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From: cook@gaia.UUCP (Forrest Cook)
Newsgroups: sci.electronics
Subject: Telephone Ring Detector IC?
Message-ID: <333@gaia.UUCP>
Date: Tue, 27-Oct-87 19:36:13 EST
Article-I.D.: gaia.333
Posted: Tue Oct 27 19:36:13 1987
Date-Received: Fri, 30-Oct-87 05:26:48 EST
Organization: Gaia Corp, Boulder, CO
Lines: 14
Keywords: Who Makes Them?

Does anybody out there have any experience with Telephone ring detector
chips?  The circuit that I have used is:

O----/\/\/-----(| |)---   <-light->  ---(/\/\/)------O 5 Volts
     150K	NE-2  |              |   CdS Cell
Phone Line	      |              |---------------O To Schmitt Trigger
		      |              |   2K
O----------------------              ----/\/\/-------O Ground

This works but is large and ugly.  Who makes the ring detector chips
and are they very reliable?

Thanks in advance,
Forrest Cook