ir detection

Can reliability of IR or RF signals be influenced by time of day? I have an IR transmitter attached to my PC. It sends a signal to an extender, which converts it,
sends it to an RF convertor in another room, and the convertor then sends the IR signal to the TV set. Since I am just testing now, its just a simple on/off command.
This morning, I was able to put the last convertor almost 10 feet away from the TV set and it worked fine. This evening, it has to be within four feet to work.
I am using the MyExtender control from MyTv. I am open to other suggestions.
Thanks in advance for any responses.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Hi Al,
could it be that e.g. the ambient light on the IR receiver changes depending on the time of day? Depending on the design of the IR receiver, this could change the sensitivity. In a similar way, there might be equipment that is switched on only at certain times during the day, e.g. fluorescent lights, microwave ovens, etc. Such equipment might interfere with the RF transmission, depending on frequency, distance, etc.
I'd suggest trying to eliminate influences one at a time, e.g. first finding out whether it is RF or IR that is affected, then eliminating possible interferers/fixing ambient lighting, etc. Good luck & please let us know what came out!
Peter
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Most IR products use modulated light, I think at 38khz standard. So they should be resistant to interference. I know nothing about RF transmission, but if the last convertor needs to be moved closer, then its probably a problem on the IR end. I'm not familiar with the product you mention, but is it battery operated? IR LEDS consume a lot of power and could drain batteries real quickly.
--
|\/| /| |2 |<
mehaase(at)sas(dot)upenn(dot)edu
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

have
set.
from
Modulated IR signals are resistant to ambient light within reasonable limits. Sunlight can block IR receivers. Try closing the curtains. Is it aimed directly at the receiver? IR is a line-of-sight transmission, so both the transmitter as the receiver should be able to "see" each other. A powerfull remote control can under some conditions reach a receiver indirectly (by reflection) but this is very unreliable. Otherwise replace the batteries. The range of a remote control depends mostly on the health of the batteries.
--Patrik
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

from
Some years back while on the team to build the greatest and latest bot we discovered our biggest problem was in sunlight coming into the playground and interrupting the IR signals. We solved the problem, temporarily, by using blinds and curtains. Maybe there are better solutions today. After all, my experience goes back more than 6 years.
Wayne www.pueblaprotocol.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I guess IR signals haven't improved much since your experience. Looks like I am having EXACTLY the same problem. I just repeated the experience of having the IR convertor/transmitter more than 10 feet away, but this time I made sure a nearby lamp was off and it was dark around the transmitter AND receiver. Success!
Thanks to all who responded. My experiments are back on track, thanks to you, plus I know a little more about IR than when I started.

have
set.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
: Can reliability of IR or RF signals be influenced by time of day? I have : an IR transmitter : attached to my PC. It sends a signal to an extender, which converts it, : sends it to an RF convertor : in another room, and the convertor then sends the IR signal to the TV set. : Since I am just testing now, its just a simple on/off command.
Absolutely. While the IR signal is modulated to reduce interference from ambient light, remember that the Sun transmits on all frequencies and modulations randomly. This means that your effective range of any IR transmitter will be heavily influenced by ambient solar radiation. You'll get lots better range at night than when you are getting solar rays blasting in the window.
DLC
: This morning, I was able to put the last convertor almost 10 feet away from : the TV : set and it worked fine. This evening, it has to be within four feet to : work.
: I am using the MyExtender control from MyTv. I am open to other : suggestions.
: Thanks in advance for any responses.
--
============================================================================
* Dennis Clark snipped-for-privacy@frii.com www.techtoystoday.com *
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.