Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!pyrdc!pyrnj!bartal!phillip From: phillip@bartal.CRLABS.COM (Phillip M. Vogel) Newsgroups: sci.electronics Subject: Re: DC power supply for IBM PC? Message-ID: <30@bartal.CRLABS.COM> Date: 29 May 89 12:14:07 GMT References: <4682@drivax.UUCP> <1989May28.214142.26384@utzoo.uucp> Reply-To: phillip@bartal.CRLABS.COM (Phillip M. Vogel) Organization: Bartal Design Group, Inc. - Englewood, NJ Lines: 40 In article <1989May28.214142.26384@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >In article <4682@drivax.UUCP> macleod@drivax.UUCP (MacLeod) writes: >>... Since the internal AT power supply takes >>120Vac to produce +5Vdc @20A, -5Vdc @.5A, +12Vdc @8A, and -12Vdc @.5A, >>shouldn't it be relatively easy to cook up a modification to the power >>supply (or a replacement for it) which would run directly from 12Vdc power? > >Sorry, not so. For one thing, don't confuse the 12Vdc from your power [stuff deleted] >but if you want a simple circuit it's going to be very >inefficient and fairly bulky (translation, it will need considerably better >cooling than your current supply and probably won't fit in the same housing). [more stuff deleted] >NB I am not an expert in this and may have missed something subtle. >-- Henry, I'm afraid you're way out of your field (what field is yours, anyway?). While it may be slightly tricky to get +12V regulated out of a car battery (ie. you can't just use a 7812), there's those of us who know how to design supplies with something other than 3 terminal regulators. I'm not saying the job is trivial, but it certainly is not unreasonably difficult. >Van Allen, adj: pertaining to | Henry Spencer at U of Toronto Zoology >deadly hazards to spaceflight. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Van Halen, adj: pertaining to deadly hazards to your ears. Sorry about that, but I'm not too witty this early in the A.M. Really, Henry, your input to the net is highly valued, and many of us are asking the question, "just who is this Henry Spencer, and how does a guy who seems knowledgable on so many subjects end up in the zoology department?", especially when I never have seen you post in sci.bio??? -- Phillip M. Vogel, President | #include Bartal Design Group, Inc. Englewood, NJ | (201)567-1343 FAX:(201)568-2891 UUCP: killer!crlabs!bartal!phillip | Domain: phillip@bartal.crlabs.com