Date: 2004-01-12 13:35:05
I actually knew that the transformer in the original C-64 PSU has a transformer with two windings, but I am not sure that's really necessary. I think a single winding would be adequate, given enough VA of the transformer. If that's not the case, I'd like to hear why. In any case, it's really trivial to use two windings instead of one, in the design I presented. It doesn't increase complexity at all. When I get home I'll prepare another schematic, to work with commodore's original transformer. cheers! mario -----Original Message----- From: firstname.lastname@example.org [mailto:email@example.com]On Behalf Of ext Hársfalvi Levente Sent: 12. January 2004 11:50 To: firstname.lastname@example.org Subject: Re: C64 power supply replacement Hi!, Gianmario.Scotti@nokia.com wrote: > A transformer doesn't have separate taps for 9 V AC *AND* regulated 5 V :o) > And I did put a fuse in the 9 V AC line in the schematic. The transformer in the C64 PSU has two independent secondary circuits, 9V AC each. One of these circuits is rectified and regulated (5V DC), the other is just brought to the C64 (only a fuse is used). See these schematics: http://www.funet.fi/pub/cbm/schematics/computers/c64/c64-powersupply.gif http://www.funet.fi/pub/cbm/schematics/computers/c64/c64extps.gif As you see, the two outputs (5V dc, 9V ac) are fully "independent" in the original PSU design. They aren't grounded together in the PSU. Regards, L. Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing list
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