UPS monitor (was: Re: Shayne's Guild clock [was: Re: [plug] usb2 woody])

[Shayne O'Neill]

yeah. I've been contemplating building a little device out of a basic
stamp and some relays or something.

might be cheaper just to get a modern nifty shoebox ups.

------------------------------------
"Must not Sleep! Must warn others!"
-Aesop.
Shayne O'Neill. Indymedia. Fun.
http://www.perthimc.asn.au

On Sat, 15 May 2004, Harry wrote:

> On Sat, 15 May 2004 21:28:20 +0800 (WST) "Shayne O'Neill"
> <shayne at guild.murdoch.edu.au> wrote:
>
> > yeah. thats exactly what happens. :(
> >
> > its actually on a ups, but murdoch uni seems to get some unholy long
> > poqwe outs and its a funky old ups that doesnt have any warning system
> > for the server.
>
> Hi Shayne
>
> Here's an idea. How about plugging a simple interface into the same power
> point as feeds the UPS. This sends a signal to the server (lowers DTR on a
> serial port or something) when the power goes away. If you know how long
> the UPS normally lasts, just write a little app that watches the DTR line.
> When it drops, run a timer to keep the server up for maybe 75% of UPS run
> time then elegantly shut it down.
>
> The interface could be as simple as a DC plug pack connected to a relay
> with the relay contacts wired across the CTS and DTR pins (and appropriate
> driver calls to raise one and monitor the other). A small relay may fit
> inside a DB25 cover. Electrical isolation using a relay is also Good(tm).
>
> Or use the UCC door sense method. The switch (or relay contact) is between
> the transmit and receive pins of the serial port. If you send a char and it
> doesn't return, the relay is open which means the power has gone off.
>
> It'd be fun and has the added bonus that PLUGers will stop going on and
> on (and on .. ) about times on your email ;-)
>
> Harry
>
> --
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