ADICON Support Forum Applied Digital, Inc.
Page 1 of 2 12>
Topic Options
#15273 - 03/02/06 10:16 AM Build an infrared (IR) blaster
Guy Lavoie Administrator Offline
Beyond All Hope
*****

Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
The IR output on a Ocelot/Leopard is designed to be used with stick-on emitters such as the ones made by Xantech. These need to be stuck right over the TV's (or whatever device you're controlling) IR receiver window. In many installations, you might want to have a high power IR transmitter (often called a "blaster") located somewhere in front of the device(s) that you want to control so that the commands can be sent just as if you were using a handheld remote from a distance.

The Ocelot or Leopard is driving the infrared (IR) emitter in a low power fashion using a pullup circuit through a current limiting resistor to drive the IR LED directly. All you need is a small amplifier circuit to drive a regular IR LED at high power in order to send ("blast") IR across a room. IR LEDs ( and any LED for that matter ) can be driven at relatively high currents if the duty cycle is very short. The IR LED I used here is rated for about 20 mA if ON continuously, but can be driven with about 1.2 A (yes, that's amps )when pulsed for microseconds at a time as is done in remote control protocols.

Examine the schematic diagram below. The IR LED I used is a Radio Shack cat # 276-143C, but pretty well any IR LED should do. One important thing to note: Use a seperate 12V dc power supply for the circuit, do not try to use the same power supply as the Ocelot or Leopard! This is because the controller's power input goes through a bridge rectifier internally, so you do not have the same common ground on the external IR jack. Use an isolated wall transformer (wall wart) with a 12v dc output. The 2N3904 transistor can probably be substituted by any general purpose NPN switching transistor, like a 2N2222. Another advantage with this circuit is that you can drive several IR LEDs simultaneously by replicating the circuit for additional LEDs. I have two IR LEDs in two rooms (I first verified that the IR codes for one TV were ignored by the other one; it helps if both TVs are of different brands). If you make more than one circuit, simply wire them to the same mini phone plug that goes to the Ocelot. The 12V power supply is shared by all circuits.





Note: you might not be able to find 15 ohm resistors at places like Radio Shack. In that case, you can create and equivalent circuit using more commonly available 10 ohm resistors, as shown in the diagram.

Top
#15274 - 04/09/06 07:01 PM Re: Build an infrared (IR) blaster [Re: Guy Lavoie]
Barryfive Offline
junior


Registered: 02/01/03
Posts: 44
Loc: Arizona
Wouldn't it be as just as easy to use an amplified block such as Niles or Xantech make and amplify the signal? You could then use multiple IR emitters.
Top
#15275 - 04/09/06 07:05 PM Re: Build an infrared (IR) blaster [Re: Barryfive]
Guy Lavoie Administrator Offline
Beyond All Hope
*****

Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
For sure, there are many solutions to IR signal distribution. If one of those connecting blocks supports a ready-made blaster too, then you can go that route. Most connecting blocks are to power stick-on emitters, which I didn't want to bother with.

This version is mostly for do-it-yourselfers who want to do it as a project.
_________________________
"If you don't know what you're doing, do it neatly..."

Top
#15276 - 04/25/06 07:08 PM Re: Build an infrared (IR) blaster [Re: Guy Lavoie]
Gemini Offline
newbie


Registered: 02/06/04
Posts: 19
Loc: Tennessee, USA
Guy, I built one of these a while back, but instead of using a power supply, I put a 9v battery in a small box with the blaster. It worked fine, but it got put on the back burner.
Question, any idea how long a 9v battery would power it in a "rest" mode, and maybe how long with moderate use?

Top
#15277 - 04/25/06 07:51 PM Re: Build an infrared (IR) blaster [Re: Gemini]
Guy Lavoie Administrator Offline
Beyond All Hope
*****

Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
I have no idea really. If there is very little leakage when the circuit is off, then it could last quite a while (similar to a battery powered remote) but you would need to try it to be sure.
_________________________
"If you don't know what you're doing, do it neatly..."

Top
#15278 - 05/19/06 05:39 AM Re: Build an infrared (IR) blaster [Re: Guy Lavoie]
Matz Hedman_dup1 Offline
newbie


Registered: 05/10/03
Posts: 8
Loc: Stockholm
Gemini
I have built the blaster according to Guy's layout powering it with a 9V battery. It has been running on the same battery for 3 years now and still alive and kicking.

