----- Original Message -----
From: "Larry Kayser" <[email protected]>
One final point, if you doing the ADSL setup yourself. The North American
ADSL/HDSL systems are largely line powered. It takes a major effort to
deliver 1W of DC to the far end of a long local loop so they regularly see
both sides of the 120VDC office battery for a total of nearly 250 V DC on
the loop from the central office. This can cause some very strong
reactions when ones fingers get into the stuff so if your doing it
yourself
it is best to be careful, many of us have forgotten how to live with
higher
voltages with all this 5 and 12 v stuff hi.
If I recall correctly, UK practice was to run Strowger (TXS),
reed-electronic (TXE) and crossbar (TXK) exchange equipment all off 50V dc.
I do not know what later technologies such as System X used, but I believe
there was a Health and Safety aspect which would tend to encourage the use
of lower rather than higher voltages. Does anybody have more recent
knowledge of this?
Regards,
John Rabson
G3PAI
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