Question about IR Sensor

Discussion in 'The Projects Forum' started by MrYu, Sep 10, 2012.

  1. MrYu

    Thread Starter Member

    Sep 26, 2011
    42
    0
    how to know if an IR sensor is TX or Rx?
    they are the same color(white). is there any way how to test it?
    or anything of the two can be use Tx and Rx? tnx..
     
  2. wayneh

    Expert

    Sep 9, 2010
    12,154
    3,061
    Can you show us a picture? Does the device have leads of unequal length?
     
  3. MrYu

    Thread Starter Member

    Sep 26, 2011
    42
    0
    yeah the pins are unequal length
    usually i found IR sensors with different colors which it indicates where Tx and Rx
    but this one is different

    [​IMG]
     
  4. Markd77

    Senior Member

    Sep 7, 2009
    2,803
    594
    Digital cameras can see infrared, so get a 3V battery, a 470 ohm resistor and try them both (also swapping pins) while looking at it on the screen of a camera. With low voltage and resistor I think it's safe for both components.
    A badly lit room helps.
     
  5. wayneh

    Expert

    Sep 9, 2010
    12,154
    3,061
    Those are almost certainly IR LEDs and I agree that you should test them as recommended. I think I'd try a voltage a bit over 3V though, to be sure you overcome Vf. 3 AA cells should be fine, using the resistor of course. Cellphone cameras will usually show you a lit LED.
     
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