Activate LED with IR phototransistor

Discussion in 'The Projects Forum' started by kja00, Nov 5, 2009.

  1. kja00

    Thread Starter New Member

    Oct 14, 2009
    10
    0
    Hello

    How can i make simple circuit with a infrared phototransistor and a LED, so the LED lights up when a infrared source like a remote control is pointed at it? The source should be a 9V battery?

    I guess that this is quite simple, but i am new to electronics and try to get small projects to work and learn from them.
     
  2. hobbyist

    Distinguished Member

    Aug 10, 2008
    764
    56
    See if this will work for starters.

    infra=red det..jpg
     
  3. kja00

    Thread Starter New Member

    Oct 14, 2009
    10
    0
    It's working perfect. Thank you.

    I did not have any 470 ohm resistor so i mounted 220 ohm and 330 ohm in serial. Can i remove the 220 one?, and what will the difference be if any?
     
  4. hobbyist

    Distinguished Member

    Aug 10, 2008
    764
    56
    It might be best to keep both resistors, so as to not overdrive the LED with too much current.

    Probably the smallest single resistor would be around 360 ohms that puts close to 20mA. through the LED, which is about max.
     
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