[Prev][Next][Index][Thread]
Re: Rotaries and quench, was 12kV, 30ma neon TC specs (42" sparks)
From: FutureT-at-aol-dot-com[SMTP:FutureT-at-aol-dot-com]
Sent: Monday, September 08, 1997 4:35 AM
To: vince-at-wino-dot-com
Cc: tesla-at-pupman-dot-com
Subject: Re: Rotaries and quench, was 12kV, 30ma neon TC specs (42" sparks)
In a message dated 97-09-08 00:16:02 EDT, you write:
<< >> sync-gap....Special series quenching rotary, 8 spinning and 8 fixed
> >> electrodes. Gives 120 breaks per second. ( a good vacuum quenched,
> >> cylinder gap...multiple static...should work about as well, maybe
10%
> >> less spark).
> Could you explain your "sync gap". Are the eight gaps connected in series,
> as with a normal Static gap, and the spinning just helps quench ?? Or is
> this some combination of a rotary gap and a static gap ?? I was warned
> against running a rotary gap on a neon ??
>snip>
> Thanks,
> Vince
>>
Vince, All,
Many issues here.
The synchronous rotary gap that I use is the same as the series
rotary gaps used by Richard Hull, and Ed Wingate on their magnifiers,
except for two differences; my gap is synchronous, and the electrodes
are arranged in two clusters so that the gap fires only twice for each
revolution of the rotor. If the gaps were not arranged in clusters, then
the gap would fire based on the number of spinning and stationary
electrodes, for instance Richard's gap fires 8 times per revolution,
because it has 8 spinning and 8 stationary electrodes. (In reality,
some firings will be skipped because the gaps will present at too
low a voltage at times, depending on where it presents in time or
position along the 60Hz input sine wave.)
In a series rotary gap, every spinning elecrode has a stationary
electrode that lines up with it when the gap fires. The gaps are
wired in such a way that the spark snakes its way though all the
gaps every time the gap fires. Thus, the rotary gap incorporates
a series gap in its nature -- in its design. But there is no actual
static gap in the traditional sense. It is strictly a rotary, but the
spark snakes through many gaps in the rotary. (It's a little hard
to describe this type of gap in words, maybe someone else will
give their explanation also. And maybe someone has an image
posted somewhere of this gap design.
In any case, this type of gap is capable of superior quenching
because of its series rotary construction. In a typical rotary, the
spark snakes through only two gaps or four. In the series rotary,
this characteristic of the spark snaking through multiple gaps
within the rotary is taken to the extreme. Because the series
gaps are part of the rotary, no external static gap is required.
Some coilers have stated that these gaps quench too fast for
normal Tesla coils, and that they are suitable only for magnifiers,
but I can assure you that this is not the case, since I have used
these gaps on both normal TCs and on magnifiers with excellent
results. I have also used these series rotaries, and regular
rotaries (not at the same time) on magnifiers with similar results.
But if a regular rotary is used on a magnifier, then a separate
vacuum quenched gap is needed in addition, since magnifiers
are difficult to quench in general. When using series rotaries,
it is essential to use a high enough voltage to be able to jump
across all the multiple series gaps within the rotary gap.
In general no has to worry about their gaps quenching too fast,
its hard enough for a gap to guench fast enough...they never
quench too fast. There may be a misconception about what
quenching really means, and I have written a post in the past
called "two types of quenching". The term overquenching is
often used, but this refers NOT to quenching that is too fast,
but rather to a condition that DOES NOT ALLOW THE GAPS
TO FIRE FREQUENTLY ENOUGH! Thus, it is not really
"overquenching" but rather a "prevention of firing".
The warning not to use rotaries with neon trannies applies only
to non-synchronous rotary gaps. Synchronous rotaries work
excellently with neon sign trannies...probably somewhat better
than traditional static gaps, but I have not yet done a proper,
controlled comparison.
It is of course not necessary to use a series
quenching sync-rotary gap; a regular sync-rotary gap will work
fine at typical neon trannie power levels. I used the series rotary
because I had it handy, but Skip Greiner uses regular sync-rotaries
and obtains excellent results.
Happy and safe coiling to ya!
John Freau