Xref: utzoo comp.unix.questions:25947 comp.unix.sysv386:947
Path: utzoo!attcan!uunet!munnari.oz.au!uniwa!DIALix!bernie
From: bernie@DIALix.oz.au (Bernd Felsche)
Newsgroups: comp.unix.questions,comp.unix.sysv386
Subject: Re: Cheap or free auto-shutdown setup
Summary: This is $30 worth of parts...
Message-ID: <581@DIALix.oz.au>
Date: 3 Oct 90 05:03:58 GMT
Expires: 30 Oct 90 00:00:00 GMT
References: <1990Sep29.220137.6550@intek01.uucp-> <1030@bilver.UUCP> <257@bongo.UUCP>
Reply-To: bernie@DIALix.oz.au (Bernd Felsche)
Followup-To: comp.unix.questions
Organization: DIALix Services, Perth Western Australia
Lines: 34

In article <257@bongo.UUCP> julian@bongo.UUCP (Julian Macassey) writes:
[previous qoute deleted]
>	So to summarise, here is what needs to be done:
>
>1.	Identify a power outage
>
Easy via an RS-232 line monitor, of any religion you like.

>2.	Start shutdown
>
Shell script.
>3.	Abort shutdown, or reboot if power returns within a specified 
>period.
>
Shell script.
>4.	Switch off machine after shutdown is successful
>
RS-232 DTR line can be dropped, allowing a relay to drop out after a
nominal interval... no more power.

>5.	Switch machine back on after power has been restored for a certain 
>length of time.

Monitor power presence and after a safe delay (for the UPS to come
to a usable charge state), enable the computer's power relay.

All the above hardware can be put together with a few CMOS logic chips,
timers and passive components... oh and one or two relays.  Hardware
cost is about $30, maybe less.  Design time about 1 day.
Construction, depends.

If you prefer, send me US$3000 and I'll make one for you :-)

bernie