Re: PFC current load

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Jonathan,

If you place a cap directly across the AC line, like for a PFC cap, the current
is:

I = Vac x (2 x pi x F x C)

I is the RMS current
Vac is the RMS line voltage
pi = 3.14159...
F = 50 or 60 Hz.  AC line frequency
C is the capacitance in "Farads"

So a 100uF cap is:

 I = 120 x (2 x 3.14159 x 60 x 100e-6) = 4.52 Amps RMS

It is proportional so a 50uF cap is 2.26 amps and a 200uF cap is 9.04 amps.

Cheers,

        Terry


At 08:27 AM 11/18/2001 -0800, you wrote: 
>
> Hi All,
>  
> Finishing up the PSU controller for my new coil. I want to be able to turn
> the PFC caps on and off during operation, and since I will run two different
> coils with two different NST on this PSU, I want to be able to change the
> value of the PFC caps. So my question is this: How much current runs through
> the PFC caps?  The switches I have are all around 3-5 amps, so should I run
> it through a relay?
>  
> Thanks all,
>  
> Jonarthan Peakall