Re: Hi Power Discharge "Disruptive"

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com>

Hi,

At 05:32 AM 11/6/2004, you wrote:
>Hi Guys,
>
>I've been interested in 'Tesla' coils for about  7 years now since I first 
>picked up a book called "The fantastic inventions of Nikola Tesla".  I 
>have a degree in Electronic + Electrical Engineering so I have some idea 
>of how to build a coil.

Cool!


>I am a little concerned about the standard Tesla coil that everyone is 
>building as it does not appear to follow the models in the original 
>patents.  i.e. people still seem to like the idea of  using  an  LC 
>circuit for energizing the primary, where the capacitor is after the spark 
>gap and in parallel with the coil primary, thus producing a tank 
>circuit.  Tesla never only ever did this when working with AC and it had 
>nothing to do with 'Disruptive Discharge' which I believe is the main 
>principle of the Tesla Coil.

What?  I guess I don't get your meaning there....

>What should happen is a fully charged capacitor should discharge all of 
>its energy in to the coil in one burst via a spark gap.  Once discharged 
>the spark gap should close stopping any LC oscillations.  The process 
>would then be repeated with the capacitor fully charged again.  Is this 
>what you guys do?

Yes!!  Breaking the gap open after the energy is transferred to the 
secondary is known as "quenching".  Sometimes easy, sometimes not ;-)


>Also everyone seems to be using rectangular shaped coils, where as Tesla 
>used cone shaped coils as shown in the patient below:-
>
>http://www.pbs-dot-org/tesla/res/593138.html

The cone coils have a bit more linear voltage distribution, but now days 
with modern materials and all we just don't worry about it.


>Has anyone done experiments with a cone shaped coil and a pure disruptive 
>discharge with no LC oscillations?  I think one of Teslas objectives was 
>to completely eliminate all possible LC and focus purely on disruptive 
>discharge.  Also Tesla gave up on using  motor driven rotary spark gap 
>devices as they were too slow, instead he used a strong magnetic field and 
>air blasts to 'quench' the spark as soon as the current discharged from 
>the capacitor started to drop.  I can't find a link right now, but he 
>insulated an electromagnet from the spark gap using mica.  i.e. the spark 
>discharged through a hign magnetic field, greatly reducing its puls duration.

I am not sure that ever worked real well.  He ended up using mercury 
dissruptors which are a bite too poisonous for the average person.  But a 
rotary sync gap does fine.


>Has anyone tried these designs out yet as his articles say the resultive 
>'spark' effects on the primary are more like 'fire' and exhibit different 
>colors and shapes to standard HV air breakdown sparks.  i.e. He said they 
>were smooth and flowing and more gentle.
>
>I would very much appreciate it if anyone could let me know if they have 
>seen anything other than standard 'lightning' sparks.

Tube coils have odd spear like discharges with a cork screw edge to them.

http://research.microsoft-dot-com/~swinder/sparks/vac_images2/pic00026.jpg

Some ball top loads make a "hydra effect" with a solid spark shaft with 
streamers off the end, but that is super rare.


>Hope to hear from someone soon and I am delighted that this forum exists 
>as I believe Tesla was a genius and none of us mere mortals have the 
>slightest idea of what he was thinking when submitting these designs.

See these too:

http://hot-streamer-dot-com/TeslaCoils/MyPapers/modact/modact.html

http://hot-streamer-dot-com/temp/pn2511.pdf

http://hot-streamer-dot-com/temp/pn1401.pdf

Cheers,

         Terry



>Thanks
>
>Chris Rutherford