Path: newsstand.cit.cornell.edu!ub!dsinc!newsfeed.pitt.edu!gatech!newsfeed.internetmci.com!news.msfc.nasa.gov!pendragon!ames!newsfeed.gsfc.nasa.gov!rs710.gsfc.nasa.gov!ebc714
From: ebc714@rs710.gsfc.nasa.gov (Edward Cheung)
Newsgroups: comp.home.automation
Subject: Re: TV & VCR IR Remote Remote ??
Date: 1 Mar 1996 13:29:04 GMT
Organization: NASA Goddard Space Flight Center -- Greenbelt, Maryland USA
Lines: 36
Message-ID: <4h6u30$g1i@post.gsfc.nasa.gov>
References: <4h5aqn$t05@dub-news-svc-6.compuserve.com>
NNTP-Posting-Host: rs710.gsfc.nasa.gov

>From: 100550.114@compuserve.com (Paul Kelly)
>Does anybody know of a published design (circuit diagram, PCB,
>components list, etc) for an infra-red remote control remoter?

Since I am bad at ASCII schematics, I will describe a circuit.  It should
be easy to build if you have any electronics experience.

Radio Shack and Digi-Key sell IR receiver 'cubes' that envelope detect the
IR stream.  Their output is an open collector transistor.  Place this
in the bedroom along with a pullup resistor on the output.  Wire this
(preferably shielded) to the room with the A/V equipment where you have a 
40Khz LED flasher.  You can use a 555, with the pin 4 used as the gate control.
You will also then need an inverter between the IR cube and the 555.  One old
trick is to use a 555 as an inverter, and then use the dual 556 package.
Benefits of the 555 in this case include - high output drive current, cheap,
commonly used.

When there is an IR pulse, the output of the cube goes low, and the output
of the inverter goes high, and the LED will start flashing.

Multiple cubes can be connected together so that you can combine the output
of several rooms since the outputs are open collector.

All this presumes that you are in the US.  I do not know about buying parts
in the UK (your location not evident from your note).

+---------------------------------------------------------------------------+
|          Edward Cheung, Ph.D.         |  The opinions expressed herein    |
|    NASA Goddard Space Flight Center   |    do not necessarily reflect     |
|           Mail Code  J&T/442          |       those of my employers'      |
|          Greenbelt, MD 20771          |                                   |
|   301-286-1269(office) 286-1717(fax)  |  My next book:                    |
| Internet: edward.cheung@gsfc.nasa.gov | Statistics, Demos and Other Lies  |
+---------------------------------------------------------------------------+


Newsgroups: comp.home.automation
Path: newsstand.cit.cornell.edu!ub!csn!news-1.csn.net!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!newsfeed.internetmci.com!in1.uu.net!fi.gs.com!psd.gs.com!weissj
From: weissj@psd.gs.com (Jeffrey Weiss)
Subject: Re: Infra Red Extender - Home-built? [Schematic Included]
In-Reply-To: griffd@techtiks.demon.co.uk's message of Thu, 29 Feb 1996 19:53:39 GMT
Message-ID: 
Lines: 181
Sender: news@fi.gs.com (Netnews Administrator)
Nntp-Posting-Host: cezanne.psd.gs.com
Organization: Risk Systems Development - Goldman, Sachs & Co.
References: <313603c2.345308854@news.demon.co.uk>
Date: Mon, 4 Mar 1996 18:45:33 GMT

[Following is a post I made to sci.electronics several years ago.  I think it
 does what you want.  A uuencoded GIF of the schematic follows the notes
 section. -jw]

Receiver Module:  I'm using the Sharp IR detector module (GP1U52X) because it
is simple, cheap, small, easily available (through your pals at Radio Shaft),
and outperforms any circuit I've been able to find and tweek.  It also looks a
lot like the receiver module I've seen in some real equipment.  It detects
pretty well at ranges up to about 15 feet or so with commercial remote
transmitters.  I've gotten up to 20 feet with fresh batteries.  The module
detects any signal that's travelling on a carrier of about 40KHz, which is
what's used by every consumer product I've seen.  The only disadvantage for
our application is that the module conveniently removes the carrier and
outputs the "real" signal.  Ergo, the 555 timer (I'm using a CMOS version
generically named 7555, and available everywhere).

Oscillator:  The 555 is set up as a simple oscillator (frequency of about
39.7KHz set by the 150K resistor and 120p cap).  The signal is applied to the
555's reset pin to act as a gate, resulting in the signal re-modulated on an
appropriate carrier at the output.

