Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 (Tek) 9/28/84 based on 9/17/84; site orca.UUCP
Path: utzoo!watmath!clyde!cbosgd!ihnp4!hplabs!tektronix!orca!philb
From: philb@orca.UUCP (Phil Biehl)
Newsgroups: net.analog,net.ham-radio
Subject: Telephone ring detector
Message-ID: <2032@orca.UUCP>
Date: Tue, 18-Mar-86 12:26:12 EST
Article-I.D.: orca.2032
Posted: Tue Mar 18 12:26:12 1986
Date-Received: Fri, 21-Mar-86 05:01:21 EST
Distribution: na
Organization: Tektronix, Wilsonville OR
Lines: 20
Xref: watmath net.analog:716 net.ham-radio:3951


	I'm in the process of adding telephone capabilities (autopatch)
	to the UHF ham repeater I am working on. I would like to be
	able to detect the ringing current produced by an incoming
	call. What I need is a CMOS compatible signal indicating that
	ringing current is present on the drop. That is, a pulse for
	every ring burst.

	I would like to have as much isolation from the drop as possible
	and have been considering optoisolators to connect the logic to
	the line. 

	I would like to get a consensus on your favortie ring current 
	detector. Please mail or post responses. Thanks much.

	Phil Biehl
	(503) 685-2122
	Tektronix Inc., Wilsonville OR

	tektronix!orca!philb