[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: PFC Question

Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi David,

No. The ballast needs to be "down stream" from the PFC caps. You need to form a parallel LC circuit so the leading current in the PFC caps cancels the lagging current in the ballast. If you put the PFC caps across the pig with the ballast upstream, you will form a series LC circuit that at resonse will form a low impedance and increase the current draw. Parallel LC circuits at resonance form a high reactive impedance to the variac output so the only draw will be the "real" current. Put the PFC directly on the variac output and have this output feed the ballast in series with the pig.

Gerry R.

Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx>

the variac. So if I were so inclined to reinstall the PFCs, they would need to go DIRECTLY across and in parallel
with the 240 volt input lugs of the pig, right? That should
remove the seriesed ballast L from the picture. I may try
temporarily connecting the caps directly across the input
lugs of the pole pig and see if that makes any difference.

David Rieben


----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Thursday, November 03, 2005 9:40 AM
Subject: Re: PFC Question


Original poster: "Gerry Reynolds" <gerryreynolds@xxxxxxxxxxxxx>
Hi David,
Where is your ballast if the output of the variac is connected directly to the input of your PIG.
Gerry R.

Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx>

Hi Ed,

I must not have explained myself properly.
My PFC caps were directly across the out-
put terminals of the variac and consequently
across the input terminals to the transformer.
That's in parallel with the input terminnals of
the transformer, isn't it? And the variac would
start the resonant saturation hum even with the trans-
former disconnected from it, or with no load.
I even tried removing one of the 100 uFd
caps to make it 600 uFd PFC but that didn't
really seem to help so at that point, I just decided
remove them altogether.

David Rieben