need an idea for a sensor to trigger a digital input upon impact with a hockey puck

Discussion in 'The Projects Forum' started by saint1000, Feb 3, 2013.

  1. saint1000

    Thread Starter New Member

    Jan 23, 2013
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    i have a project im working on, it will consist of 4 8" round targets in the 4 cornors of a hockey goal. when the targets are hit, i need a sensor for each target that will send a digital signal,(basicly send a 5v ref out) back teto my i/o board. the 8" targets are made out of 3/4" high impact plastic. they will be mounted to the goal with a gate closing sping like these.

    [​IMG]rget

    this should allow the target to take a hit and return to its position. i need a sensor that can mount to the back of the target, so it can not be hit directly by a hockey puck, but some of the kids are shooting 70 + mph. what type os sensor can i use?
     
  2. MrChips

    Moderator

    Oct 2, 2009
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    I think a piezo transducer or strain gauge should work, with proper amplification and signal conditioning.
     
  3. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    Coincidentally, I have been experimenting with a piezo transducer used as the trigger for a 555 one-shot. I agree with MrChips that a piezo would work. Are you going to wire the sensors to the control point or use RF?
     
  4. saint1000

    Thread Starter New Member

    Jan 23, 2013
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    i need 4 of them and each one will be wired to a usb controlled i/o relay board.
     
  5. saint1000

    Thread Starter New Member

    Jan 23, 2013
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    my main concern is false positives. if a shot hit the goal post next to were the target mounts i do not want it to read as a hit. how accurate are the piezo tranducers? can you adjust the sensitivity of them?
     
  6. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    I imagine the piezo element sandwiched between the back side of the target and a small backer plate, with some thin padding, such that it would take a direct hit to propel the target rearward, thus compressing the foam sufficiently to put pressure on the piezo. Of course, at this point, I'm just speculating.
     
  7. saint1000

    Thread Starter New Member

    Jan 23, 2013
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  8. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    I really don't know enough to have a valid opinion. It's apparently designed to be used with a microcontroller; the Arduino is mentioned by name. Do you have μC experience? The price is certainly reasonable.
     
  9. saint1000

    Thread Starter New Member

    Jan 23, 2013
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  10. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    I'd just do it simple and direct with a micro switch such as this:

    [​IMG]

    I'd expect the puck to come in hard and fast so moving the plate & switch isn't the issue, supporting the plate so it doesn't push the switch off it's mounting is.
     
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