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From: sukenick@ccnysci.UUCP
Newsgroups: net.sci
Subject: Re: Choice of voltage?
Message-ID: <232@ccnysci.UUCP>
Date: Mon, 3-Mar-86 18:16:22 EST
Article-I.D.: ccnysci.232
Posted: Mon Mar  3 18:16:22 1986
Date-Received: Fri, 7-Mar-86 06:02:31 EST
References: <drutx.107>
Reply-To: sukenick@ccnysci.UUCP (George )
Organization: City College of New York
Lines: 14
Summary: ?why 60 Hz, -48v phone, what is phone ground material?

>>	Does anyone know why 60hz was chosen as the standard frequency
>>	for the AC power distribution system in North America??
>
>Along the same lines, why -48 volts for telephone lines.  I understand
>the negative voltage is to prevent loss of copper.  But 48?
				^^^^^^^^^^^^^^
Negative with respect to what? If its negative to prevent
some degradation (oxidation,perhaps?)of the copper,
 then what is the ground wire composed of?


				-george

Alright, enough questions here! how about some answers! *)