Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!wuarchive!usc!zaphod.mps.ohio-state.edu!mips!daver!bungi.com!news From: jonb@vector.dallas.tx.us (Jon Buller) Newsgroups: comp.sys.nsc.32k Subject: Re: pc532 power use Message-ID: Date: 14 Jul 90 00:51:30 GMT References: <> Sender: news@daver.bungi.com Lines: 23 Approved: news@daver.bungi.com > The board running at 25 Mhz draws about 2.5 Amps of +5 (2.1 if you are > using 2692 CMOS DUARTs). The +/-12 V supply only requires a few milliamps. > Note that some switching power supplies will refuse to come up without > additional load on the +12V rail - such as a disk drive. A typical IBM AT > style power supply provides 20 to 25 Amps of +5, and 10 Amps or so of +12. > -12 is usually 500 mA. > > Besides 2.5 A is about 12.5 watts - not back for a 12 MIPS machine! Well put, I wasnt thinking of all that speed, memory, etc. (my projects are usually smaller. The modems I program at work draw about 150mA max. and my sound digitizer runs off my Mac's serial port drivers...) I got the 2A number by remembering the 2 1A fuses which power the SCSI busses not the board itself. But this tells me just what numbers to put into the power supply on the test bench before putting it in the pc case I bought. I'd much rather have my board pull 2.5A at 2V if I did something wrong rather than 20A at 5V and let all the smoke that runs everyting out of the system. I want to conserve all that magic smoke 8-) ---------------------------------------------------------------------- Jon Buller jonb@vector.dallas.tx.us ..!texbell!vector!jonb FROM Fortune IMPORT Quote; FROM Lawyers IMPORT Disclaimer;