21 Apr
2006
21 Apr
'06
6:19 p.m.
Th remaining fault is within the soldered up filter /
overload trip /
voltage selector unit, which has an open circuit live line. It seems to be
special to the Decserver (I had a spare from a scrap DELNI, but it is
subtley different), so I'll have to wait for another to show up.
I've been known to use a _BIG_ soldering iron to get those cans apart (I
took apart the filter cans in a Modem 2B...).
Anyway, home many connections from this unit to the rest of the PSU? Most
of the time, there's mains input (2 wires, live and neutral) and another
pair to the voltage selector which are connected for 115V and open for
230V (this converts the input bridge rectifier to a voltage doubler for
the lower mains voltage, I am sure you know the circuit).
The mains input IEC plug goes throught a traditional LC filter -- the
normal circuit is a capacitor between L and N on the input side, then a
bifilar-wound choke, then three delta-connected capacitors between L, N
and E. The live side -- after the filter, normally -- is fused. Then the
output of that goes to the PSU.
Unless there's something serieously unconventional going on, it should be
possible to make up a replacement.
-tony