Re: triggered gap performance?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Malcolm Watts by way of Terry Fritz <teslalist-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi Peter,

On 15 Jul 2003, at 18:34, Tesla list wrote:

 > Original poster: "Peter Lawrence by way of Terry Fritz 
<teslalist-at-qwest-dot-net>" <Peter.Lawrence-at-Sun.COM>
 >
 > Colin,
 >        my tungsten-carbide gap has four gaps, I also have some parts for a
 > one-gap gap but have not put it together yet...  I have heard that a single
 > is better than multiple if you have tungsten or tungsten-carbide, but have
 > not tried it yet. Multi-gaps may require less often cleaning so if you are
 > using copper/brass/stainless a multi may require less maintenance, but I'm
 > not sure if there is any other performance reason for single verses multi.

There is a minimum conduction voltage associated with each gap at
some particular current. More gaps in series = more voltage drops.
Additionally wide gaps used in triggered gap systems have also been
measured to be lossier when running identical currents to narrow
untriggered gaps. I personally prefer to run single gaps as narrow as
I can get them (includes sync rotaries which actually close up during
conduction).

Malcolm

 > Perhaps someone else on the list can shed some light on this.
 >
 > -Pete Lawrence.
 >
 >
 > (ps, tungsten-carbide at high power probably has the same problem that the
 > 90% tungsten 6% nickel 4% copper "tungsten" EDM rod has, it usually has a
 > cobalt binder that will evaporate and erode quicker than pure tungsten,
 > but at these low powers (6~9kv) mine are holding up fine).
 >
 >
 >
 >  >
 >  >Original poster: "colin.heath4 by way of Terry Fritz 
<teslalist-at-qwest-dot-net>"
 > <colin.heath4-at-ntlworld-dot-com>
 >  >
 >  >hi pete,
 >  >             thanks for the info. i was going to build a lash up 
static gap
 >  >to tune first. but now ill put my effort into that.
 >  >how many gaps do you use? i was thinking of four or five!
 >  >cheers
 >  >colin
 >  >----- Original Message -----
 >  >From: Tesla list <tesla-at-pupman-dot-com>
 >  >To: <tesla-at-pupman-dot-com>
 >  >Sent: Tuesday, July 15, 2003 7:44 PM
 >  >Subject: Re: triggered gap performance?
 >  >
 >  >
 >  > > Original poster: "Peter Lawrence by way of Terry Fritz
 >  ><teslalist-at-qwest-dot-net>" <Peter.Lawrence-at-Sun.COM>
 >  > >
 >  > > Colin,
 >  > >        I too have been building "small" TCs (6kv, 7.5kv, and 9kv NST
 >  >supplied).
 >  > > at these low powers a static gap works just fine. I have built a rotary
 >  >gap
 >  > > but don't seen any advantage at these low power levels.
 >  > >
 >  > > tungsten or tungsten-carbide will make the gap last (essentially
 >  >indefinately
 >  > > at these powers) and not require periodic cleaning (copper, brass,
 >  >stainless-
 >  > > steel all do).
 >  > >
 >  > > a fan to blow the gap will make the most difference. I use a 
squirrel-cage
 >  > > fan from an old microwave oven.
 >  > >
 >  > > -Pete Lawrence.
 >  > >
 >  > >
 >  > >
 >  > >  > >
 >  > >  > >  > Original poster: "colin.heath4 by way of Terry Fritz
 >  > >  > > <teslalist-at-qwest-dot-net>" <colin.heath4-at-ntlworld-dot-com>
 >  > >  > >  >
 >  > >  > >  > hi all,
 >  > >  > >  >          im building a small coil. 2" secondary run off a 7.5KV
 >  >30mA
 >  > >  > >  > transfomer!
 >  > >  > >  > my question is will a sync triggered gap match the 
performance of
 >  >a
 >  > >  >rotary
 >  > >  > >  > gap at these low powers?
 >  > >  > >  > im assuming it will as at the low current quenching should be
 >  > >  >relatively
 >  > >  > >  > easy with an air blast!
 >  > >  > >  > ill be running at a 100bps (im in uk).
 >  > >  > >  > many thanks
 >  > >  > >  > colin heath
 >  > >  > >  >
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