How big is the path of an IR emitter

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    Ir Path
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Discussion Overview

The discussion revolves around the characteristics of the infrared (IR) signal emitted by remote controls, specifically focusing on the size and shape of the signal path when a button is pressed. Participants explore the divergence angle of the emitted signal and its interaction with the environment.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • One participant questions the nature of the IR signal path, suggesting it may originate from a point source and form a cone shape.
  • Another participant notes that most IR LEDs emit light with a divergence angle of a few degrees.
  • A different participant observes that when viewed through a mobile phone camera, the IR signal appears to have a divergence angle of several tens of degrees.
  • It is mentioned that IR light reflects well off walls and furniture, which can contribute to triggering the receiver even when not in direct line of sight.
  • One participant shares a personal anecdote about using the mobile phone camera method to check the IR emitter while in bed, indicating practical applications of the discussed concepts.

Areas of Agreement / Disagreement

Participants express varying views on the divergence angle of the IR signal, with some suggesting a few degrees and others indicating it may be several tens of degrees. The discussion remains unresolved regarding the exact characteristics of the IR signal path.

Contextual Notes

There are limitations in the discussion regarding the specific measurements of divergence angles and the conditions under which the IR signal is effective, as well as the influence of environmental factors on signal reflection.

MartinJH
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This is a very silly question but anyway.

When using a remote for a TV or digital channel receiver, how big is the path/signal emitted from the remote when a button is pushed.
Will it come from a point, thee emitter, and form a cone shape until its picked up by the receiver.

its a dull question, I know. :)
 
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From what I found, most IR LEDs emit into a divergence angle of a few degrees.
 
If you look at it through your mobile phone camera, you'll see it flashing. (...Looking...) Hmm, I'd say it's more like few 10's of degrees. Also IR is reflected well by the walls and furniture, often this reflected light is sufficient to trigger the receiver.
 
Andy Resnick said:
From what I found, most IR LEDs emit into a divergence angle of a few degrees.

Thank you.

Delta Kilo said:
If you look at it through your mobile phone camera, you'll see it flashing. (...Looking...) Hmm, I'd say it's more like few 10's of degrees. Also IR is reflected well by the walls and furniture, often this reflected light is sufficient to trigger the receiver.

I always use that method when in bed or not in direct path to the TV :) lol.
 

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