Re: Double humpin'

To: tesla-at-pupman-dot-com
Subject: Re: Double humpin'
From: Richard Hull <hullr-at-whitlock-dot-com>
Date: Thu, 07 Nov 1996 13:58:37 -0800
Tesla List wrote:
> 
> >From sroys-at-umabnet.ab.umd.eduWed Nov  6 22:30:49 1996
> Date: Wed, 6 Nov 1996 11:00:11 -0500 (EST)
> From: Steve Roys <sroys-at-umabnet.ab.umd.edu>
> To: tesla-at-pupman-dot-com
> Subject: Re: Double humpin'
> 
> On Tue, 5 Nov 1996, Tesla List wrote:
> 
> > All,
> >
> > I get the impression that some of our folks think that you get a double
> > hump or spliting of frequencies at tight coupling.  Double humping only
> > occurs in spark systems when we exceed the point known as "critical
> > coupling".  critical coupling has only a little to do with
> > actual inductive coupling (about 50%)
> >
> > If we throw a fixed gap of a fixed dwell/quench in a system, critcal
> > coupling occurs at some fixed coupling coefficient K=X.  If we have a
> > variable dwell/quench gap, and a fixed tight coupling, by varying the
> > dwell we can make the system go from  below critical coupling to well
> > beyond.  In short, critical coupling is a sliding point based on actual
> > inductive coupling and dwell/quench time of the gap's realizable
> > quenching ability.  In theory we can have a single frequency output (no
> > splitting) at k=.65.  This was the struggle in the early days of spark
> > transmitters in the 100KW-.5MW class.
> 
> It was my impression that the "double humping" occurring at critical
> coupling was dependent on the Q's of the coupled circuits.  Certainly the
> gap affects the Q of the primary, but I thought that the shorter quench
> times were more effective in allowing you to use higher couplings and
> still get the gap out of the way before the energy started transferring
> back to the primary circuit, rather than using the gap to actively
> modify the point of critical coupling (or is this a matter of semantics
> biting me in the a** again?).
> 
> Steve Roys, TCBOM.


Steve, 

Semantics is the culprit again,  The splitting of frequencies (critical 
coupling) occurs at a sliding point based on a broad range of goings on. 
 But, given good construction and a tight coupling, The gap dwell/quench 
time can alter this point.

Richard Hull, TCBOR