didn't someone tell me that telco equipment had 40vdc racks once?

[Oren Beck]

On Dec 18, 2007 8:22 PM, David Nicol <davidnicol at gmail.com> wrote:

> I've been suggesting this kind of thing for years
>
> http://www.news.com/8301-11128_3-9835281-54.html?part=dtx&tag=nl.e433
>
>
> --
> Looking back, I realize that my path
> to software as a career began at the
> age of seven, when someone taught
> me to count in binary on my fingers.
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Actually, the standard telecom voltage has been 48 vdc,
With two interesting triviata.

The term "Ring" refers  to the ring of a plug that is the direct ancestor of
what we use for musical instruments today

So "Tip" refers to the TIP of that same plug.

The other odd details of note are  that in the original "Bell System" most
phone wiring for POTS was on either Red Green Yellow 3w cable or Red Green
Yellow Black 4c wire.

The oldest connections used Red and Green for the talk and dial circuit and
the Yellow was often used for either Ringing or party line user
identification -where the GREEN wire was POSITIVE and called TIP.
The RED wire was Negative and called Ring
The Yellow wire was called SLEEVE or the rearmost part of the plug  with
BLACK as a second sleeve in my recall of the systems. Curiously when I fact
checked myself the Yellow wire use seemed to be regional and not totally
consistent even in the same region..


Oren Beck

816.729.3645
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