15 Feb
2013
15 Feb
'13
7:57 p.m.
I am thinking of something like a mobile charger that would plug in a
regular 3-pin plug at one end and a computer at the other, and some
software/sensor combo that would read the (DC) voltage at the computer end.
If there is no voltage, there is no power in the mains and ergo - we are in
the middle of a power outage, so take action. Know of something along these
lines?
(idea is to detect power failures, while powered by a "dumb" UPS unit - one
that cannot communicate with the a computer. Any other
solutions/suggestions?).
Binand
16 Feb
16 Feb
1:45 a.m.
On Fri, Feb 15, 2013 at 7:57 PM, Binand Sethumadhavan <binand(a)gmail.com> wrote:
I am thinking of something like a mobile charger that
would plug in a
regular 3-pin plug at one end and a computer at the other, and some
software/sensor combo that would read the (DC) voltage at the computer end.
If there is no voltage, there is no power in the mains and ergo - we are in
the middle of a power outage, so take action. Know of something along these
lines?
(idea is to detect power failures, while powered by a "dumb" UPS unit - one
that cannot communicate with the a computer. Any other
solutions/suggestions?).
Good idea. You could use one of those AC Mains to USB
adapter/charger; which I think gives out 5V on the USB power line. A
USB cable into the computer USB port should be a good starting.
-- Arun Khan
9:53 a.m.
On Sat, Feb 16, 2013 at 1:45 AM, Arun Khan <knura9(a)gmail.com> wrote:
A laptop already detects that using battery charging or not. I'm not sure
how. You can rig that power module from a laptop to make a makeshift UPS
that can do that. But I guess here you are looking at UPS for
Desktop/Servers. In which case you will need to spend a USB port. However
the standard on power grids is PLC. I remember people doing final year
engineering projects on this topic. Here is an intro article on the topic.
http://en.m.wikipedia.org/wiki/Power_line_communication
The USB will work for sure to detect power failure but how will you
communicate to "dumb" ups from the computer? Curious.
--
Sanket
On Fri, Feb 15, 2013 at 7:57 PM, Binand Sethumadhavan
<binand(a)gmail.com>
wrote:
> I am thinking of something like a mobile charger
that would plug in a
> regular 3-pin plug at one end and a computer at the other, and some
> software/sensor combo that would read the (DC) voltage at the computer
end.
> If there is no voltage, there is no power in the
mains and ergo - we
are in
> the middle of a power outage, so take action.
Know of something along
these
> lines?
>
> (idea is to detect power failures, while powered by a "dumb" UPS unit -
one
that cannot
communicate with the a computer. Any other
solutions/suggestions?).
Good idea. You could use one of those AC Mains to USB
adapter/charger; which I think gives out 5V on the USB power line. A
USB cable into the computer USB port should be a good starting.
-- Arun Khan
--
http://mm.ilug-bom.org.in/mailman/listinfo/linuxers
12:03 p.m.
On Sat, Feb 16, 2013 at 9:53 AM, Sanket Shah <88.sanket(a)gmail.com> wrote:
The USB will work for sure to detect power failure but how will you
communicate to "dumb" ups from the computer? Curious.
Make take on this question - the UPS is dumb we cannot communicate
with it at all. I guess, the idea here is to initiate a proper system
shutdown (file system integrity etc.) when the power goes down. The
"dumb" UPS is *not* giving any info at present.
With a solution like this, the OS would detect that mains power has
gone and that it is running on battery back up. It could take proper
action per the configuration - e.g. wait X mins. poll again and if
still down then do a poweroff etc.
-- Arun Khan
9:57 a.m.
On 16-02-2013 01:45, Arun Khan wrote:
On Fri, Feb 15, 2013 at 7:57 PM, Binand Sethumadhavan
<binand(a)gmail.com> wrote:
-------------- Complex Idea
------------------------------------------
Generally an UPS will have a led indicator of the power source AC/Battery
check this
http://electronics.stackexchange.com/questions/26101/connect-a-light-sensor…
now you can use the frequency generated as an input to the line-in of the pc
-------------- Simple Idea ------------------------------------------
Use an electomagnetic switch which switches on when the magnet is off
This can be adapted to setting a signal on the USB/Serial Port
Surya Pratap
I am thinking of something like a mobile charger
that would plug in a
regular 3-pin plug at one end and a computer at the other, and some
software/sensor combo that would read the (DC) voltage at the computer end.
If there is no voltage, there is no power in the mains and ergo - we are in
the middle of a power outage, so take action. Know of something along these
lines?
