Gianmario.Scotti_at_nokia.com
Date: 2004-01-10 17:19:13
In case you can't read ACCEL schematics, here's the same thing in .PNG
> -----Original Message-----
> From: owner-cbm-hackers@cling.gu.se
> [mailto:owner-cbm-hackers@cling.gu.se]On Behalf Of ext
> Sent: 10 January, 2004 17:52
> To: cbm-hackers@cling.gu.se
> Subject: RE: C64 power supply replacement
>
>
> Wow, that looks like a brick of epoxy! Umm... so it's not the
> "guitar pedal"-type C-64 PSU.
>
> What I meant by reverse-engineering, is: what "signals" it
> gives on the "output" and make a circuit that does the same.
> You don't need to know how it's made. If I understand
> correctly, it gives 9V AC and 5V DC regulated, right? First
> question that pops to mind: why didn't CBM simply make a PSU
> that contains a transformer and nothing more, which would
> give 9V AC, and then the rectification and regulation (to
> obtain 5V DC) would be done inside the C-64 ? Just look at
> how the C-16/C-116 is done. (actualy, there the PSU contains
> a transformer AND a diode bridge+electrolite capacitor, to
> rectify (but not regulate, yet) the AC to DC).
>
> Anyway, supposing a temporary engineering brainbarf on part
> of CBM, the PSU to make would be fairly simple, really. Check
> the ACCEL Schematic I attached here.
>
> > -----Original Message-----
> > From: owner-cbm-hackers@cling.gu.se
> > [mailto:owner-cbm-hackers@cling.gu.se]On Behalf Of ext Ryan
> Underwood
> > Sent: 10 January, 2004 14:26
> > To: cbm-hackers@cling.gu.se
> > Subject: Re: C64 power supply replacement
> >
> >
> > On Sat, Jan 10, 2004 at 03:33:13AM +0200,
> > Gianmario.Scotti@nokia.com wrote:
> > > Hey Ryan,
> > >
> > >
> > > sorry to hear about your problems with the PSU.
> > > However, could you tell me more about this "Pinto" power supply?
> > > How does it blow up your C-64, exactly?
> >
> > I read on comp.sys.cbm archives that this power supply used a
> > rectifier
> > to cut the 9V down to 5V, and eventually due to heat/age, the
> > regulator would short and you would end up with 9V on the 5V output,
> > which isn't too nice to the C64 logic...
> >
> > > And, do you have pictures of this PSU, so I can be sure
> > which exactly you mean?
> >
> > Yeah, see here:
> > http://home.icequake.net/~nemesis/misc/c64-psu1.jpg
> > http://home.icequake.net/~nemesis/misc/c64-psu2.jpg
> >
> > This is after cracking the shell off and trying to chip some of the
> > epoxy off -- you can see a heat/ground plate exposed on the
> right side
> > of the picture.
> >
> > > I think it's simple to reverse engineer the PSU.
> >
> > I would think so too, if I had a way of getting rid of this brick of
> > epoxy without destroying the circuit....
> >
> > --
> > Ryan Underwood, <nemesis@icequake.net>
> >
>
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