Help with a laser trip wire with a motor attached.

Discussion in 'The Projects Forum' started by SiLK, Oct 9, 2008.

  1. SiLK

    Thread Starter New Member

    Oct 9, 2008
    7
    0
    Objective:
    To build a device that has an IR laser that when broken would activate a motor. The motor would be used to either pull the pin out of a Airsoft/Paintball grenade or strike it.

    The Unit:
    Would be attatched to a metal frame that would hold the grenade. The frame would be forced into the ground. The IR laser would simpally need to be broken and instantly activate the motor quickly.

    Thank you for your help.
    SiLK
     
  2. scubasteve_911

    Senior Member

    Dec 27, 2007
    1,202
    1
    Your description is vague. How is the IR beam going to be broken?

    If it is emitting from the box, then, it must be either reflected back to a sensor in the box or an external sensor must be used. I'm assuming you want it self-contained. If you're putting it on the ground, then you don't need a infrared laser.. You just just use infrared LEDs with a shrouded sensor to create a small field of view. You should modulate the signal so that light cannot false trigger.

    Steve
     
  3. SiLK

    Thread Starter New Member

    Oct 9, 2008
    7
    0
    Thank you for the reply.
    The beam will be broken by feet hopefully. I only said IR because its in a very dimly lite building and I did not want anyone to see the beam. I would like it all self contained if at all possiable. I would mount it just off the floor.
     
  4. scubasteve_911

    Senior Member

    Dec 27, 2007
    1,202
    1
    Okay, that makes more sense.

    For the simplest circuit, I would use this detector

    http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=475-1080-ND

    with this emitter

    http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=751-1208-ND

    Hook them up like

    http://home.cogeco.ca/~rpaisley4/PhotoDetectors.html
    under Basic Infrared Detector

    instead having the output of the opamp connected to (first circuit)

    http://www.sampson-jeff.com/tcrobowar/motor1/ver1.htm

    the mosfet should be a logic level or low-gate voltage type

    These are your basic guidelines

    Steve
     
  5. SiLK

    Thread Starter New Member

    Oct 9, 2008
    7
    0
    Thank you very much! I will post up how i get on.
     
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