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What is the correct way to wire a reflective object sensor — Parallax Forums

What is the correct way to wire a reflective object sensor

DunnerDunner Posts: 6
edited 2007-12-07 01:50 in BASIC Stamp
I am using a fairchild QRB1113 reflective object sensor. What is the proper way to wire it up

Comments

  • steve_bsteve_b Posts: 1,563
    edited 2007-12-03 14:58
    It's basically an opto-transistor.

    The LED reflects off of an object in to the transistor. The Transistor is turned ON and it conducts.

    The datasheet says the LED can take 50mA. With a Vcc of 5volts, you'll need a resistor equal to 5/50mA=100ohms minimum...I'd go for 120ohm resistor.
    Put the resistor between Vcc and the Anode. Then connect the Cathode to ground (hope I didn't get that backwards....).
    On the other end, you tie pin 4 (the collector) to a 1kohm resistor to Vcc. Then tie pin 3 (the emitter) to ground.
    connect your stamp to pin4 (between pin4 and the resistor) and whenever you have an object reflecting the light, you'll see a low on your stamp.

    Hope I got that right....

    cheers

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    <FONT>Steve



    What's the best thing to do in a lightning storm? "take a one iron out the bag and hold it straight up above your head, even God cant hit a one iron!"
    Lee Travino after the second time being hit by lightning!
  • DunnerDunner Posts: 6
    edited 2007-12-07 01:50
    Thanks steve you got it right
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