Re: AMRAD Spark Gaps

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

Original poster: "Finn Hammer by way of Terry Fritz <twftesla-at-uswest-dot-net>" <f-hammer-at-post5.tele.dk>



Tesla list wrote:
> 
> Original poster: "Ed Phillips by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <evp-at-pacbell-dot-net>
snip

>  After looking at some of the workmanship on different web
> sites, think this would be childs' work for some of these guys, although
> perhaps they aren't interested in such low power operation.
snip

> Ed

Ed, all!

Who says low power?

I have been interested in this construction (the original AMRAD) for
some time, and I think I will have a go at it, since it seems that some
contemporary experience with quenching hydrogen gaps is needed.

The construction that I intend to use is seen below in ascii

     Please view in a fixed-width font such as Courier.


          ___________________      _____________________
         |                   |     |                    |
         |                   |     |                    |
         |                   |_   _|                    |
         |      ______         | |         ______       |
         |_____|      |        | |        |      |______|
   *************      |________| |________|      ************
   *           *       ___________________       *          *
   *************      |                   |      ************
         |     |_   __|                   |__   _|      |
         |       | |                         | |        |
         |       | |                         | |        |
         |      _| |__                     __| |__      |
         |_____|      |                   |      |______|
   **************     |___________________|      ************
   *            *      ________   ________       *          *
   **************     |        | |        |      ************
         |     |______|        | |        |______|      |
         |                    _| |_                     |
         |                   |     |                    |
         |                   |     |                    |
         |___________________|     |____________________|

The bigger holes in the endplates are threaded, to accept pipe fittings
for the hoses that deliver/dispose of the hydrohen gas. The hydrogen
then flows at a modest rate from the one end, radially out in the first
gap, trough the holes in the releif grooves on the center disc, and
radially _inwards_ on the second gap, and exits from the center hole on
the top endplate.
Of course a larger amount than 3 plates could be used.
Since the gap is mildly overpressurized, the gaskets don`t need to be
particularly tight, so I will probably just use epoxy/glass laminate.
The electrode discs will be turned from solid copper bar stock, And it
would be a small extra effort to turn grooves in the surfaces that meet
the spacer rings, which could accept thin *O* rings, if tightness should
turn out to be a necessity.

If I should deside to run the gap with alcohol derived hydrogen, this
would probably be the better solution, although I am a bit concerned
about the extra "stuff" that is generated this way.

Jim: what is this extra "stuff" and can it cause problems?

Tying the stack together:
3 or more epoxy/glass rods, with stainless helicoil thread inserts in
each end, will act as both radial allignment as well as axial tension
members.

Perhaps a modest amount of static hydrogen gap in series with a rotary
will enable the coil to quench the gap at the first notch, in
combination with the right coupling factor. For example, if a total of,
say, 1/5th of the gap voltage is across the quencher, the rest across
the low loss rotary, perhaps only a small increase in gap loss will be
added, and perhaps a better total efficiency will be the net result, due
to only one transfer envelope.

Worth a try, I think.

Ideas, comments?

Cheers, and a merry christmas to all!

Finn Hammer