[Asterisk-Users] Line Override Device

[Steven Critchfield]

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On Sun, 2003-07-13 at 13:16, Shawn L. Djernes wrote:
> Hello,
>  
> I am trying to solve a problem that I can foresee when I deploy
> Asterisk into a few SOHO situations soon.  In Nebraska and in my area
> of Western Pennsylvania we have violent thunderstorms in spring and
> summer and sometimes very heavy wet snow in Winter.  Both type of
> event will take out the power of a period of 30sec to 36-hours.  So no
> UPS system would be able to handle a system for over an hour.  So what
> I am wanting to build or buy is a device that when normal power is on
> and we have battery output on a FXS that the line dumb analog phone
> talks to asterisk, but when the UPS has shutdown and our phone system
> goes down, thus no battery signal on the line it switches that same
> dumb analog phone to the outside Analog trunk.  This was the users can
> make and receive any emergency calls while the power is out. 

You can build a UPS for that, but the better option here is to attach a
phone to the phone side of the X100P that is always connected to the
POTS line so that even when the computer goes down you can send and
receive calls.

> I have the basic concept of how this thing should work but not enough
> knowledge of telephone electronics to build it.  I think this should
> be an essential part of any PBX that supports analog lines and would
> be willing to pay a reasonable price for it.
>  
> Next sort of on the same topic.  Does anyone have a diagram or know of
> some where you can buy a single or dual port Cisco power inserter.  I
> want to put the Power Adapter for my 7960 over on the UPS so that the
> phone on my desk doesn't die right away when the power flickers or
> goes out.  My battery a APC Back UPS Pro 650 holds the Asterisk server
> (Athlon 850 w/ 384 mb ram, X100P, Netgear FA311 10/100, Kinkston 10mb
> ne2k-pci clone, S3 Savage clone video, IBM 15GB, IBM 60GB, IBM 80GB
> IDE drives and four fans) Westtel DSL modem, Netgear 10mb hub (outside
> interfaces), Intel Pro 8-port managed switch (inside interfaces) for
> 25-30 minutes and that is usually enough for the power company
> equipment to reset around here.

The specs are available on the net to show you how to wire POE (Power
over ethernet). In fact I did my own so I can use the 7960 before we
found a suitable wall wart. Basicaly all I did was punch down a keystone
with the ethernet data lines, then punched down the power lines so that
one side had power and the other didn't so I didn't chance blowing up my
switch that was made before they thought of doing POE. I used the power
supply from a CAC AB1 that had the ringer module broke on it. It
produces 1amp of 48volts and was more than adequate for the 7960. If I
had a lot of phones to power, I have a 6amp 48volt PSU from a Premisys
channel bank that I picked up at a hamfest for $10.

BTW, for the UPS, we have some powerware UPSs that have plugs for
external batteries. In our former server room we have one with 5 car
battery sized batteries attached to it. We feel we had about a 10 hour
run time. 

-- 
Steven Critchfield <critch at basesys.com>