The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: email@example.com (Gibbo)
Date: 18 Nov 2002 18:14:45 GMT
Organization: AOL, http://www.aol.co.uk
Subject: Re: Multi-voltage PC switchers -- how?
David Lesher firstname.lastname@example.org wrote:
>PC supplies are getting up there. I wonder how they are now
>The 150w ones [i.e. bottom of the line] regulated on the 5v line,
>and just let the 12v and others tag along. [Maybe it was the 12v;
>but in any case..]
>But a friend has a new one that's something like 20A at 3.3v, 40A
>at 5v, 15A at 12v, and a little -5/12 etc. (I expect twist-lock 30
>amp plugs al-la PDP-11's Real Soon...) The first three claim
>Pondering same, I was wonder how it's done. You can have one
>rectifier/filter; that's easy. But do you have 3 separate
>oscillators/three separate PWM regulators; or do you make
>high frequency (well, in THIS context..) AC and distribute
>and use that....or?
Mutual inductors can massively increase cross regulation. This usually takes
care of the +/- 12 volt rails.
For very high current supplies the usual solution would be to use a magnetic
amplifier post regulators or another buck regulator.
But I'm guessing. Just saying what seems practical. I don't know how they do it
in the PC supplies as I've never looked at them.
But I do know there's a real expert on PC supplies on this NG and I imagine
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup