Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!ucsd!ames!hc!lll-winken!uunet!mcvax!ukc!strath-cs!al
From: al@cs.strath.ac.uk (Alan Lorimer)
Newsgroups: sci.electronics
Subject: Re: chase light schematics wanted
Message-ID: <1178@stracs.cs.strath.ac.uk>
Date: 29 Jul 88 08:35:21 GMT
References: <24055@bu-cs.BU.EDU> <7200002@silver>
Reply-To: al@cs.strath.ac.uk
Organization: Comp. Sci. Dept., Strathclyde Univ., Scotland.
Lines: 46

In article <7200002@silver> commgrp@silver.bacs.indiana.edu writes:
>
>
>
>>I'm looking for the schematics to a simple chase-light circuit, 
>>or anything else that might be neat to hook up to the 9 lamps in 
>>my 9-line ATTfone...
.
.

>II.  DUAL SEQUENTIAL FLASHER             [designed by Chuck Lane]
>
>555 drives two J-K flipflops in 7473 arranged in series as freq. 
>divider (Q output of one connected to C input of other, all J and 
>K inputs to Vcc).  Three lines (555 output, Q outputs of both 
>flipflops) go to A,B,C inputs of 74145 10-line decoder; input D 
>is grounded.             

How about CD40106 based 1 invertor clock driving the input of a CD4017
decade counter. The outputs of the decade counter go to leds ( connect
several leds in series to each channel if necessary - it doesn't cost
any more to run. Add a single 270ohm or so currenlt limiting resistor in
the common line of all the leds and away it goes.

Total cost is 2 chips, 2 resistors and 1 capacitor. Battery life in this
case is at least a week continuous, from a PP3 alkaline cell. I used
this circuit built into a tie for a "White Shirts and Fancy Ties Party"
driving a total of 16 leds ( 8 channels 2 leds/channel)
It has been borrowed by several friends and is frequently left on all
night - and it *Still* hasn't needed a new battery in over a year's
party going.

For installation in a telephone, this could be good, since a simple
power supply compising a diode, zener diode, resistor and capacitor will
make it work from the line's ringing volts. Some experimentation might
be necessary to stop the circuit holding the line on a hangup. The 4017
will handle up to 10 channels, so it should be ideal for your 9 light
telephone.


Alan.

-- 
____________________________________________________________________________
Alan G. Lorimer, Strathclyde University, 26 Richmond Street, Glasgow G1 1XH.
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