(idea is to detect power failures, while powered by a "dumb" UPS unit - one
that cannot communicate with the a computer. Any other
solutions/suggestions?).
Good idea. You could use one of those AC Mains to USB
adapter/charger; which I think gives out 5V on the USB power line. A
USB cable into the computer USB port should be a good starting.
-- Arun Khan 
1 Apr
1 Apr
9:01 a.m.
One way to do that is to use a USB Hard disk enclosures that requires AC
power. Connect this enclosure to mains and add a cheap / spare SATA desktop
HDD.
With a cron job, a shell script can check presence of this HDD (E.g. lsusb
| grep "device-id-here") every minute. If this HDD is not present, shutdown
can be initiated by the same script.
Similarly, you can attach a cheap / spare router (would cost 400 - 900 Rs)
to AC mains and check reach-ability of this router to determine presence of
power in mains.
On Fri, Feb 15, 2013 at 7:57 PM, Binand Sethumadhavan <binand(a)gmail.com>wrote;wrote:
(idea is to detect power failures, while powered by a "dumb" UPS unit - one
that cannot communicate with the a computer. Any other
solutions/suggestions?).
Binand
--
http://mm.ilug-bom.org.in/mailman/listinfo/linuxers
4 Apr
4 Apr
3:39 p.m.
On 1 April 2013 09:01, Shamit Verma <subs.linux.mum(a)vshamit.com> wrote:
One way to do that is to use a USB Hard disk
enclosures that requires AC
power. Connect this enclosure to mains and add a cheap / spare SATA desktop
HDD.
With a cron job, a shell script can check presence of this HDD (E.g. lsusb
| grep "device-id-here") every minute. If this HDD is not present, shutdown
can be initiated by the same script.
Similarly, you can attach a cheap / spare router (would cost 400 - 900 Rs)
to AC mains and check reach-ability of this router to determine presence of
power in mains.
Nice and cheap ideas :)
Regards,
Pavithran
6:20 p.m.
On 1 April 2013 09:01, Shamit Verma <subs.linux.mum(a)vshamit.com> wrote:
One way to do that is to use a USB Hard disk
enclosures that requires AC
Similarly, you can attach a cheap / spare router (would cost 400 - 900 Rs)
to AC mains and check reach-ability of this router
Pretty nifty ideas. My office LAN has two servers, a switch and a Wifi box.
The former three are on UPS but the last isn't, so one would think that I
could use it for this purpose. But no, I have trained my staff to power off
the Wifi box when leaving for the day. I need to evaluate whether to
"untrain" them or plan something else, but along these lines (we are
getting a printer next week which I don't plan to put on UPS, perhaps it
would be a good candidate).
Thanks for all the suggestions, folks.
Binand
5 Apr
5 Apr
3:49 p.m.
On 4 April 2013 18:20, Binand Sethumadhavan <binand(a)gmail.com> wrote:
"untrain" them or plan something else, but
along these lines (we are
getting a printer next week which I don't plan to put on UPS, perhaps it
would be a good candidate).
Not a good idea to use a device (eg. printer) that may be switched off
every once in a while. Unless you plan to stop your scripts every time
you service the printer. Reachability to a cheap netwrok device which
will not be used for anything else appears to be a better approach. I
remember streaming mp3's across all the segments of an old network. If
the music ever stopped it meant that some part of the network had
crashed. It was fun while it lasted :)
-gabin
--
They pay me to think... As long as I keep my mouth shut.
6 Apr
6 Apr
4:19 p.m.
On 5 April 2013 15:49, gabin kattukaran <gkattukaran(a)gmail.com> wrote:
Not a good idea to use a device (eg. printer) that may
be switched off
every once in a while. Unless you plan to stop your scripts every time
you service the printer. Reachability to a cheap netwrok device which
will not be used for anything else appears to be a better approach.
You are right, but my LAN has a total of 5 devices (apart from user
PC/laptop/phones) - 2 servers, 1 switch, 1 Wifi and 1 printer. Since
the servers and switch are on UPS, they are ruled out. I really want
to continue with the discipline of switching off the Wifi box at the
end of the day. Using the printer is my best bet - after all, I don't
mind a few Type I errors in this system.
I will share the script(s) I plan to write for this.
Binand
3896
days inactive
3946
days old
9 comments
7 participants
participants (7)
-
Arun Khan -
Binand Sethumadhavan -
gabin kattukaran -
pavithran s -
Sanket Shah -
Shamit Verma -
Surya Pratap