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Re: Triggered gap questions



Original poster: "Jason by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jasonp-at-btinternet-dot-com>

Mike,

> One thing I read is that the primary
> current passes 'through' the trigger electrode.  My question is, could the
> trigger electrode be positioned slightly out of alignment with the primary
> gap electrodes so the triggered arc would have to take a slightly 'bent'
> path?  This, if so, would seem to me to help alleviate heating and/or
> corrosion of the trigger electrode.
Not really - If you have a kind of setup as in a safety gap with the central
electrode as a trigger, thenyou will still get burning/corrosion/whatever/
The only way to not get corrosion on your trigger electrode, is not use one.
(Use a UV laser to trigger it, as they do in the deutches museum in munich
for their marx) The best way of minimising wear is to use tungsten for the
trigger 'ode.

>    It would seem that the trigger electrode could be made into a sharp
point
> and cause the ionization of the space between the gap electrodes to
provide
> the conductive channel to form more easily and not actually have the
primary
> current contact the trigger electrode at all(or very little anyway).
Good idea in theory - However in practice the electricity will always take
the path of least resistance, i.e. along the ionised air (which will be
attracted to the gap electrodes by the high gap potential) and through the
needle (which WOULD burn up).

> If the
> trigger electrode were positioned from below the primary gap electrodes,
the
> heat might also help 'move' the arc away from the trigger electrode.
Possibly, although over the time that we are talking about (a few uS) there
wouldnt really be enough time to create a Jacobs Ladder effect.

>  The first objection to this idea, I imagine, is that might argue that
this
> would effectively make the gap too wide and kill a NST, but if one placed
> another gap or two in series, the triggered gap could have a large
percentage
> length change, but the overall gap length would not change by much.
Having
> the series gaps would also seem to aid quenching as well.
> Comments?
The positioning of the trigger 'ode below the gap 'odes would not cause
misfiring unless the gap space was incorrectly set.

My thoughts on triggered gaps - The best way to make a triggered gap is to
use the multi segment SG design, and place the trigger across the first gap
like this:

OOOOO|O

so that once the trigger fires, the volts/gap increases (less inactive gaps
= more volts/gap) thus making the rest of the gaps fire in sequence, as
happens in a marx generator. This is in my opinion the best method.

Good Luck!
Jason

> Mike
>
>
>
>