Path: utzoo!telecom-request Date: Mon, 27 May 91 14:22:52 PDT From: Steve Pershing Newsgroups: comp.dcom.telecom Subject: Re: Ringing Tones Around the World Message-ID: Organization: Questor - Free Internet/Usenet*Vancouver*BC::+1 604 681 0670 Sender: Telecom@eecs.nwu.edu Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 402, Message 8 of 9 Lines: 28 john@zygot.ati.com (John Higdon) writes: > If you really want your phones to ring with a cadence separate from the > one supplied by your central office, then you will have to invest in > some sort of phone system, be it a PBX, hybrid, or a key system. Not to belabour the point, but there are tone-ringer chips from many chip manufacturers which can be relatively easily configured to produced whatever ringing cadence one wants, given a bit of electronic knowledge. Chips from Motorola and Mitel come to mind. I think a simple circuit consisting of a CMOS 555-type timer powered by a bridge rectifier across the telephone line (and isolated by means of neon lamp) would do the job. The 555 could be used to trigger and/or power the Tone Ringer chip as I think it can supply around 20ma current (if memory serves me correctly). Steve Pershing, System Administrator The QUESTOR Project: FREE Usenet News/Internet Mail; Sci, Med, AIDS, more : Internet: sp@questor.wimsey.bc.ca : POST: 1027 Davie Street, Box 486 : Phones: Voice/FAX: +1 604 682 6659 : Vancouver, British Columbia : Data/BBS: +1 604 681 0670 : Canada V6E 4L2 :