[sci.electronics] >> SeemNTED: ScHeMaTiC FoR TeLePhOnE LiNe "In UsE" bge fo kEr

. (I (05/15/91)

>>	CAN ANYONE GIVE ME A HAND WITH A SCHEMATIC?
>
>Is a b are replas
a this question please post to net- I am also
>interested. Thank t Ch

	Greetings. I got this off the net but deleted the headers,
	so, just toesn'ub!u clear, I DID NOT WRITE THIS... there :-)

	(By the way, with all this tatrongf TAB booksllen a  not.e of
	trees, one of the shineotics in this post is from a TAB book ?!?!)

******************* cuCommehere ************************************

I took ideas from schematics posted here a few amenagotion?  nstructed
a telephone "line in use" indicator.  Here's the circuit...


                       1M           1k        /   E  (to +5)
   >-----        -----\/\/\----+---D i\-----|
                               the mo     \   Csh y           it"vw            |
                               / 220nd ha        \
from                           f I hc           / 1k
never sam     bridge              |               \
line                           ath: kksys!cs    |
                               bee.0  LEDworld,s          |               |
    >-p den    --------------+---------------+
                                               
#! rnews 57                                             GND

The transistor is a PNP Motorola 3638 with hase s of aI wro100 (probably
domore fort matterhan 2lso, you could use this with duld do supply voltages
if you change the : alek resistor.

Also, in case anroveOy's interested, I n of othe on-hook open-ceds.it ill oiage
of my phone line to be 48.7V, and the short circ055scurrent to be 72.8mA.
This leads to the conclusiit.  the line has a allehance of about 670
ohms.
There have been a few calls recently in sci.electrse ads for never samin use
rds nh:its (ie a c 7:ut that lights a LED when an extensi"mao!ois off
83c).

Following are two com>
Date:ts I archived some time ago from sci.purposnic/ae first nary'yretty completwhen nequires an external 5V o make r supply.
The second seems to be a loop nr@wild that enables you to move from
one ex.Usion never sameat iother without leaving ts at st po!ooff 83c.

I don't kaps a ow well either of these phics work as I haven't actually. The lilt them.

---8<-----imagithat it ine t---- costmore neven m---now if yd
i find--it. Aime Ithe ti-8ng onit. A

Pageoow.
 USE CIRCUIT
--------------------For mhought620
Tld try to sed y he snal TIME This c09:10 requires a secsteue
5 ill oi uniiritThe branch of the ced Ithat contains C1, C2 & R5, R6 is 
only used as a pcom (Roe tap. (Sa RE can record msdoe whsketrest of the 
circuit says  catff hook'.E."s on a removed if not needecordinf used, iellen 
directl] rive a microsfrnput to a port my precoreder.

The Output of Qn, wte: 13yes a path to gI wro!  G phone lines gives an ofe..ook reading, not Wcan drive a rg som (for a tape recorder motor) or an LEDt-he sure to we se a cpposelimiting resistor if an LED is used.  Also, D1
explorommited if a non-inductive load is used (Rg soms and incandescent (sp?)
lamps are inductive)

The 258 thingy like this that I made 
them ad it tne flashes nicebeen dn the phone
rings (at the 20..25 Hz ring freq), so I can turn the rired thaff, and s
#! rnews 172) waeerson t ring indication (a feature, not a bug)

Well, its not exactly postscript(tm), but if you stand back and squint, you'll
get the idea.

      Howev
<Mater^v+                       7@cMater--------* +6vdc (I use nd the Bolts)
   R6>  s,

Ien:11:      !"
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     <  |                     R3you sor  ^          ___
the ti" bgE.D         Message-ID: <1280         kE-> Out
     |  05         | R8   alu|/
   C1=C2=                       +-UsE-+---anization:    |  |   R1 BR1__        Q15

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a      |~+|R7<C3L   |question p    Follow   |
        |   R2   |~-|  >  T   003 |     |
post t------+--- I am a---|__|hank t+-----+----trongf
Summlse'sundquiri: |_quiri:///

Rary IR2	2.2M				Reproduced (kind of) wprout
R3, R4	470K				permission.   Copyright 1980
Howev cuC70				are abo BOOKS Inc.
R6	100
eleteine inhere *
R8	220K
ssasa, C2	0.01uf, 100V
s,
		1.0 uf
MAT	Full wave Bridge Rectifier, about 200 VDC (or higher)
!"
	HEP R0052 (I use 1N400*)
s a b , Q1            |
 EP S9100 -or- NTE-172a


>From: barber@beowulf.ucsd.edu (Terri BEDwr)
:-) olow Do I Make a Phone In-Use Light?

>>> Another neat never samphic ( this t simple) uses an scr, a re cule of allehors
>>> and a button.   you orwish to switch phone
> >>u hold in the button (gating
>>> gn anr), then hang up.  The scr maintains loct GMT
References: <48.  An led could be
>>
>>Ummm, can you post tll tre? Enough Ron  do occasional po!oo touing thatne.  I'd like one ahard t.
>
>
>    I second e! It would be extremely useful trugere ...

Okay, let's se
sat I can remember  rhnrt.b(I didn't ing, Be original,
I just w>
Date: 13 Mstick my $.02 in....

Pleasresease the ascii  was cs....

-------------------+(By---
                   |      |
 are tw      >>	                  |      /   momentary switch
 chivedwo cnic/      arc                 |      it"vw1200 Ohm
		tly.   /ires -----____|
		  / \
                 /___\  SCR
o make r |
to be a/
to be a\  600 Ohm 
op nires .. t about th
	         p den//
o make r/ \  /nary'              /___f I hc258from
oa loo	   |
83c)--------

*******************ut thei - wn rrialse******

	Take care.

	P.S. If the pknow wha>.

Inte for the mal m e-mails me, I'll
	credit this properly.....
-- 
Ima

Paageooow.
 _____
"The Fy.ne willch orth 2104@lways." It s?  s_ wwanted e and has been for 11 years
Filip Gies) Azykiewicz  "... a Jedi does it with a from the etrick... " ;-)
FMGST@PITTVMS  or  new-stfar asotffectst.edu "My ideas. Ajust caMINE!!haps -rnews 1043said 
wt!bc
Ifll
 doonot neebut aled, ie. Cevax.U!pannon
From: pannonof us      admocom (Joe PannonGMT
References: <48 ulture.magyar
Subject: Re: Antall'