Re: 6 MOT Coil

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

Original poster: "Allanh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <allanh-at-starband-dot-net>

Thanks for all the info. I have not had great luck with MOT's, they
certainly have loads of power, but are difficult to manage. NST's are very
tame and easy to use, but then we all start dreaming of more power and 7
foot streamers. I've found that in my experience, each time I take a leap
forward in power, my results are dissappinting at first then after much work
I surpass the previous mark, but so far the MOT's haven't outdone a pair of
big NST's.
I'm still trying to find a good and cheap way to ballast these beasts, and
thats the right name for them. I may need a larger Pri/sec. Currently my
specs are 4" sec, 24" long, 900 turns #23, Sec. 1/4" cp. 13 turns 1/4"
space.
I have two sets of caps made up of 10 each .33 mf -at- 2000 VDC. So I can have
up to 66 nf -at-20KV. My spark gap is an SRSG 1800 RPM with 4 electodes and two
fixed for 240 BPS. They get HOT after a few minutes.

Good luck,

allan

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, September 05, 2002 11:00 AM
Subject: Re: 6 MOT Coil


>
> Original poster: "tesla by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<tesla-at-paradise-dot-net.nz>
>
> Hi Allan
> Not too sure if your question is for Tim or myself but I can advise re my
> coil.
>
> I'm sure I'm actually quite a long way from optimised yet. It makes an
> impressive display but for the power I'm running I don't think I'm
> efficient.
> I've tried a few configurations and I'm on the track to improve it still.
> I'm currently using an 8" dia sec with 54" of 0.56mm wire with 6"x27"
> toroid. This sec loaded is about 57kHz and interpreting recent postings re
> the OLTC I suspect the Q of my sec may be a little low. My re try a 12"dia
> space wound 54" with 19tpi
>
> The big deal with MOT's I've decided is lots of Cp ie at least 120nF and
> lots of bps ie at least 300 and probably more. Keeping lower bps with my
> 88nF MMC does offer the advantage of limiting the mains current while I
> play. Recent runs with 6MOT's have a total I/P of about 25A at 230V. (I
need
> to check that figure but its no far off)
>
> My coil is totally conventional in every way. A standard AC drive to a
> primary of 1/4 refrigeration tube wound on 1/2" pitch with a simple SRSG
or
> a TCBOR static. I'd note that the TCBOR gap set wide still gives the
loudest
> biggest sparks compared with any SRSG configuration I've tried (due much
> higher bps) but it suffers from surging current draw from the mains (and
> lots more of it I might add). I inevitably drop a breaker when using the
> static gap but before I do the beast is alway going very well at about 7'.
> Despite this the smoothness and control of the SRSG is still my preference
> and I'm going to optimise this element. A high bps ASRG also is worth a
> thought (see Tims coil)
>
> Some points which may be useful.
> 1) I've made great use of rigid foamed PVC (plaswood) in my construction.
A
> really wonderful plastic material which I think is under recognised by
> coilers particularly as a primary support system. The pri sits on a 20mm
> sheet and the 15deg supports are made from 10mm. This stuff has ideal
> properties,its particularly light, strong, gluable, and easy to machine or
> cut. And yes its really cheap as it's mostly air.
> 2) Modest inductive ballasting and PFC have been worthwhile for me.
> 3) MOT's have worked really well for me no insulation or heating issues to
> date
> Good lick and care
> Rgds
> Ted L in NZ
>
> > Original poster: " <allanh-at-starband-dot-net>
> >
> > I'd like to know the specs of your coil, sounds like you have found a
> sweet
> > spot.
> > allan
> >
>
>
>
>