Triggered gap proposal

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

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

Marc, Terry, All!

I would like to propose a triggered gap, which is easy to build, that
runs cool, while able to sustain the the strain associated with a coil
producing 5 feet streamers at the least.

First I would like to express my respect towards Metlicka Marc for
sticking so inexhaustably to the idea of using triggered gaps.

The gap that I am proposing is based upon an idea by Marc <Finnis, but
realized without the use of tungsten electrodes.

I have run the mentioned gap continously for more than 10 minutes
continously, and it only gets luke warm.

You can see it here:

http://home5.inet.tele.dk/f-hammer/triggergap.jpg

349K

It is really thrown together in a couple of hours, I was in need of a
gap, without a lot of time to build it in.

The parts can be bought locally, even scrounged if you have access to
electronic scrap, the heatsinks are commom in solid state amplifiers of
the 100W gender.

I beleive that it is the massive electrode bars in solid copper,12.5" by
3/8 inch crossection, combined with the heatsinks, that produce the
results: the thermal conductivity of the copper bars combined with the
thermal mass of them insure, that the electrodes are kept cool from the
instant they are under sparking condition, into continous operation,
where the heatsinks support the thermal emmissive properties needed to
keep the whole structure below 100 degrees centigrade.

No fan is neded, but perhaps it is desired at higher power levels.

The ignition coil has had the primary coil removed, and rewound after
the secondary has been sufficiently insulated, so that the coil is tied
to one end electrode and the center electrode. the triggered gap is able
to hold the whole voltage of the coil psu off on its own, whereas the
untriggered section is set to a distance which produces the voltage
needed for the sparklength desired.

Capping the electrodes with some tungsten would not hurt.

Cheers, Finn Hammer