[Prev][Next][Index][Thread]
Re: Museum Coil Revisited Subject: Re: Museum Coil Revisited
Tesla List wrote:
>
> Subscriber: FutureT-at-aol-dot-com Thu Jan 2 23:15:06 1997
> Date: Thu, 2 Jan 1997 20:34:01 -0500
> From: FutureT-at-aol-dot-com
> To: tesla-at-pupman-dot-com
> Subject: Re: Museum Coil Revisited
>
> In a message dated 97-01-02 02:57:38 EST, you write:
>
> <<
> Subscriber: bert.hickman-at-aquila-dot-com Wed Jan 1 21:43:31 1997
> Date: Wed, 01 Jan 1997 10:38:36 -0800
> From: Bert Hickman <bert.hickman-at-aquila-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: Museum Coil Revisited
>
> Tesla List wrote:
> >
> > snip
> > << > The relatively radical approach used by Cox caused me to take a
> another
> > > look at this aspect of coil design. It looks like Cox'es grounding
> > > approach may be the best, at least for Museum coils!
> > >
> > > Isn't that the Oudin Coil scheme?
> > >
> > > 73, Ira
> > >
> > >" Yes, although there's some controversy over just _who_ should be
> > credited with this configuration. There are some who would say that an
> > "Oudin Coil" is also a minor variant of a Tesla Coil, and Oudin should
> > not be credited for what is largely Tesla's work. The reason this
> > configuration is somewhat "radical" today is that it goes against the
> > conventional wisdom on how 2-coil TC's should be constructed from a
> > safety and EMI standpoint, not that it is a brand new approach."
> >
> > >Safe coilin' to you, Ira!
> >
> > -- Bert --
> > >>
> > I've never used a separate ground for my secondary coil. I always ground
> one
> > side of my pri. tank, except in neon-sign systems. I haven't had any
> > problems with arcing outlets, etc. Never gave it too much thought since I
> > was busy with other coil aspects, but these posted comments are
> interesting,
> > never realized this hook-up was so rare and disliked.
> >
> > I thought also that capacitance between pri. and sec. was to be avoided as
> an
> > operating loss?
> >
> > John Freau
>
> >You bring up an interesting point! I had "assumed" that the
> >configuration of tieing one end of the primary to the secondary was
> >relatively rare, based upon the excellent design guidelines that Richard
> >Quick and others have provided on the Tesla site or in previous BBS and
> >Tesla List postings. I think the main objection was one of safety - with
> >the primary floating, there was no direct connection between any portion
> > of the 60 Hz HV, or high-power primary RF section, and the secondary. If
> >the common connection to ground were to become open or degrade, there
> > was at least less of a chance that the entire secondary would become
> >"live" with high voltage at 60 Hz. However, other bad things would
> >probably happen if you had an open the secondary base ground...
> >BTW - do you ground the innermost turn or the tapping point?
>
> > Primary-Secondary capacitance does not usually operating losses, unless
> > you're overcoupled and seeing heavy corona breakout between the two.
> > However, to the extent that higher capacitance effectively increases the
> >coil self-C or toroid capacitance, it can have the impact of reducing
> >coil output voltage a bit (all other things remaining the same). Is
> >there another loss you're thinkning of?
>
> > Safe coiling to you!
>
> -- Bert --
> >>
> Bert,
>
> I ground the inner primary turn in the hope that this will help to prevent
> corona, flashover, and losses. The capacitive losses I refered to are the
> ones you mentioned. I suppose the separate sec. ground is safer. BTW, what
> is the TESLA SITE that you mentioned? BTW, I'll get the specifics from
> Lou Balint concerning his oil-magnifier and oil tuning cap.
> Happy Coiling!
>
> John Freau
John,
The site run by Kristian Kristian Ukkonen at:
ftp://nic.funet.fi/pub/sci/electrical/tesla/
Lots of good info, archives from the Tesla List, pictures, etc...
Happy searching!
-- Bert --