Re: mot's

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

Original poster: "Gregory Hunter by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ghunter31014-at-yahoo-dot-com>

Hi Jason,

Straw man argument. High-precision, high-speed, low
firing voltage asynchronous rotary spark gaps are the
exception, not the norm. For 99% of hobby-level
coilers, a 15A breaker is inadequate for two
unballasted MOTs. I saw a guy at the 1st UK teslathon
running a 10,000RPM ARSG with an unballasted (!) 5KVA
pole pig, but that doesn't mean it's a common setup or
even a very good idea.

I'm pleased to hear your ARSG works so well. I'm
inspired to contemplate building a copy, since I work
with MOTs quite a bit. I've got a nice chunk of .125"
Aluminum sheet stock in my junk box. I don't know the
exact alloy, but it is hard, flat, and mirror smooth.
I bet it would make an excellent rotor for an ARSG
along the lines of yours. Now I just need a motor with
near-zero play in the bearings. Do you have a link
where I can have a look at yours?

Best Regards,

Greg
http://hot-streamer-dot-com/greg

--- Tesla list <tesla-at-pupman-dot-com> wrote:
> Original poster: "Jason Johnson by way of Terry
> Fritz <twftesla-at-qwest-dot-net>"
> <hvjjohnson13-at-hotmail-dot-com>
> 
> 
> > A 15A breaker is inadequate for two MOTs unless
> you
> > use additional ballast. I used a 240V 20A window
> A/C
> > outlet, and the MOT twins pulled right at 20A all
> the
> > time.
> >
> > Regards,
> >
> > Greg
> > http://hot-streamer-dot-com/greg
> 
> A fifteen amp breaker isn't necessarily inadequate
> even without ballasting.
> I use a 460 BPS arsg with my two unballasted MOTs
> (no voltage doublers, no
> protection filter, not even a safety gap) on my coil
> that throws 5-6 foot
> sparks (when its dry I see regular hits past 6 feet,
> longest to date is 78")
> and it runs on a 120 volt 15 amp breaker and can run
> several minutes at full
> power without any problems. With any static gap
> short of a monstrous
> airblast gap or good triggered gap, you will
> regularly trip a 15A breaker, I
> suggest a rotary gap. If you have no voltage doubler
> like me, you will spend
> a whole day getting the tolerances close enough to
> fire at such a low
> voltage (mine fires reliably at 1800 volts, but it
> took me two days to get
> it that good, all I've got for machining is a cheap
> drill press).
> 
> By the way, for those of you who said my rotary gap
> was going to fail in
> short order because of the Al rotor directly on the
> motor shaft, the coils
> cumulative run time with the gap is getting up into
> several HOURS, and I
> have yet to see a single problem. The bearings that
> you said should have
> spot welded themselves together are as good as the
> day I bought the motor, I
> can spin the rotor by lightly blowing on it, and
> there isn't a single noise
> or vibration from them :-)
> 
> << Jason R. Johnson >>
> G-3 #1129
> The Geek Group
> http://www.thegeekgroup-dot-org/
> 
> 
> 


__________________________________________________
Do You Yahoo!?
Make international calls for as low as $.04/minute with Yahoo! Messenger
http://phonecard.yahoo-dot-com/