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From: hes@ecsvax.UUCP (Henry Schaffer)
Newsgroups: net.dcom
Subject: Re: Re: Need surge protectors for phone line
Message-ID: <125@ecsvax.UUCP>
Date: Tue, 6-Aug-85 22:19:14 EDT
Article-I.D.: ecsvax.125
Posted: Tue Aug  6 22:19:14 1985
Date-Received: Sun, 11-Aug-85 04:05:44 EDT
References: <545@wdl1.UUCP> <228@kitty.UUCP>
Organization: NC State Univ.
Lines: 13

> >       Remember Data Access Arrangements?  Those boxes the phone company
> > used to make you buy to ``protect the telephone system''?  
>      Now all of these functions have been
> replaced with solid-state optocouplers which are still much more vulnerable
> to damage that the old relay counterparts.
> 
> 	Larry Lippman
An auto answer modem we've used has a full-wave
bridge rectifier across the line.  I think it's used to detect
the ringing voltage, and probably also to make ring-tip 
reversals make no difference.  The problem is that it tends to
get blown during lightning weather.
--henry schaffer