# RE: Looking for run caps, urgent

```Original poster: "Ted Rosenberg by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Ted.Rosenberg-at-radioshack-dot-com>

Mike: Thanks a bunch for the extraction!
I'm at the office so I can't quote the original formula I used but it was
from the pupman archives doing a search on PFC.

Obviously 72µF is a major difference than 165µF for a 15/60.

Maybe the best way is to install 72µF and clamp an amp meter on the line
All of this will happen after the run at Hangman's. I visit my coil on
weekends <smile>

Safety First

Ted

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Monday, October 22, 2001 6:03 PM
To: tesla-at-pupman-dot-com
Subject: Re: Looking for run caps, urgent

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

There is indeed something amiss.  I extracted this from John Couture's site:

The following can be used to correct any LPF NST to about 90% power factor.
C = K1*V*A
C = PFC capacitor in microfarads(UF)V = NST secondary volts
A = NST secondary amperes
K1 = .08 for 120 volts at 60 HZ
K1 = .02 for 240 volts at 60 HZ
Example NST 15000 volts 60 milliamps(ma) 60 Hz
For 120 volts  C = .08*15000*.06 = 72 uf
For 240 volts  C = .02*15000*.06 = 18 uf
Do not use larger capacities because this could result in leading power
factors
which are undesirerable.

I think there is some serious discrepency for the PFC calculation.
Mike

>
> Jonathan:
> There seems to be some weirdness here.
>
> Terry...you might want to jump in.
> I ran the formula using my 15/60 as a model. The answer was 165µF.
> But in an earlier e-note you suggested that only 100µF would be enoug

```