbers that work, and hopefully soon I will have some amp modules I can post here for sale.

If you do some digging you can find an article way back in the mid 90's from Electronics Now which has a half bridge driver that base feeds a Tesla Coil wound on a 5 gallon poly paint bucket as well. So this is not new. The trouble is getting at least 100V into the resonator so it can kick that up to something visable.

My purpose is to further characterize the coil. I know its extracted network and how it behaives at half a watt, but I want to see how that compares at 2-400W.

Stay tuned.

cavemen

Tue Nov 17 2009, 10:34PM

Registered Member #2008 Joined: Tue Mar 03 2009, 05:11AM
Location: USA, Frederick, MD
Posts: 118

i am definitely not claiming the idea for myself
------------------------------------------- ---------
I am looking for some generator that can "work in resoncnce with the coreless transformer.
I don't care if it is a gap or tranz.

I want it to run straight of rectified wall socket voltage to be cheap.

Not the 60hz.

Hazmatt_(The Underdog)

Tue Nov 17 2009, 11:36PM

Registered Member #135 Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735

If you want rectified high voltage out of the wall socket to be cheap you use a Crockfort Walton diode / capacitor high voltage multiplier, which has nothing to do with Tesla Coils.

If you want to feed a Tesla Coil with a Sine wave, then you need an amplifier, spark gap system, DRSSTC, VTTC, or other system.

doctor electrons

Tue Nov 17 2009, 11:59PM

Registered Member #2390 Joined: Sat Sept 26 2009, 02:04PM
Location: Milwaukee Wisconsin
Posts: 381

Thanks hazmatt! You obviously knew exactly what he meant!

cavemen

Wed Nov 18 2009, 01:45AM

Registered Member #2008 Joined: Tue Mar 03 2009, 05:11AM
Location: USA, Frederick, MD
Posts: 118

OK. Here is the engineering challenge.
I should've said this earlier.

I want to do kirlian photography. So I want to energize a conductive electrode for kirlian photography.

I am not good with electronics, started a lot of failing projects, so I want to make only one circuit and i want it to work.

1,000,000 volts DC can do the trick.

I want my digital camera to be in the electric field, insulated, triggered by a wooden mechanism so it won't get zapped.

I want my power supply to give me the least hazy and the brightest corona I can get.

120 volts to 1,000,000 volts using a CW multiplier to begin with would involve 1,000,000/120 * 5 components.

Should I build a voltage multiplier on top of a high voltage transformer that runs off 120VAC?

Neon sign trans for example. But that thing is awfully expensive.

The idea is 120VAC-> transformer that makes 10kv ac -> multiplier -> some screen

Can this be done?

Herr Zapp

Wed Nov 18 2009, 04:09AM

Registered Member #480 Joined: Thu Jul 06 2006, 07:08PM
Location: North America
Posts: 644

cavemen -

I think there may be some confusion about how high a voltage is used during Kirlian photography (technically, the process produces "photograms", since no camera or optics are used, and no image is projected on photosensitive material).

1 million volts is, well, absurd.

Typically, voltages of 3-12KV are used. The beauty of this process is in the intricate detail generated by tiny corona discharges forming on edges, points, and other physical features on the "subject". Excessively high voltage will simply obscure all the fine detail, yielding just a rather overexposed, shapeless "blob".

If you are really interested in creating Kirlian photograms, then there are many options for generating the required voltage: automotive ignition coil, flyback transformers, trigger transformers, voltage multipliers, etc.

Herr Zapp

cavemen

Wed Nov 18 2009, 04:28PM

Registered Member #2008 Joined: Tue Mar 03 2009, 05:11AM
Location: USA, Frederick, MD
Posts: 118

If i t only takes 3 to 12 kv than great.

However I had seen a website that showed how to use a transparent electrode and a digital camera for this purpose. Film might work better, though.

Tell me if you know more about this process.
Thanks.

I will stick with the flyback driver. Or a neon sign transformer than.

I am interested in high voltage so I will build other devices. Each for there own application.

Issue resolved.
Thank you.
If it really takes that low of a voltage.

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