Commodore 64 Power Supply
Roy J. Tellason
rtellason at verizon.net
Sun Jun 29 19:26:27 CDT 2008
On Sunday 29 June 2008 20:08, Ray Arachelian wrote:
> Seth Morabito wrote:
> > Does anyone know of a commercially available replacement power supply,
> > before I go off and build one? A linear supply would be trivial to
> > design, but I've never done a switching power supply, which I suppose
> > would be greatly preferable. The trick with the C64 is that it
> > requires both 9V AC and +5V DC. (I've considered frankensteining
> > together 9V AC and +5V DC wall-wart adapters onto the same DIN-7
> > cable, but it just feels so very very wrong).
> Sounds like you just need a single 9VAC power supply, a bridge, a
> voltage regulator, and perhaps some caps to clean up the signal a bit.
> The trick is to provide enough wattage.
The 9VAC has to be a separate transformer winding from the one that provides
the +5VDC eventually, because of how it's used...
One thought that came to me after my previous response was posted is that if
one happens to have a really trashed 1541, that transformer could be used,
as well. In fact, I built a bench supply that worked that way, though my
attempts to try and run two 64s off it at the same time never worked, even
though I had separate regulators for the two outputs. Too much interfence
between the two. Any time I'd hook two computers up and turn 'em both on the
output voltage on both would drop way down, and my scope showed me some
seriously bad oscillations going on. I suppose these days I know a bit more
about how to treat those 3-terminal regulators, but I've never bothered to
modify the thing...
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