Re: Next step-> Magnifier

To: tesla-at-pupman-dot-com
Subject: Re: Next step-> Magnifier
From: "Malcolm Watts" <MALCOLM-at-directorate.wnp.ac.nz> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Mon, 17 May 1999 22:19:51 -0600
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Hi Finn,

> Original Poster: Finn Hammer <f-hammer-at-post5.tele.dk> 
> 
> I tried to provoke racing sparks by lowering the secondary to K=0.2,
> but  without succes, the sparks just got longer, that`s all. :-) With
> the gaps set to 20kV, that`s 16,8 mm (0,66") in my gap, I just managed
> 90 " continous spark from breakout point to grounded rod. However, the
> coil seemed more well tempered than ever, no safetygap firings at all,
> and no self hits either. Also, breakout from the 12"prim. dia. toroid
> was now possible. Random breakouts: now _that_ makes the coil come to
> life for real! Unfortunately, I can`t lower the secondary any further
> without messing the base up, and since the national electricity museum
> has voiced interest in buying it, I don`t really want to do that.

If you increase your primary energy you will indeed get to the point 
where racing sparks occur, even with modest values of k. It is not 
difficult to do.

> My gut feeling about racing sparks is this: As the coupling is
> increased, the coil gradually takes on the caracteristic of an ordinary
> transformer, where the turns ratio rules. With a relatively low amount
> of turns like mine (800) I can then use a higher coupling than a coil
> with say 1200 turns, without exeeding the interturn breakdown voltage.
> 
> About magnifier:
> 
> I feel like taking on the challenge of building a magnifier system, 10kW
> pig and suitable rotary. In contrast to the classic TC, which is easy to
> make (anything goes, as long as it is in tune) the magnifier seems to me
> like a *black art*.
> Any help in establishing a fundamental understanding of its function
> would be much appreciated.
> 
> Cheers, Finn

Check the archives for posts by Dr de Queiroz on mag modelling. I 
have measured Ksys for magnifiers and found that in general, they are 
no different to the K's one would use for a two coil system. It isn't 
hard to make a free resonator system. I whipped one up on the 
benchtop the other night using off the shelf coils and tuning the 
primary to the resonant frequency of the secondary+extra system. Well 
I don't think it's hard or mysterious anyway.

Malcolm