Emitter:  I've set the IR LED current pretty conservatively (using R(L) = 100
ohms), giving about 4 feet of range using a run-of-the-mill LED.  This works
fine, as the LED can be placed up close to the receiving equipment.  For
multiple emitters, you'll have to do a slight modification involving R(L).  If
you need really massive output, I'd recommend using 2 (or more) 1N6266 IR 
LED's in series.  You can run these guys at up to about an amp (yes, that's
1A) peak, and they just keep getting brighter and brighter.  I've run a pair
at about 600 ma. peak for about 12 feet or more of range.  You can get these
guys at DigiKey for a coupla-bucks each (and order some blue LED's while
you're at it).

Construction notes:  Nothing real special here.  I was able to get the whole
thing, plus a 5 volt regulator into a small (about 3x2x1) box (also from The
Shaft - but you can't beat their prices on small boxes, believe it or not)
with a jack for the LED-on-a-wire, and another for power in.  I used a cheap
9 volt 100-or-so milliamp wall transformer.  Make sure you ground the metal
case of the GP1U52X.  I mount the visible LED near the module.  This gives me
feedback as to what the module is receiving, and helps in aiming at long
distances.  I find that it helps to have the module sitting behind a front
panel peeking through a .25" hole.  This recesses the detector a little, and
keeps it from firing too much from background lighting.  This is only a nit,
as none of this noise would ever be interpreted by your equipment, but it
keeps the visible LED off when not in use.  I don't see why there should be
any serious limit on the length of the cable for the IR LED.  Treat it like a
40KHz TTL signal cable (like a fast serial computer link).  And don't forget
a few power supply bypass caps on the board.  I put one (.01 uF) near the 7555
and one (.1 or so) near the on-card regulator.

Below is the GIF schematic uuencoded.  Ask your local jock if you don't know
how to deal with it.  I'll also send a paper copy of the schematic to anyone
who sends a stamped self-addressed envelope to me at:
Jeffrey Weiss
808 Broadway
New York, NY  10003

Jeffrey.Weiss@gs.com
--
jw (weissj@psd.gs.com)

(The above mentioned GIF has been decoded, converted to PNG, and is shown below.) 

Path: newsstand.cit.cornell.edu!ub!csn!news-1.csn.net!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!gatech!news.mathworks.com!uunet!in1.uu.net!ausnews.austin.ibm.com!joel
From: joel@austin.ibm.com (Joel Davidson)
Newsgroups: comp.home.automation
Subject: Re: Infra Red Extender - Home-built?
Date: 1 Mar 1996 23:37:44 GMT
Organization: IBM R/S 6000 Division
Lines: 118
Distribution: world
Message-ID: <4h81o8$1h0g@ausnews.austin.ibm.com>
References: <313603c2.345308854@news.demon.co.uk>
Reply-To: joel@austin.ibm.com
NNTP-Posting-Host: davidson.austin.ibm.com
Originator: joel@davidson.austin.ibm.com


In article <313603c2.345308854@news.demon.co.uk>, griffd@techtiks.demon.co.uk (David Griffiths) writes:
> Does anybody have any or know where I can get plans to build an
> Infra-red extender system?  I have plans for a transmitter and
> receiver, but unsure if the signal from the receiver needs amplifying
> over a distance.
> 
> Dave Griffiths
> griffd@techtiks.demon.co.uk
> 
Attached is a message that came from this newsgroup a while back. 
You could also check the follow web pages. 

ftp://tracker.vet.uga.edu/pub/asre/zaptest.zip
http://weber.u.washington.edu/~pfloyd/ee/circuits/PCIR/Welcome.html
http://www.armory.com/~spcecdt/remote/IRremote.html
http://www.armory.com/~spcecdt/ftpIndex.html

Joel

-----
Article: 2334 of comp.home.automation
Newsgroups: comp.home.automation
Path: awdprime.austin.ibm.com!portal.austin.ibm.com!geraldo.cc.utexas.edu!cs.utexas.edu!howland.reston.ans.net!gatech!rutgers!att-out!nntpa!ssbunews!not-for-mail
From: alt@ixstar27.ih.att.com (na5301700-Todesco)
Subject: IR Repeater Schematic
Message-ID: 
Sender: news@ssbunews.ih.att.com (Netnews Administration)
Nntp-Posting-Host: ixstar27.ih.att.com
Organization: AT&T
Distribution: na
Date: Tue, 18 Oct 1994 12:50:34 GMT
Lines: 77

Below is my IR Repeater schematic.  Delete everything above the
"begin 644" line, uudecode it, and then pkunzip it.  The file
may then be printed on any postscript printer.  Hope this works.
Art
-- 
_________________________________________________________________________
Joel Davidson                   The opinions expressed are mine and do
IBM R/S 6000 Division           not represent the position of IBM.
Austin, TX

(The above mentioned PostScript document has been unpacked and converted to the below PNG image. Click on the image to view a full size copy of the schematic.)