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Re: More Tuning/Debugging Next

Tesla List wrote:
> 
> > Subject: Re: More Tuning/Debugging Next
> > >Subject: Re: More Tuning/Debugging Next
> 
> >From hullr-at-whitlock-dot-comTue Sep  3 22:18:18 1996
> Date: Tue, 03 Sep 1996 11:15:07 -0700
> From: Richard Hull <hullr-at-whitlock-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: More Tuning/Debugging Next
> 
> Tesla List wrote:
> >
> > >From jim.fosse-at-bdt-dot-comSat Aug 31 10:37:02 1996
> > Date: Sat, 31 Aug 1996 07:40:22 GMT
> > From: Jim Fosse <jim.fosse-at-bdt-dot-com>
> > To: tesla-at-pupman-dot-com
> > Subject: Re: More Tuning/Debugging Next
> >
> > >From: Esondrmn-at-aol-dot-com
> > >To: tesla-at-pupman-dot-com
> > >Subject: Re: More Tuning/Debugging Next
> > >Big Snip
> > >
> > Ed,
> >         Do be careful running without resistive ballast. I've taken
> > out 2 microprocessor controlled lamp switches in my house during my
> > ballast testing. Both were small off the line powered time or movement
> > switches and both probably went when I was testing inductive only
> > ballast. (not sure at what stage of test the went, but my TC didn't
> > take them out and they were dead after my ballast test without the TC
> > connected) I think that the cause was running the inductive ballast
> > without a dampening resistor to lessen the flyback into the mains that
> > caused their failure. At 60Hz, the 2 RFI filters in series were of no
> > use. I have seen hot 1/8"? arcs from my ballast inductor to my RFI
> > filter case (earth ground) when I "misplaced" the inductor next to the
> > filter.
> >
> > During testing, I had to place a 23uF motor start cap from
> > line-to-line after my RFI filters and before the ballast to prevent
> > the RFI filters from shorting. It was a 3 phase filter, 2 phases are
> > now shorted together.
> >
> > If I remember correctly, you were using multiple oven elements for
> > resistive ballast? try using fewer elements. This will reduce the
> > dampening of your arc welders inductance.
> >
> >         jim
> 
> All,
> 
> Here, here, I second the motion.  We have struggled here in Richmond to
> learn all this the hard way too.  On tape #8 1990 we finalize this maxim
> for all to see.  The resistance is a must for all the above reasons with
> pole type xfrmers.  Bill Richards ignited a lamp socket in his ceiling.
> He also burned out a wall light switch.  Alex Tajnsek took out a stove
> exhaust fan (caught fire).  The bunggy cord nature of the resitive
> portion of the ballast mushes the response of the big inductor.  Gotta
> have it for best operation!  I believe it was in 1990 that I wrote a
> sysergistic tune paper for Harry Goldman.  This covered spark gaps, etc.
> 
> Richard Hull, TCBOR

Jim,

I was just reading a section on distribution transformers in a book
called "Electrical Power Technology" by Theodore Wilde (John Wiley &
Sons, 1981). The discussion on the no-load saturation curve for these
transformers says that transformers are usually designed to operate at a
peak flux density of about 1.5 Tesla, which roughly corresponds to the
knee of the saturation curve. This implies that, even with no load, the
primary current will rise dramatically once we begin to apply any
significant overvoltage to the winding. "We can exceed the nominal
voltage by perhaps 20%, but if we apply twice the nominal voltage, the
exciting current may exceed the nominal full load current, even when the
transformer is not loaded". This sounds exactly like the situation a
number of coilers are using:  overdriving the 120 volt winding(s) to
push a 6-7.2 KV pig to a higher output (12-15 KV). 

Have any coilers actually measured the pig's primary current draw with
NO output loading versus input voltage??  If the pig is heavily
saturating, will this tend to improve or worsen the transients created
by the inductive ballast when the gap extinguishes?? 


-- Bert --