Re: Laser Triggered Spark Gap

To: tesla-at-pupman-dot-com
Subject: Re: Laser Triggered Spark Gap
From: "Doug Brunner" <dabrunner-at-earthlink-dot-net> (by way of Terry Fritz <terryf-at-verinet-dot-com>)
Date: Tue, 03 Nov 1998 18:59:20 -0700
Approved: terryf-at-verinet-dot-com
I just finished some research on triggered gaps, and it looks like laser
diodes from laser pointers would not work for triggered gaps. UV light is
apparently the factor in ionizing the gap. Maybe a UV fluorescent tube?

           --Mr. Postman (Doug Brunner)
                <dabrunner-at-earthlink-dot-net>
-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Tuesday, November 03, 1998 2:57 AM
Subject: Laser Triggered Spark Gap


>Original Poster: "Steve Young" <youngs-at-konnections-dot-com>
>
>To fellow sparkers,
>
>This list has a lot of discussion about spark gap performance, quenching,
>etc., which certainly is valuable and needed.  For static gaps, discussions
>seem to indicate quenching is improved for wider gaps.  But a point is
>reached where the gap is too wide for spark initiation.  Thus the need for
>a means to "help" a wider gap initiate a spark.
>
>Occasionally the use of triggered spark gaps is mentioned, but the thread
>soon dies.  I would think this is an area for experimentation which could
>yield a LOT of benefits.  For one thing, the bps could be under our precise
>control simply by varying the trigger frequency.  If one chose to lock the
>trigger frequency to the AC line frequency and adjust the phase
>relationship, one would in effect be able to duplicate the performance of a
>RSG without having to mess with high RPM balanced rotors, etc.  Having the
>gap fire when WE want it to instead of when it can no longer resist firing
>itself would make for much better control and scope pictures for some of
>the other testing Terry and others are doing.
>
>The various triggering mechanisms have been touched on in this list.  These
>can range from pulse generator driven ignition coils to lasers.  My
>experiments with SCR driven crummy ignition coils indicates they are good
>for break rates up to at least 800 bps.  I don't know how the good GM
>ignition coils perform at higher break rates - anyone have some experience?
>
>
>Lasers would have the advantage of being able to simultaneously trigger a
>bunch of aligned series gaps by aiming the beam through all the gaps.  I
>suspect some Marx generators are fired that way.  But where can the
>cash-strapped experimenter find a suitable laser which can sufficiently
>ionize the air to initiate spark breakdown?  The only potential cheap
>sources I am aware of would be to use a $15 laser pointer in a pulse mode.
>Would this work?  Specifically, can the laser diodes handle microsecond
>pulses of a much higher energy without self destructing?  If so, could they
>produce enough pulse energy to trigger spark gaps?  If so, what would the
>pulse width and peak power need to be?  Does anyone know what the laser
>diodes used for tattoo removal, etc. cost and where to get them?
>
>In summary, isn't it time to move toward triggered spark gaps for
>disruptive TCs?
>
>Thanks in advance for your comments.
>
>--Steve
>
>
>