1 Jul
2008
1 Jul
'08
1:26 p.m.
Brent wrote:
so one may have unpredictable behaviour as to which
diodes take
the current and/or issues with unintended current flow in some supply
paths.
It generally won't matter that much which bridge is providing
the ground return path. It will provide the necessary reference
voltage.
If the lower-rated diode happens to have a slightly lower forward
drop at low current, it will start carrying more current, but that
will make its forward drop rise, and the higher-rated diode will
then start conducting more. (Unless the forward ratings of the
two bridges are significantly different.)
I haven't looked at what the low-current bridge
diodes are rated for,
perhaps it would work for the currents involved, but I think it looks bad
from a 'design principles' perspective.
I won't claim that it's great, but I've seen it done in many pieces
of equipment, and haven't ever actually seen a problem result from
it.
If one were willing to modify the C64 you could open
the ground lead of
the existing bridge (so that you have two half-bridges for the two
positive sides, and one half-bridge for the ground side).
That will cause a worse problem than the one you're trying to solve.
Eric