Re: Primary inductance vs. coupling

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 12/4/01 2:54:34 PM Eastern Standard Time, tesla-at-pupman-dot-com
writes:

Jason,  

The value of the main cap does affect the power factor in an NST
system.  LTR operation tends to make the power factor worse, so
it becomes more important to use a PFC cap.  You are correct
that this is all affected by the breakrate.  I would think the cap
would discharge most of it's energy though when the gap fires.
Richie Burnett has a good explanation of all these issues at his
website.  I played around with some of these issues using a PT,
and a variable ballast some time ago.  Some ballast adjustments 
give a really bad power factor.  The real power as measured with
a wattmeter will be fine, but the apparent power is miserable. 
There's also a lot about this in the archives from a couple years 
ago.

Cheers,
John


>
> By the way, I noticed that when running very LTR (35nF) as opposed to 1.5x
> resonant (25nF) the current draw on the mains is larger by about 500mA,
> which is to be expected. This change does not happen when PFC is added to
> the low voltage side of the neon... I wonder if the primary cap on the high
> side is acting as a PFC cap too? This would indicate that the cap is not
> fully discharged (by any means) after the gap has fired. The breakrate also
> seems to have an effect on this - 200 breaks lowers the effect. Any clues to
> what is happening?
>
> Best R,
> Jason
>
>