Commodore 64 Power Supply
sethm at loomcom.com
Wed Jul 2 01:32:06 CDT 2008
On Mon, Jun 30, 2008 at 1:48 PM, Philip Belben <philip at axeside.co.uk> wrote:
> Roy J. Tellason wrote:
>> The 9VAC has to be a separate transformer winding from the one that
>> provides the +5VDC eventually, because of how it's used...
> There are plenty of transformers around with two 9V secondaries. I'd reckon
> on using on of at least 20VA rating even if you have a switching regulator.
Oddly enough, whereas two 9V secondary windings seem common in the UK,
I'm having a VERY difficult time finding one in the US. I suppose
it's got something to do with the fact that UK/European transformers
are stepping down from 230V mains, where the North American ones are
stepping down from 110-120V mains.
I have been able to find transformers with a 115 V primary winding and
two 18 V secondary windings with center taps. I assume I can use the
center taps, but honestly I'm not sure. Time to consult some higher
authorities! (i.e., Chapter 6 of "The Art of Electronics" and Chapter
17 of "The ARRL Handbook"!)
More information about the cctalk