Re: AMRAD Spark Gaps

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

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

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


	
> 
> 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.

	No knowledge on the latter.  I don't have opinions about running with
hydrogen, although if the flow rate is high enough you may get
sufficient cooling to keep the thing under control, since I don't see
any other means of cooling.  By the way, what gap spacing are you
planning?  The essence of the quenched gap is to have the discharge take
place over between very small gap(s) of large area to keep the gas as
cool as possible and make the spark extinguish as quickly as possible.

> 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.

	The use of a fixed gap in series with a rotary is beyond my experience,
but perhaps some of the fellows who operate that way can make comments.

> Worth a try, I think.
> 
> Ideas, comments?
> 
> Cheers, and a merry christmas to all!
> 
> Finn Hammer

	Sounds like an interesting design and quite a lot of work.  Keep us
informed on progress.

Ed

P.S. Make a crude schematic sketch of the gap I have to help explain it
to those who may not be able to visualize the construction from my word
description.  It's a 76K gif file which I'll pass along to anyone who is
interested.