[Asterisk-Users] Overhead Paging

[Ejay Hire]

Traditional overhead paging systems are a little more
complicated than they first appear.  It's not just speakers
and a centralized amplifier.  They would have too much cable
loss if done that way.  Instead, they use a centralized
power source, and amplifiers at each speaker unit..  The one
I just took apart used 3 wires in series to the overhead
speakers, and each speaker unit had an independent volume
control and an onboard transformer on the unit.  One of the
wires (black) carried 60V.  Green was ground.  The last wire
(smaller than the rest) was the audio signal.   The audio
signal ran into the transformer and modulated the 60V
signal, and the output went to the speaker.  Neat
contraptions.  Don't hurt yourself.

-ejay

> -----Original Message-----
> From: asterisk-users-bounces at lists.digium.com 
> [mailto:asterisk-users-bounces at lists.digium.com] On Behalf
Of 
> Chris Shaw
> Sent: Thursday, August 26, 2004 5:35 PM
> To: Asterisk Users Mailing List - Non-Commercial
Discussion
> Subject: Re: [Asterisk-Users] Overhead Paging
> 
> ----- Original Message -----
> From: "Brian Pavane" <asterisk-users at brianpavane.org>
> To: "Chris Shaw" <chriss at watertech.com>; "Asterisk Users 
> Mailing List -
> Non-Commercial Discussion"
<asterisk-users at lists.digium.com>
> Sent: Thursday, August 26, 2004 2:39 PM
> Subject: Re: [Asterisk-Users] Overhead Paging
> 
> 
> > Chris,
> >
> > What you're talking about is exactly what I'm looking
for.  
> I'm interested
> in
> > the middleware that would sit between the speakers and
the 
> IAD.  I have
> found
> > the Bogen TAMB device -- however I was wondering if
anyone had any
> experience
> > with this box.  How many speakers can you power off of
the 
> unit without
> needing
> > an external amp, etc...
> >
> > -Brian
> 
> lol those would be electrical questions... Not sure how to

> answer those, it
> would depend on power output of the TAMB device and how
much 
> current draw
> and wattage the speakers require... I know this would work

> though, as long
> as the receiver/amplifier has an FXO interface and not an
RCA 
> jack like you
> would find on a stereo system or CD player...
> 
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