Date: Wed, 14 May 2003 09:33:07 +0100 From: Axel Simon <A.Simon@ukc.ac.uk> To: Ivo Hazmuk <ivo@vutbr.cz> Cc: freebsd-hardware@freebsd.org Subject: Re: ATX boards and restart after power failure Message-ID: <20030514083307.GB4184@myrtle.ukc.ac.uk> In-Reply-To: <20030514070519.E68371-100000@hippo.cis.vutbr.cz> References: <3EC1ADAC.3050107@lockie.ca> <20030514070519.E68371-100000@hippo.cis.vutbr.cz>
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On Wed, May 14, 2003 at 07:17:12AM +0200, Ivo Hazmuk wrote: > > I have an Asus P5A r1.04 mainboard that I want to use for a server but > > it does not reboot after a power failure. > > r1.06 of the P5A does but that doesn't help me. > > Now I have 5 or 6 pieces of this card. If you want I can send it to you. > But I don't know the cost. It was about 60 US$. Indeed, I think you need to generate a pulse after the power comes up and that pulse has to stop within a specific time. But the most luxury version of doing this is a NE555 ($0.12) used as a mono-flop (I know it sounds funny, but that's what it's called when you only want to generate a single pulse.). http://www.national.com/ds.cgi/LM/LM555.pdf (page 7 top left) Connect an RC combination to pin 2 (C to +5V and the R to ground). Calculate this to fall down to 2/3 of +5V which starts the timer. The other RC combination can be choosen so that it gives a 1s pulse according to the diagram on the right. You might need to invert the output, depending if you power switch connects to ground or to +5V. Hope this helps, Axel.
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