On 2015-08-18, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
Tom Gardner fired this volley in news:mqufgp$qs1$2
@speranza.aioe.org:

Can one use two discrete caps?


Indeed. "Dual caps" are just a packaging convenience. They're
fundamentally a service problem, because if half fails, you must replace
both.

And, depending on the failure mode, it can make diagnosis a bit
more complex. Mine, when it failed, had the connection of the common of
the two caps to the common output terminal open, so in effect there was a
smaller value cap between the two load points. That was enough to start
the fan (with the compressor acting as a virtual ground), but far too
small to start the compressor, so it kept cycling, with the current
limit opening and then re-closing a few minutes later, resulting in a
repeated dimming of lights. And, when it tried to check it, it appeared
that the cap was good. :-)

Most discrete-component television sets of the late 60s and early 70s that
ended up on a service bench could be seen to have had at least one dual cap
replaced with single-capacitor equivalents.

Those would be the electrolytic caps, no doubt. (Mostly power
filter after rectifiers.) They had the common ground in the metal case,
and could benefit from the lowered cost of manufacture -- and the
lowered cost of mounting components.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---