I am making a Universal Remote Control for persons with physical handicaps. Many times, they cannot point remote control towards the receiver due to physical limitations. I have noticed that many of the commercial IR based remotes seem to work without line of sight.

My guess is that they send very strong signal and possibly have wider beam angle of IR LED so that they can achieve this. I notice that they seem to work from reflected beams if it is not in line of sight.

Can any one share some more information on this as to how to do this in a cost effective manner? For example, which IR LED to use and how much current to send through LED and so on.

Thanks,
- PR

Save yourself the headache and simply add RF. IR sucks, compared. Avoid having to point altogether and make it RF.

"Save yourself the headache and simply add RF. IR sucks, compared. Avoid having to point altogether and make it RF. "

Thanks. But in this case I do need to use IR since I am using standard devices with built in IR receiver.

The RF will still work. The remotes sends RF to a base unit and the Base has IR emitters plugged into it or an IR blaster that flashes all of the equipment.

An IR system will use an IR repeater which still needs the remote pointed at the IR receiver( usually located close to the TV/Display)  problems with IR repeater systems is if the remote is blocked while sending commands..the command is lost. If that command is in a macro usually something wont power on or off or the TV misses an input change and now the client/end user is confused and begins the button pressing in anger and leads to a late night call or weekend call

We have made RF based system already. We are looking at lower cost alternatives. I think I already understand what I need to do. Commercial systems seem to send much higher pulse current so that reflected IR signals also work. I am increasing the current from about 150 mA to 1000-1500 mA now to see if I get the similar effect that cheap commercial remote seem to get. Thanks anyway.

If you don't want to go the RF route, (IMO the best way to go) the best IR remote I have found over the years, is the Xantech URC-2. Very powerful. Don't have to point ''too much''. All hard buttons. Completely customizable. PC Programmable. Back lit. Macros. Old school remote, but reliable. Read the review on RC. You can get a cheap one on ebay, with a little patience.

I need to make my own remote as I would not be using buttons and would take input from some other source. I just wanted to duplicate the same kind of transmitter that "Xantech URC-2" may be using. I think we are now able to do this by sending much larger current than we had done earlier. Earlier we were sending about 150 mA and now it is close to 1.2 A. As I said I am making two different remotes. One with RF and other without. Cost with RF is higher.

haha ... well if you know better why bother asking?

Ensure you don't make it TOO strong. Some IR devices can be overloaded (ie. Scientific Atlanta cable boxes).

Most universal remotes have between 1 and 4 IR emitters. Sometimes there are a mix of narrow and wide focus ones. A couple remotes have actually put emitters on the front sides. Also, if you have a plastic shield over your emitters, ensure they are as close to the front and have a large enough field of vision so you don't suffer from "tunnel vision" which will reduce range.

Although the remotes pictured are a bit dated now, you might want to poke around here - you can see the Xantec URC-2, as well as the HTM MX-500 (another strong one). Some of the worst real-world performing remotes pictured there are the OFA URC-9900 and Jenson SC-595.

You can see a more current remote's emitters here. Its performance was well below average (scored 3.5 compared to an average performance of 7.0 and peak of 11.0).

When I made the original post, I did not know better! May be I am wiser now :-)

Thanks for detailed information. I had planned 4 IR emitters originally and even made a prototype based on that. However I saw many low cost commercial remote controls in the market that were working with single IR emitter and so in the new design we decided to use only one. With few trials, it seems to work well once we pulse in much higher current of about 1.2 A or so. We tested it side by side with a commercial remote control and they perform nearly same.

Are there any downsides to choosing RF over IR?

Can you be more details in your question as I do not understand in which context you are asking this.

Hmmm..... Are you using an IR LED that can sink that much current, long term?
If your IR LEDs burn out long before they should (every year or two), then I don't think your customers are going to be very happy with your remote.