Top
#15279 - 05/19/06 03:38 PM Re: Build an infrared (IR) blaster [Re: Matz Hedman_dup1]
Gemini Offline
newbie


Registered: 02/06/04
Posts: 19
Loc: Tennessee, USA
Thanks, that is what I was hoping to hear. I guess I'll blow the dust off of it and put it to use. Thanks.
Top
#15280 - 01/02/07 06:02 PM Re: Build an infrared (IR) blaster [Re: Gemini]
Todd R. Offline
active contributor


Registered: 05/27/03
Posts: 178
Loc: CA
Guy,

Could I use this circuit for a Xantech Hidden Link receiver output, which is 12vdc?

I assume you could tap off the output, which currently goes to a Xantech IR hub, and drive this blaster as well.

I need to turn a corner and blast a Russound A-Bus keypad that has an IR receiver!

Thanks
_________________________
Todd Reed

Top
#15281 - 01/02/07 06:10 PM Re: Build an infrared (IR) blaster [Re: Todd R.]
Guy Lavoie Administrator Offline
Beyond All Hope
*****

Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
Since the Xantech IR hubs have a positive going signal, it should work. The only change I'd suggest might be to replace the 2.2k resistor at the input with a 4.7k one since the input is now a 12v signal.
_________________________
"If you don't know what you're doing, do it neatly..."

Top
#15282 - 03/18/07 07:21 PM Re: Build an infrared (IR) blaster [Re: Guy Lavoie]
sash18 Offline
journeyman


Registered: 08/31/05
Posts: 61
Loc: Melbourne
Ok, well I tried to biuld one of these over the weekend and it didnt work. I used parts from Jaycar (Aust. Radio Shack equivilent).

I'm thinking I might have the resistors around the wrong way. Can you describe exactly which way these need to go (i.e. the coloured rings on the resistor in relation to which way the line is headed - the phone plug-transistor & IR LED). Sorry to be a pain, but I'm no electronics genious but can use a solderin iron effectively enough.

Also, I have a Marmitek IR repeater pyramid thingies that can take IR from one point and transfer it to another room via RF and then back to IR again.

My question here is 'Will this IR blaster be more effetive than the device I currently have?' Reason I ask is because I have the LEO 2 connected and the little IR emitter mouse thingy pointing directly at the pyramid and its not so good with IR, like the LEO 2 makes the IR happen and the pyramid works sometimes and not others. I want a better solution so I'm hoping this thing is powerful enough to be more consistent.

Cheer's
Sash

Top
#15283 - 03/18/07 07:45 PM Re: Build an infrared (IR) blaster [Re: sash18]
Guy Lavoie Administrator Offline
Beyond All Hope
*****

Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
Resistors don't have a polarity so they will work either way. The other parts are more important to get correctly however. The best thing would be for you to post some close up pictures of your circuit.

The IR blaster circuit does pretty well the same as the Powermids as far as blasing IR. The Powermids add the handy wireless link.

For the Powermid to work right, you need to put the IR mini emitter exactly over the right spot in the Powermid. Other forum members who have done this should be able to tell you exactly where.
_________________________
"If you don't know what you're doing, do it neatly..."

Top
#15284 - 03/18/07 08:04 PM Re: Build an infrared (IR) blaster [Re: Guy Lavoie]
sash18 Offline
journeyman


Registered: 08/31/05
Posts: 61
Loc: Melbourne
I have the emitter in that little section of the powermid. It does work through the LEO 2, but not as consistently as say if you were to point the remote at the powermid and push the button. Does this sound like an IR learning issue or something to do with the set-up? Ideally, the IR blaster would be better as it cuts out the RF bit and blasts it directly. Plus its easier to hide than the powermid. I'll post some pictures when I get home (be warned though, its pretty dodgy looking at the moment....lol).

One more question though, Point B on the diagram is connected to the middle prong coming out of the transistor right? If not, then I've got it wrong. I only ask becasue it looks a little like it may be the end prong and not the middle.

Cheer's
Sash

Top
#15285 - 03/19/07 07:42 AM Re: Build an infrared (IR) blaster [Re: sash18]
Guy Lavoie Administrator Offline
Beyond All Hope
*****

Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
Yes, point B is the middle pin.
_________________________
"If you don't know what you're doing, do it neatly..."

