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Re: ASRSG question

Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx>


Yes, this is kind of a "brain twister" ;^) Another thing that I just
now thought of is that your were using 30 kV with your 4 station-
ary electrodes while I was only using 14.4 kV. But you mention
that even with your high primary voltage yours still fired more
erractically than with 2 atationary electrodes, even though your
2 stationary electrodes were also 180 degrees apart, but elec-
trically connected by a copper ring band. Srange phenomena
indeed. I wondered if the capacitor discharges somehow ended
up "out of phase" when directed through the 3rd and 4th station-
ary electrodes? A real mystery considering that we're talking
about asynch operation anyway....


----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Friday, April 01, 2005 8:31 PM
Subject: Re: ASRSG question

Original poster: BunnyKiller <bunikllr@xxxxxxx>

Hey David...

interesting "problem"... as you know Im running 2 14.4KV 10 KVA piggies in series for 30+KVAC, my rotory gap is an 1750 rpm motor with milled flats to run approximately 1800 rpm... my rotor disc is set up with a copper band around the periphery of the disc and the disc electrodes are in contact with the copper band. I use only 2 stationary electrodes ( I had it set up with 4 but the 2 in the rear of the disc wanted to arc to the motor, which eventually killed it and required a motor replacement). The rear electrodes were approximately 2" from the motor case, I "thought that was enuf clearance"... just a thought but I wonder if the magnetic field in the motor can direct arcs to it quicker than to the ring/rotor electrodes?? Even tho there is about 1" between the stationary electrode and the copper band ,there is still a considerable amount of arcing from the stationary to the band after the rotor electrodes pass the stationary... BUT I do have to say that the present configuration is alot smoother than the original 4 stationary method, ,the original 4 stationary was erratic and "hard to start firing" ... reading your post got me thinking as to why the older 4 stationary was such a dogged performer... you would think that if it can jump 1.5"+ on 2 gaps it could jump .1" at 4 gaps( .4" total) ...
weird.. no answer on that one... the only thing I can think of is that with the 4 stationary unit the arc direction was "away" from the motor - to the "inside" rotory electrode - to the outer set of stationary - thru the cross over bar - back to the second rotory electrode( 180 degrees apart) - to the "fourth" stationary ( near the motor case) and off to the primary... the 2 stationary set up is from stationary 1 towards the motor to the rotory electrode thru the copper band to the second rotory electrode and out away from the motor to the second stationary electrode....

okay that sed... with the 4 stationary arc flow was away from the motor and the with the new 2 stationary towards the motor.... with the 4 stationary I had arcs to the motor ( opposite of the desired arc flow) the 2 stationary is towards the motor as far as arc flow is concerned.... hope this makes sence cuz I just reread it and now Im all messed up... :)

Scot D

Tesla list wrote:

Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx>

Hi all,

I have noticed a problem with the ASRSGs that I have built. I think
I may have already mentioned this a few years ago and IRC, it was
sort of a mystery then. The problem is that when I make a rotary
gap of the dual gap style (2 pairs of stationary electrodes placed
180 degrees apart along the periphery of the rotary disc so that
each time that it fires, the discharge goes through 2 rotary elec-
trodes instead of 1). Is that clear as mud? Anyway, when I try to
run my ASRSGs like that, it will not fire no matter how close the
rotary electrodes pass to the stationary electrodes or if it does
fire, it fires very erratically and ends up smoking something in
the control panel (I blew out a 1000 volt, 50 amp FWB rectifier
brick for the DC motor of my RSG last time)! In the past I was
able to rectify this issue by either going with a single rotary gap
or if I kept it double series, I had to use a motor with a double shaft
and keep both sets of stationary electrodes on the same side of the
motor. Does this make any sense? Also, I've noticed that SYNCHED
rotary gaps don't seem to have this problem with running double
rotary gaps 180 degrees apart. Can anyone tell what gives with this?
The only reason that I was thinking of using a double-seriesed ro-
tary gap is that I will be pushing up to 15 kVA with my latest
Tesla system and that will produce considerable heat at a single
contact point.

Also, I've changed secondary coil from a 12.5" x 44" long wound w/
900 turns of #17 magnet wire to a 12.75" x 48.5" long wound with
1260 turns of GREEN # 19 magnet wire. I think that #19 is still
large enough wire for this and I know the 1260 turns is a better
number of turns than 900, keeping in the 1000 to 1500 turn range.
That  will be a better choice for secondary coil for a 15 kVA coil with
a 12x56 toroid. I have a 0.2 uFD primary capacitor  and a 15 kVA,
14,400 volt PDT to power it. Actually, I have (2) 15 kVA PDTs so
so I could series the PDT outputs for nearly 30 kV!.Of course, I
would then have to series instead of parallel my (2) Hipotroncs 0.1
uFd, 50 kV pulse caps for a 0.05 uFD, 100 kV assembly instead of the
0.2 uFd, 50 kV configuration that I now have. My rotary electrodes are
(8) each 1/2" x 2 1/2" long tungsten carbide drillling blanks and my
stationary electrodes are (2) each 1/2" x 3" long tungsten carbide
drilling blanks mounted in 2 1/2" long, 1.25" brass square stock.
Actually it WAS (4) stationary electrodes but now is (2) due to
the problem that i mentioned above in the first paragraph :^) Any
comments are welcome.

David Rieben