Path: utzoo!attcan!uunet!pyrdc!netsys!vector!nobody From: tedk@ihuxv.ATT.COM (Kekatos) Newsgroups: comp.dcom.telecom Subject: Re: sensitive relay wanted Message-ID: Date: 5 Oct 88 15:17:36 GMT Sender: chip@vector.UUCP Reply-To: tedk@ihuxv.UUCP (55624-Kekatos,T.G.) Lines: 29 Approved: telecom-request@vector.uucp (USENET Telecom Moderator) X-TELECOM-Digest: volume 8, issue 153, message 5 X-Submissions-To: telecom@xx.lcs.mit.edu (Mailing List Coordinator) X-Administrivia-To: telecom-request@vector.uucp (USENET Telecom Moderator) {{{ I have edited down the quoted material in this message. -chip }}} In article wheels@mks.UUCP (Gerry Wheeler) writes: >I'm looking for a relay to place in series with a telephone which will >open (or close) when the set is offhook. My comments about using a single relay coil to detect loop-current, that would not work because you can not draw enough current from the phone-line, were if the relay is connected in parallel with the phone line. -------- I have several phone extensions in my home, and several other devices that use the phone lines (modems). I wanted to build a device that detects off-hook and lights a LED on each phone. (The modem are smart enough to check for dial-tone). The only circuit that worked (and worked quite well) is a circuit with several transistors and a battery to light the LEDs. I use one of those self-blinking LEDs from Radio shack. I never tried connecting a reply coil in series with a single phone. ------ Ted G. Kekatos UUCP: ..!att!ihuxv!tedk (312) 979-0804 AT&T Bell Laboratories, Indian Hill South, IX-1F-460 Naperville & Wheaton Roads - Naperville, Illinois. 60566 USA