Re: Brush spark gaps

Tesla List wrote:
> >From tesla-at-america-dot-comThu Aug 29 22:05:05 1996
> Date: Thu, 29 Aug 96 07:43 EDT
> From: Bob Schumann <tesla-at-america-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Brush spark gaps
> I recently bought some huge carbon brushes
> at ane electronic surplus store. They have
> a flat surface of about 3" X 2".
> I was wondering if it is feasable to employ
> these as a spark gap. It seems to me that
> the surface could take a 'hit' very well.
> Bob Schumann


The problem with using Carbon (or Graphite) as electrodes is that the
resulting arc is extremely difficult to extinguish (quench). The carbon
vapor/particles formed by the arc cause the gap to easily re-fire,
allowing power transferred to the secondary on a 2-coil system to
transfer back to the primary. Carbon arcs can operate continuously at
relatively low voltages, making for a VERY bright light source for
searchlights and movie houses, but a very poorly quenching gap for Tesla

If you are going to try them out experimentally, carbon arcs produce
large quantities of carbon monoxide, and MUST be operated so that the
hot gases are forcibly removed from the area. Carbon monoxide is nasty
stuff - it's odorless, it sneaks up on you with little or NO warning,
and can kill you! Be careful...


-- Bert --