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Does anyone know how I can do this?

  1. Aug 14, 2011 #1
    So I have an idea for a product, but I'm not sure how to go about doing it. I won't say exactly what the product is (no offense), but basically I would need a watch/sensor to activate a timer when passing by a pole.

    What would happen is a person would wear this watch (with sensor inside it), or some type of arm band with a sensor inside it, and as they passed this pole (which would also have a sensor on it), a timer would start. I'm guessing it would have to be a laser sensor as well (maybe that's the only type of sensor there is, I dont even know).

    Anyway, I'm sure the technology for this exists, I just need a little help in which direction to go.

    I really appreciate any advice. Thanks.
  2. jcsd
  3. Aug 14, 2011 #2


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    Gold Member

    Look up RFIDs. They're what you want I think.
  4. Aug 14, 2011 #3


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    Staff: Mentor

    Welcome to the PF.

    As Dave says, RFID is a common way to do this. The technique is used every weekend at triathlons and marathons to time all of the athletes. I did a Google Images search on Triathlon Timing Systems, and got lots of good hits:


  5. Aug 14, 2011 #4
    Ok great. Thanks for the help. One other question though. Do you know if the timer could start instantaneously when one sensor passed the other? I need it to be an accurate measurement so if it takes a tenth of a second to start even it won't work.

    Thanks again.
  6. Aug 15, 2011 #5


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    Staff: Mentor

    The timing systems for athletic events are quite accurate. The main variable is how close the chips have to pass near the sensors. You can probably get specs on the systems by following some of the links in the Google Images URL, or by doing your own refined Google search.
  7. Aug 15, 2011 #6
    Yeah that's exactly what it would be for, an athletic event. I didn't know they used RFID for that, but if so then that's perfect. Thanks again.
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