[Tfug] Yet another poser

[jblais]

> -----Original Message-----
> From: tfug-bounces at tfug.org [mailto:tfug-bounces at tfug.org]On Behalf Of
> George Cohn
> Sent: Thursday, September 20, 2007 6:12 PM
> To: Tucson Free Unix Group
> Subject: Re: [Tfug] Yet another poser
> So gigabit CAN be POE as well.
>
> This is really old technology.  For years, analog telephony has been
> multiplexing power as well as analog audio on the same two pairs.
>
> It gets even worse.  Normally, telephony puts about 48 volts DC on the
> pair to power the phone, something like 40 ma maximum.  However, when
> someone calls you, they superimpose a 20 Hz 90-105 volt A/C signal on
> the same pair to ring the bell.
>
> George Cohn
>


I guess this is how X-10 stuff works -
I also remember an old house where we lived, where only one phone wire came
into the house, the circuit was closed through ground, and from the
grounding block there were 2 wires through the house.

joe