TSOP4838 (IR demodulator) extremely sensitive

Discussion in 'General Electronics Chat' started by Lem0nHead, Oct 29, 2010.

  1. Lem0nHead

    Thread Starter New Member

    May 4, 2009
    4
    0
    hello
    I'm using TSOP4838 to detect an IR LED that I'm using for a proximity sensor

    the IR LED is already modulated (by a PIC) to 38 kHz (1ms oscillating, 1ms LOW)

    the problem I'm having is that this detector is extremely sensitive
    I tried with my remote control, even if I put a couple of paper in front of the sensor and activate the remote control, it detects it ... which is great for long distance communication, but terrible for a proximity sensor for 2~3inches

    if I plug a LED on the same board, I never get to make "not-detect"

    any hints?
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,646
    2,344
    Hello,

    How are the led and tsop situated?
    Can you make a drawing?

    Bertus
     
  3. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
    5,676
    899
    1) If you plug into the same board, be sure the power supply has adequate decoupling capacitors -- at the supply and at each device.
    2) Paper is or can be almost transparent to IR. Use black vinyl electrical tape. An aluminum can (like a cigar tube) also blocks IR.

    John
     
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