Re: synch gap question (fwd)

---------- Forwarded message ----------
Date: Sun, 18 Jan 1998 08:50:04 PST
From: Mad Coiler <tesla_coiler-at-hotmail-dot-com>
To: tesla-at-pupman-dot-com
Subject: Re: synch gap question (fwd)

>---------- Forwarded message ----------
>Date: Fri, 16 Jan 1998 16:13:23 +0000
>From: wysock-at-ttr-dot-com
>To: Tesla List <tesla-at-pupman-dot-com>
>Subject: Re: synch gap question (fwd)
>> Date:          Fri, 16 Jan 1998 16:01:32 -0700 (MST)
>> To:            tesla-at-pupman-dot-com
>> Subject:       synch gap question (fwd)
>> From:          Tesla List <tesla-at-pupman-dot-com>
>> ---------- Forwarded message ----------
>> Date: Fri, 16 Jan 1998 08:55:41 PST
>> From: Mad Coiler <tesla_coiler-at-hotmail-dot-com>
>> To: tesla-at-pupman-dot-com
>> Subject: synch gap question

Dear Bill, all

Your explanation makes good sense too me. Unfortunately I am using a 
single 12kV 60 mA neon sign transformer. Again unfortunately I have 5 of 
these transformers and can only use one in my TC because of my primary 
capaicitors (60mA max). Soon I may finish my homade caps. Anyways, I 
wanted to use the synchronous gap because several coilers had got better 
results using a synch gap rather than static on a NST. I have also been 
thuroughly warned against using a nonsynch rotary gap on a NST, although 
several have done it with success. Basicaly, I am just trying to get the 
most out of this small coil. Maybee I should stop foolin around with 
this and concentrate on finishing my next coil.

Thanks for all the help,
Tristan Stewart

>Dear Tristan, all
>The paper I gave before ITS was 1991.  Others on the list have 
>made many comments about what is the appropriate level of
>a.c. power input where a coiler should consider a sync. rot. gap
>in place of any kind of series static gap.  I have always liked the
>idea of using static gaps with NST's as opposed to a rotary.  In
>your post, you did not mention the amount of operating current,
>so I have no idea if you are using a single 60 ma. unit or a number
>of parallel connected NST's.  I have found, (from personal 
>experience,) that I always obtained superior performance from a
>sync. rot. gap when I was using a non-saturable core transformer
>where the load current was >200 ma.  This implies however, that
>a series variable inductance (autotransformer as a series-
>connected inductance,) along with an additional autotransformer
>(connected as an autotransformer for variable voltage control to
>the H.V. transformer input,) be utilized.  There is a symbiotic
>relationship here; the two autotransformers, the non-current
>limited H.V. transformer, and the DWELL angle of the RSG.  And
>this relationship varies from one experimenter's setup and group
>of components, to another.
>You did not state why you wanted to go from your successful
>static gap to a RSG, using a NST (one or more.)   I believe part of
>the problem you are seeing is that since the NST(s) have a current
>limiting shunt, and since they were designed to work into (more
>or less) what you might call a "steady state" non-inductive load
>(neon tubing,)  that when you try to use any form of "forced"
>timed gap for the tank circuit, the NST(s) (to personify the
>situation,) "Don't know how to handle that condition."  
>If you are really enamoured with the idea of using an RSG,
>make it a high speed non-synchronous-type (where you are using
>NST's for the power source.)  You won't exceed the efficiency of a
>good static gap design, but you will have the "beauty" of an RSG
>running your system.
>As for my statements about a sync. rot. gap not firing on the peaks
>of each 1/2 sine wave, that comment applies only to the non-
>saturable core class of power supply transformers, supplying the
>tank circuit with a.c. power.  For example, if you had a pole pig,
>rated at 20 Kva, and you current limited its input to say, 12 Kva,
>and you "fired" only on the peaks with your sync. rot. gap, you 
>would have a lot of wasted input power, and have lost a lot of
>"time" not spent charging the tank caps to the highest usable 
>coulomb level for any instant of time.  If however, you rotate the
>index (dwell) of the firing times of your gap in this instance, to
>not fire directly on the sine wave peaks, but only along the rising 
>or falling skirts of the sine wave, then you will see more efficient
>"power processing" i.e. more a.c. 60 Hz POWER in: more r.f.
>current and higher r.f. voltage out.
>Bill Wysock
>Tesla Technology Research

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