"John Fields" wrote in message
...
On Sun, 5 Mar 2006 22:49:35 -0600, "DB" wrote:

Unfortunately I don't have a schematic. There is only one capacitor, but
it
has three terminals. That and the notation on the side makes me think it
may be some kind of a dual capacitor in one big can. I had never heard of
such a thing before, but could that be what it is?


More than likely, that's precisely what it is. Back in the stony
ages it was quite common to have two or three electrolytics in the
same can. The way you describe yours though, makes it sound like
there's a separate terminal coming out of the base for the common
connection, when usually a tab which was part of the case was used
for the common connection. Is thare any other marking on the case?
Like "TYPE FP" or anything like that?

I picked up a couple of 5000 MFD 25VDC capacitors for $1 each, hoping that
they might be suitable replacements. The new capacitors are marked "Type
PFP." The old 5000 MFD 20VDC dual capacitor didn't have any markings to
indicate the type. The old capacitor case looks like it is made of
bakelite, by the way.

The new capacitors have three terminals that are part of the aluminum case,
and a fourth terminal slightly off-center from the base. The fourth
terminal has a little square marking next to it. There does not appear to
be any measureable resistance between any of the terminals, including the
central one.

I am wondering how I can determine if these capacitors are suitable
replacements. I'm also not sure how to figure out which terminal should be
connected to the positive output of the power supply, and which to the
negative. Any assistance would be greatly appreciated.

- D. Boucher