Path: utzoo!attcan!uunet!pyrdc!netsys!vector!nobody From: killer!killer!lll-crg!csusac!polyslo!pbowden@EDDIE.MIT.EDU (Pete Bowden) Newsgroups: comp.dcom.telecom Subject: Re: In-use light Message-ID: Date: 1 Nov 88 01:26:07 GMT Sender: chip@vector.UUCP Organization: Cal Poly State University -- San Luis Obispo Lines: 36 Approved: telecom-request@vector.uucp X-Submissions-To: telecom@bu-cs.bu.edu (TELECOM Digest Coordinator) X-Administrivia-To: telecom-request@vector.uucp (USENET Telecom Moderator) X-TELECOM-Digest: volume 8, issue 175, message 4 I have wired an "in-use" light into a 9-line key telephone so that I can tell if any telephone units (or mostly modems in my case) were in use (I have 9-lines in my residence -- 7 of which going into a BBS). Anyway, I didn't design the circuit and I don't have it right here -- but if you wish to experiment here's what it included... 1) 10 micro ferad capacitor 2) a zener diode (around 10 volts if I am remembering) 3) a light (whatever the light is in the standard key telephone is what I am using) On the positive wire (if it doesn't work on the first wire, try the second) before the telephone units which you wish to have light up the light install the capacitor and diode in parallel with the line, along with the light. We'll TRY a drawing... ----LIGHT---- | | --Capacitor-- | | ----Zener---- | | +------------------------------------X (Telephone line...) > Telephone Unit(s) ------------------------------------X - This circuit does use a slight amount of power and you may have problems if you try to run several lights -- but it doesn't seem to affect the quality of my line in any noticable amount. A friend who IS more into the electronics recommended the use of an optal isolator in place of the Capacitor and Zener but didn't go into detail. ___ -'/ > / |"Pete" Bowden, P.O. Box 905, Santa Maria, CA 93456-0905 /___/___ --/--___ | Sysop--LOIS BBS 805-928-6969 (4 public dialups) / /___> / /___> | / _/\____/\_/\____/ | ...{csun,sdsu}!polyslo!pbowden You have PLENTY of time to finish this assignment. What do you mean you have other classes?