Article View: mod.telecom
Article #149active-line indicator
From: *Hobbit*
Date: Tue, 22 Oct 1985 17:52
Date: Tue, 22 Oct 1985 17:52
19 lines
1333 bytes
1333 bytes
Line ------------------------------------------------> to devices
100 ohms
+--/\/\/\/\/\/--+
| |
Line ------+------|<|------+-------------------------> to devices
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+------|>|------+
LED
The thing in the middle is a regular diode pointing the other way. If you
want to get fancy, you can use a green LED pointing one way and a red one
pointing the other [in place of the regular one], which will indicate line
polarity. The 100 ohm resistor passes some of the line current and protects
the LEDs. This will give you an almost indiscernible current drop at the
phone end...
_H*
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Technical Details
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site ucbvax.BERKELEY.EDU Path: arc1-ca.pugleaf.net!utzoo!decvax!decwrl!ucbvax!red.rutgers.edu!AWalker From: AWalker@RED.RUTGERS.EDU (*Hobbit*) Newsgroups: mod.telecom Subject: active-line indicator Message-ID: <12153191012.61.AWALKER@RED.RUTGERS.EDU> Date: Tue, 22-Oct-85 13:52:07 EDT Article-I.D.: RED.12153191012.61.AWALKER Posted: Tue Oct 22 13:52:07 1985 Date-Received: Wed, 23-Oct-85 13:24:13 EDT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 19 Approved: telecom@ucb-vax.arpa