Angle sensor for large Solar Panel tracker

Discussion in 'The Projects Forum' started by TexasTony, Apr 23, 2013.

  1. TexasTony

    Thread Starter Active Member

    Jul 15, 2010
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    Hi,

    I'm onto a new project, putting up a few tracking solar 'trees' to power the house. I've already welded together the arrays (10 ft x 10 ft each) to hold the solar panels so I'm well into this. It weighs nearly 1000 lbs (array + panels) and I made a heavy duty hinge to support it.

    What I am wanting to do is have a way to sense what rotational angle is the array sitting at. The reason is in case of strong winds, I want to rotate the array to horizontal for minimal stress. Note that my hinge is a beast of a hinge, so a rotation sensor connected at the hinge is not a good idea.

    I'm finding gyroscopes, but I don't really care about the rotational speed or acceleration (in fact they will only introduce error). I just want to know what tilt angle is it at. A little IC would be great. Any suggestions?
    Thanks
    Tony
     
  2. nickelflipper

    Active Member

    Jun 2, 2010
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  3. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Another acceloration-tilt sensor: Parallex MX2125, may still be available from RS. Puts out a PWM signal.
     
  4. TexasTony

    Thread Starter Active Member

    Jul 15, 2010
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    Thanks guys. That sent me in the right direction. The first part listed has actually been discontinued. But I found this one:
    http://cache.freescale.com/files/sensors/doc/data_sheet/MMA6331L.pdf

    It's called an accelerometer. But I think it will measure the tilt, and it's 2-dimension measurements. It does say to keep the microcontroller close. So I'll probably end up with 2 uC's, no big deal there. One up on my tilting array, and one down low where I can reach it.

    Thanks again
    Tony
     
  5. John P

    AAC Fanatic!

    Oct 14, 2008
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    You could always use old technology, a potentiometer operated off the mechanical parts. It doesn't have to be connected directly to the hinge--there could be a little linkage that operates it.
     
  6. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    exactly what I was going to recommend.. its simple and just plain works.
    string pots,etc...
     
  7. sparemma

    New Member

    Feb 11, 2015
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  8. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Intresting, but it does not apply to this post.
     
  9. wayneh

    Expert

    Sep 9, 2010
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    Won't this require just two positions; horizontal and tilted up for normal operation? I don't understand why you'd need to know any angle in between. You just need limit switches.
     
  10. MikeML

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    Oct 2, 2009
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  11. crutschow

    Expert

    Mar 14, 2008
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    I agree with wayneth.
    Why not just use limit switches?
     
  12. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    light sensor circuit with the sensors on east and west. when one is shaded tilt drives until both sensors are equally illiuminated.
    anometer input would place panels in 'storm' parking mode. use an integrator with a long time constant to get high wind signal and ignore short gusts.
     
  13. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Perhaps the OP needs to change the angle of the array with the time of year. Limit switches would be good for overrun, but a pot would be cheap and easy for angle.

    Ken
     
  14. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    perhaps you all need to realize this is a post from 2013 until that spammer bumped it back to life :p:)
     
  15. wayneh

    Expert

    Sep 9, 2010
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    Aaarrrgh!
     
  16. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    2013, 2014. details details details.

    the thread was obviously incomplete! :)
     
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