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From: AWalker@RED.RUTGERS.EDU (*Hobbit*)
Newsgroups: comp.dcom.telecom
Subject: Ring detection
Message-ID: <12300549863.66.AWALKER@RED.RUTGERS.EDU>
Date: Thu, 7-May-87 16:58:27 EDT
Article-I.D.: RED.12300549863.66.AWALKER
Posted: Thu May  7 16:58:27 1987
Date-Received: Sat, 9-May-87 10:06:39 EDT
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The following

              .01uF      +-------+
Line ----------||--------|AC    +|-------->
                         |       |
Line ----------||--------|AC    -|-------->
              .01uF      +-------+
              200V      Bridge rect.


will generate a voltage across the + and - of the bridge when ring voltage
appears across the line.  It will also isolate the line from your downstream
equipment.  You don't have to wait 14 weeks for a mess of diodes.

This as given may be a little *too* sensitive and trigger on small voltage
edges -- an appropriate application of R and C after the bridge can cut
this down some.

_H*
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