From: FutureT@aol.com
Date: Mon, 6 May 2002 16:47:30 EDT
Subject: Re: [TSSP] Secondary voltage stress factor
--part1_144.e13e5ac.2a0845e2_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 5/6/02 2:11:00 AM Eastern Daylight Time, tesla123@pacbell.net writes: > > Q to all: Do racing arcs tend to occur before topload breakout, > > as the power is turned up, or do they appear at the same time? > > I think I may have asked this before, perhaps someone could > > remind me? > > Paul, Generally, racing sparks will occur only at or near full power in most cases. My TT-42 coil is coupled at only about k = 0.11, but it's very close to creating racing sparks. This is probably because the coil is somewhat short for the bang size. High breakrate coils and tall coils can probably coupled up tighter, for a given input power. In some experiments I did with a different coil, I tried using a 12 point series quenching rotary gap, hoping it would permit a somewhat tighter coupling, but it didn't help. It didn't help the quenching much either. In that test, the racing sparks raced all the way between the toroid and the bottom of the secondary when I tightened the coupling. The racing sparks had the look of creepage sparks over an insulator. This coil was wound with a PVC insulated wire, which seemed especially plagued by racing sparks. In other experiments, the static gap I was using heated up after awhile, and the racing sparks got much much worse. Perhaps the quenching was very bad. I didn't investigate it any further. Cheers John --part1_144.e13e5ac.2a0845e2_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 5/6/02 2:11:00 AM Eastern Daylight Time, tesla123@pacbell.net writes:
> Q to all: Do racing arcs tend to occur before topload breakout,Paul,
> as the power is turned up, or do they appear at the same time?
> I think I may have asked this before, perhaps someone could
> remind me?
Generally, racing sparks will occur only at or near full power in
most cases. My TT-42 coil is coupled at only about k = 0.11,
but it's very close to creating racing sparks. This is probably
because the coil is somewhat short for the bang size. High
breakrate coils and tall coils can probably coupled up tighter,
for a given input power. In some experiments I did with a
different coil, I tried using a 12 point series quenching rotary gap,
hoping it would permit a somewhat tighter coupling, but it didn't help.
It didn't help the quenching much either. In that test, the
racing sparks raced all the way between the toroid
and the bottom of the secondary when I tightened the coupling.
The racing sparks had the look of creepage sparks over an
insulator. This coil was wound with a PVC insulated wire,
which seemed especially plagued by racing sparks.
In other experiments, the static gap I was using heated up
after awhile, and the racing sparks got much much worse.
Perhaps the quenching was very bad. I didn't investigate
it any further.
Cheers
John --part1_144.e13e5ac.2a0845e2_boundary--
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.