Re: The never ending saga: Ballasting

• To: tesla-at-pupman-dot-com
• Subject: Re: The never ending saga: Ballasting
• From: "Malcolm Watts" <malcolm.watts-at-wnp.ac.nz> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
• Date: Fri, 03 Mar 2000 10:45:28 -0700
• Approved: twftesla-at-uswest-dot-net
• Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Hi David,

> Original Poster: "David Trimmell" <davidt-at-pond-dot-net> 
> 
> Hello,
> 
> A few days ago I posted questions regarding ballasting and was wondering
> why the voltage drop. Tonight I have done some experiments, as empirical
> data is needed for someone who barely understands this (ME!). I tried a
> inductor in series with my PT, a 60 mA neon primary with secondaries
> shorted together. I got almost a 40 volt drop to the PT, I was only getting
> 100 V into it (0-140 volt variac). Then I tried 16 uF Cap across the mains
> right after the inductor (neon primary), and heck if I was getting 135
> volts, only dropping 5 volts from the variac supply! Now have I truly
> missed the boat? Probably. But why didn't someone just mention that I
> needed to place some C across the lines to get back lost voltage? I tried
> it again with another inductor and found I could limit current to 15 amps
> at 135 volts, with terminals shorted on the PT, and this followed my
> calculations including DC resistive losses (as measured). Voltage drop from
> impedance is something I don't quite follow. But it does seem that a little
> capacitance in the inductive current limiting scheme is called for. I found
> no indications of mains resonance, but can anyone explain how/why?

Seems to me that some power factor correcting is going on. 
Effectively you have a parallel resonant circuit in series with the  
NST inductor so some of the inductance in the circuit is being 
cancelled. Does this make any sense?

Regards,
Malcolm

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