Re: MOT Coil operational notes

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

Original poster: "tesla by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla-at-paradise-dot-net.nz>

Greetings Finn et al
Many thanks for your input Finn
I'm rushed today but wil look closely at your timings and perhaps contact
you off list to clarify some points.
Yes you do have the correct notion
Firing at top dead centre and then 15deg eithr side.

Agree this is very close.
This was arrived at after measuing the O/P current spike of >2A that the MOT
could deliver.

Agree things are chaotic with this system as those ring up voltages would
suggest.

What I did not understand at first reading re firing times was are these WRT
the zero crossing time and was it a 50 or 60Hz system

Best
Ted L

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, December 01, 2002 4:07 PM
Subject: Re: MOT Coil operational notes


 > Original poster: "Finn Hammer by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<f-h-at-c.dk>
 >
 > Ted,
 >
 > Having done some work on both MOT supplies and 300 BPS systems I dare
 > say:
 >
 > 1) There is nothing about a mot that makes it special in terms of
 > magnetics.
 >
 > 2) You cannot set the electrodes of a 300 BPS SRSG without either a
 > simulation package, and a scoped primary circuit for fine tuning. Things
 > get really hysterical with these systems, and their behaviour beats
 > intuition. At least mine :o)
 >
 > Am I reading you right, that you have an electrode at -15 deg, top, and
 > +15 degrees of the incoming voltage waveform? 15 degrees sound awfully
 > close to me.....0.83 mS
 >
 > Perhaps you will find it interesting to see the timing that I used on
 > the Museum coil.
 >
 > In that setup, the firing af the gaps happens at 2.4mS  6.45mS and
 > 8.85mS
 >
 > http://home5.inet.tele.dk/f-hammer/tesla/museum/setup/setup.htm
 >
 > I ran a sim of your primary, and came up with these firing points:
 >
 > 0.2mS  5mS and 7.4mS,
 >
 > Richie has got some info along these lines:
 >
 > http://www.richieburnett.co.uk/external.html
 >
 > but it is getting late so I:
 >
 > hope this helps, Finn Hammer
 >
 >
 > Tesla list skriver:
 >  >
 >  > Original poster: "tesla by way of Terry Fritz <twftesla-at-qwest-dot-net>"
 > <tesla-at-paradise-dot-net.nz>
 >  >
 >  > Team
 >  > A few observations re 6MOT coil FYI and possible comment re excess Vp
 >  >
 >  > 88nF/57kHz/6MOT's/Primary ballasting 22mH/6 to 8kVA/300mm x 1200mm
toroid/
 >  >
 >  > 1) ASRG (up to 3000bps) works but not as well as SRSG  (in terms of
spark
 >  > intensity and length)
 >  > 2) Safety gap fires furiously with gap at 12mm with SRSG banging at
300bps
 >  > (Vpk+/- 15deg)
 >  > 3) 300bps SRSG seems to excite resonance due Cp 88nF and source
inductance
 >  > of MOT psu. Where else is the excess Vp coming from ?? (see 2 above)
 >  > 4) Even with stress of Vp jumping 12mm (6mm per side) MOT's hold
up.(oil
 >  > baths used)
 >  > 5) High bps on ASRG drives streamers near vertical. Ground capacitance
 >  > shunts field at high bps ??
 >  >
 >  > Best
 >  > Ted L in NZ
 >
 >
 >