[Prev][Next][Index][Thread]
Re: Gap Dwell Times (formerly: Beating Solved)
Tesla List wrote:
>
> > > Subject: Re: Gap Dwell Times (formerly: Beating Solved)
> > Subject: Re: Gap Dwell Times (formerly: Beating Solved)
> > > Subject: Re: Gap Dwell Times (formerly: Beating Solved)
>
> >From hullr-at-whitlock-dot-comWed Oct 2 22:50:02 1996
> Date: Wed, 02 Oct 1996 12:31:25 -0700
> From: Richard Hull <hullr-at-whitlock-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: Gap Dwell Times (formerly: Beating Solved)
>
> Tesla List wrote:
> >
> > > Subject: Re: Gap Dwell Times (formerly: Beating Solved)
> >
> > >From sgreiner-at-mail.wwnet-dot-comTue Oct 1 21:51:08 1996
> > Date: Mon, 30 Sep 1996 14:50:17 -0700
> > From: Skip Greiner <sgreiner-at-mail.wwnet-dot-com>
> > To: tesla-at-pupman-dot-com
> > Subject: Re: Gap Dwell Times (formerly: Beating Solved)
> >
> > Tesla List wrote:
> > >
> > > >From MALCOLM-at-directorate.wnp.ac.nzThu Sep 26 22:18:09 1996
> > > Date: Fri, 27 Sep 1996 08:13:59 +1200
> > > From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
> > > To: tesla-at-pupman-dot-com
> > > Subject: Re: Gap Dwell Times (formerly: Beating Solved)
> > >
> > > In reply...
> > >
> > > > I did some research this weekend, pouring through a Corum brothers
> > > > monograph and some old posts to this newsgroup and found out that the
> > > > optimal dwell is 1/(k*Fr), *not* 1/(2*k*Fr). In other words, the spark
> > > > gap should conduct for only 1/2 of the superimposed beat-frequency
> > > > envelope. Primary current peaks at that point, and maximum energy is
> > > > transferred into the secondary.
> > >
> > > I started from k approx dF/F, and ringup time = 1/2dF so you can see
> > > how I derived that. The problem when cutting the gap off (if you
> > > could) when Ip is maximum is that with k<1, most of the primary
> > > energy is coupled to the primary. I tried doing exactly this with the
> > > MOSFET gap and the spikes hit the roof. Virtually none of that energy
> > > was coupled to the secondary. The spikes in a real gap would have re-
> > > ignited it anyway. I wonder if they have actually tried doing this?
> > > I found the ideal dwell to be when the secondary was fully rung-up
> > > and the primary had virtually nothing left. Even then, quenching at a
> > > primary zero-crossing is a no-no because of spike generation. I sent
> > > some photos I took of this process to several people.
> > >
> > > Malcolm
> >
> > Hi Malcolm and all
> >
> > This is an extremely interesting thread. I am now getting confused.
> > Exactly what do you mean when you say that the secondary was fully rung
> > up? Is this when you believe that all of the energy is fully transferred
> > to the secondary from the primary? If so, how can you tell?
> >
> > Thanks
> >
> > Skip
>
> Skip,
>
> I can't speak for Malcolm's interpretation, but a system is normally
> considered fully rung up at the first maximum of the damped resonant
> wave. It is rung down at the end of the wave train of damped
> oscillations.
>
> A lot of folks think the primary rings are transferred to the secondary!
> Well,.... yes and no. If you do not quench your primary circuit arc
> quickly enough, yes! If you quench the arc at the first zero crossing of
> the primary volatge peak, no!
>
> Remember that the primary is a complete resonant circuit all by itself.
> The secondary is also a complete and separate resonant circuit unique to
> itself.
>
> Ideally, we want to dump the magnetic energy we have expanded out from
> the primary winding into the secondary. But, before the secondary has a
> chance to "talk back" or do an "inductive dance" with the primary, we
> want the primary circuit OPEN (it doesn't exisit as a current carrying
> path anymore) That is, there no longer exists a ringing in the primary
> circuit. The magnetic energy we sent out from the capacitor blast, now
> falls in on the secondary and the secondary is absolutely free to ring up
> and down without the primary system interacting with it in any way.
>
> This is ideal action according to a number of theoretical approaches as
> well as the Corums. The spectral purity of the secondary is preserved.
> I am not 100% convinced that this gives best spark. I am convinced this
> gives the best RF wave.
>
> Richard Hull, TCBOR
Richard and all
This brings up a question which has been on my mind for a long, long
time.
If we only want the primary to ring up for 1/2 cycle .... why is it
necessary that the primary and secondary be correctly tuned? I know this
to be true and you know that I continue to try to build a 1/4 wave
secondary but I still can't put it together. Why can't we just closely
couple the primary to the secondary and jam the power in? I guess I need
something physical to put picture what is going on. I will certainly
appreciate any light that the group can shed on this.
Skip Greiner