Ir audio transmitter and receiver

Discussion in 'The Projects Forum' started by stupidguy123, Sep 25, 2011.

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  1. stupidguy123

    Thread Starter New Member

    Sep 25, 2011
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  2. Audioguru

    New Member

    Dec 20, 2007
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    I have seen that old circuit before on other websites. I don't think the transmitter works because its first transistor has no base bias current and the red LED shorts the audio signal.

    The first two transistors in the receiver are a preamp and the 3rd transistor is a class-A driver for the low impedance headphones.
     
  3. stupidguy123

    Thread Starter New Member

    Sep 25, 2011
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    yup, i know we should add a source to make a base current. but the second part still not work........do u know??
     
  4. Audioguru

    New Member

    Dec 20, 2007
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    The transmitter circuit is a total disaster.

    In addition to the first transistor missing its base bias current the red LED is shorting the audio signal so the second transistor in the transmitter does not modulate the current in the IR LEDs.

    The receiver circuit is also a total disaster.
    I forgot to mention that the receiver puts DC through the headphones which might cause them to burn out.

    The circuit comes from a website in India where almost all circuits do not work.
    http://www.electronicsforu.com/electronicsforu/lab/freecircuitslist.asp?id=26&title=Infrared Cordless Headphone
     
  5. ojaswi

    New Member

    Apr 14, 2015
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    can you explain the circuit in detail including how all the values are chosen
     
  6. bertus

    Administrator

    Apr 5, 2008
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    old thread, now dead.
    The topic starter can always ask a moderator to open the thread again.
     
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