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Re: Power Factor Correction weirdness?

Tesla List wrote:
> 
> Original Poster: Adam <adamsmith@mediaone.net>
> 
> Can someone explain what I'm seeing when I attempt to power factor correct
> my neons? I've got my DMM in series with the primary of a 12,000 60mA NST,
> and the secondary of the NST is shorted.  With no PFC caps, it reads 7.13
> Amps.  But when I start adding caps in parallel with the NST primary, the
> current reading drops dramatically-- more than I expected it to.  Here are
> the results:
> 
>     PFC Caps    Ammeter Reading (amps)
> 
>     0                7.13
>     50 uF            4.96
>     100 uF           2.81
>     150 uF           1.14
> 
> What's going on here? is this right?
> 
> -Adam
> adamsmith@mediaone.net

	Sounds about right!  My simple calculation says the optimum capacitance
should be a bit over 100 ufd.  Remember, under short-circuit conditions
you're drawing almost no power and the primary current is due to the
transformed inductive leakage reactance; the purpose of the PFC is to
supply that current, instead of it coming from the power line.

Ed