1 Mar
2009
1 Mar
'09
7:53 p.m.
On Sunday 01 March 2009 10:36:33 pm Brent Hilpert wrote:
"Roy J. Tellason" wrote:
That's not necessarily a flaw: 120/240 supplies often do the voltage
selection by switching the circuit between bridge rectifier for 240V and
voltage doubler for 120V. In the bridge config two caps end up in series,
so 250V+250V=500V.
Not if the config is the two caps being across the line, before and after the
typical inductor that's also commonly a part of that filter...
The series connection is usually the two _main_ filter caps, not the line
("mains") filter components.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
If it was
plugged in but not switched on and something popped, it'll be
the mains filter cap. They *do* fail, and they're easy to replace.
In seeing photos of this in the process of dealing with it offlist, it
looks exactly like that's what it was. When I asked about the markings
on the failed parts I was told that they included "250V", which is way
inadequate for UK mains voltages...