Top
#15286 - 03/19/07 08:57 AM Re: Build an infrared (IR) blaster [Re: Guy Lavoie]
Dowser Offline
journeyman


Registered: 12/04/06
Posts: 73
Loc: Sweden
Would it be possible to have multiple parallel IR-diodes without modifying that design?
Top
#15287 - 03/19/07 09:27 AM Re: Build an infrared (IR) blaster [Re: Dowser]
Guy Lavoie Administrator Offline
Beyond All Hope
*****

Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
I think that some people have done that with 2, maybe 3 diodes. If the goal is to get more signal strength, you might want to use 2 or 3 diodes and reduce the 15 ohm resistor to 8 or 10 ohms. It is best to get identical IR LEDs if you want to try this.
_________________________
"If you don't know what you're doing, do it neatly..."

Top
#15288 - 03/20/07 04:26 AM Re: Build an infrared (IR) blaster [Re: Guy Lavoie]
sash18 Offline
journeyman


Registered: 08/31/05
Posts: 61
Loc: Melbourne
Ok, its still not working. I have everything connected like your diagram and its a no go. This is quite a shame as I would rather use this than the powermid thingy's I'm currently using. This will be much easier to hide across the room than a pyramid looking thing. I've attached photo's. Now please dont laugh at the stupid way I did it. I didnt have a PCB so I just joined everything as required. I'm spewing it doesnt work.

Picture; (Sorry they came out blurry - phone camera)













Cheer's
Sash

Top
#15289 - 03/20/07 07:52 AM Re: Build an infrared (IR) blaster [Re: sash18]
Guy Lavoie Administrator Offline
Beyond All Hope
*****

Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
Those pictures are just too hard to figure out. I can't really what connects to what with any certainty. If you could borrow a digital camera and also get a picture of the whole thing it would help. Even better is if you know someone who does electronics as a hobby that could take a look at it.
_________________________
"If you don't know what you're doing, do it neatly..."

Top
#15290 - 03/20/07 02:38 PM Re: Build an infrared (IR) blaster [Re: Guy Lavoie]
sash18 Offline
journeyman


Registered: 08/31/05
Posts: 61
Loc: Melbourne
Ok, I'll use the digital camera tonight and take some better pictures. i dont have anyone that is an electronics guru so I'll have to do in this case....

Cheer's
Sash

Top
#15291 - 03/24/07 05:13 PM Re: Build an infrared (IR) blaster [Re: sash18]
sash18 Offline
journeyman


Registered: 08/31/05
Posts: 61
Loc: Melbourne
Not sure where it went wrong, but this thing started to work on its own without my help. It actually work quite well when its pointed in the right direction of course.

It certainly beats the alternative of using the powermids and stick on emitter. This is much easier to conceal and you can run the IR LED line pretty fat, I've put 2.5 meters on mine and it seems to work fine.

Thanks for this, it was pretty easy to make. Oh yeah, I'm running it on a 9V battery, I'll tell you how long it lasts.

Cheer's
Sash

Top
#15292 - 03/30/07 12:07 AM Re: Build an infrared (IR) blaster [Re: sash18]
sash18 Offline
journeyman


Registered: 08/31/05
Posts: 61
Loc: Melbourne
Quote:

I think that some people have done that with 2, maybe 3 diodes. If the goal is to get more signal strength, you might want to use 2 or 3 diodes and reduce the 15 ohm resistor to 8 or 10 ohms. It is best to get identical IR LEDs if you want to try this.




I'd actually like to try this to increase reliability and point them at the entertainment centre from across the room at a few different angles (3 - Centre, Left and Right). Guy, do you think you could modify your above pic to show how you would do this in parallel? Even if you just roughly pencil in where you would splice the wires into.

Cheer's
Sash

Top
Page 1 of 2 12>


Moderator:  Dan Smith, Monte G, ADI Tech Support, Guy Lavoie 
Hop to:
Who's Online
0 registered and 46 anonymous users online.
Recent Posts
Shout Box

Newest Members
brigiel, vevevie, zhutree, 416, saiqul
3003 Registered Users
Forum Stats
3003 Members
19 Forums
3998 Topics
23424 Posts

Max Online: 132 @ 11/13/16 10:07 AM
April
Su M Tu W Th F Sa
1
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30