Re: MOT-powered coil questions

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

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

OK Dwight,

I stand corrected. Apparently, the lower limit for
spark gap tesla coil supply voltage has yet to be
established. Perhaps someday under the guidance of
this sage group, you can dispense with the transformer
altogether, and fire a coil directly from 120vac wall
current. However, I'm going to go out on a limb here
and assume that you are not interested in micro- or
flea-power coiling for your first effort, nor are you
interested in sub-kilovolt spark gap research. If I
correctly understood your initial query to the list, I
believe you are interested in building a practical,
MOT-based Tesla coil, and that you are seeking useful
advice to that end. If this is so, then based on my
limited experience, I suggest that 4kvac from a pair
of MOTs is a tough way for a novice to start out.
Quenching a low voltage/high current arc presents
difficult design challenges that most newbies would do
better to avoid. Raising the voltage a bit with a
level shifter, or by simply using 4 MOTs instead of 2,
sidesteps many problems and greatly simplifies spark
gap design. If you'd like to hear more of my
half-baked ideas on MOT power supply design for tesla
coiling, please refer to my various primers on the
subject.

http://hot-streamer-dot-com/greg/MOT_chat.htm
http://hot-streamer-dot-com/greg/MOTDOC.htm
http://hot-streamer-dot-com/greg/4pack.htm

Best Regards,

--- Tesla list <tesla-at-pupman-dot-com> wrote:
 > Original poster: "Edward Wingate by way of Terry
 > Fritz <teslalist-at-qwest-dot-net>"
 > <ewing7-at-rochester.rr-dot-com>
 >
 > Tesla list wrote:
 >
 >  > Original poster: "by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>"
 > <dhmccauley-at-spacecatlighting-dot-com>
 >  >
 >  > I disagree whole heartedly.  Even 3kVAC is enough
 > for a reliable spark-gap
 >  > driven tesla coil.  Plus many of us, Ed Wingate,
 > Steve Ward, Gary Lau, and
 >  > others have built
 >  > very successful tesla coils utilizing only 4kVAC
 > transformers.  Theres more
 >  > than enough margin for reliable operation.
 >  >
 >  > The Captain
 >  >
 >  >  Dan,
 >
 > After my "test" minicoil was completed and while
 > waiting for my France
 > 4020SE transformer to arrive
 > I got 3" sparks using a 2KV/20MA transformer pulled
 > out of a HiPot tester
 > firing through 2 gaps of
 > my 21 gap fixed gap assembly. The operation of the
 > coil was stable even
 > with the flea power.
 >
 > Ed Wingate RATCB
 >
 >



=====
Gregory R. Hunter

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

_