1 Jul
2008
1 Jul
'08
7:23 p.m.
OK, I stand corrected. I finally got home tonight,
and was smug enough
to go out and pull the units.
First, the lightweight PSU I have with a C128 is not a C128 PSU at all,
but a A500 PSU. I am sure we tested the PSU with a C128 last week (we
were going through the units prior to the C4 CBM EXPO this past
weekend), but I'll have to check. The reason's it is so light is it
only provides DC on the outputs. 5 and +-12. It simply chops mains to
get what it needs, I would guess.
The A500 PSU is, indeed, a conventional switcher. Rectifies the mains,
chops it, feeds it into a transformer, rectifies the output, and has
control feedback fro mthe 5V output to the chopper controller for
regulation. The 12V outputs just 'tag along'.
I thought it was very foolish of Commodore to have 2 PSUs with different
outputs that used the same custom connector (a thing that looks like a
square DIN plug). IIRC plugging the Amiga PSU into a C64 does no daamge
(I can't remember if the machine basically works or not), pluggling the
C64 PSU into an Amiga can do damage (applying 9V AC to DC rails).
The other C128 PSUs are heavy as a common brick, and Roy looks to be
right. They have what looks like a switcher under the huge transformer.
That's what my C128 PSU has.
-tony