Automatic control of solar street light

Discussion in 'The Projects Forum' started by Roadrunner, Feb 22, 2013.

  1. Roadrunner

    Thread Starter New Member

    Feb 14, 2013
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    0
    I want to design an LED street light operating on solar power. The maximum voltage and current output from the panel are around 16.4 V and 2.4 A. The light should get switched on or off automatically as per the ambient light conditions.
    For this purpose photo-sensors are available, but I want to use voltage sensors. When it gets dark , the output from solar panel becomes low. If I take 4 V as the threshold, the light should get ON when the panel output voltage drops below this, and vice versa.
    Can I use microcontrollers for this? But wouldn’t the current (2.4 A) be quite high for a microcontroller?

    Thank you :)
     
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    You don't need a microcontroller.

    Just a comparator or op amp, which in turn drives either a MOSFET (switches ground side of LED), or a relay (Switch either side of Light).

    Google search for "Solar cell dark detector relay" or "Solar cell dark detector MOSFET".

    You'll find many circuits, one may have parts you already have on hand.

    Are there any special requirements? Temperature Swings, vibration, humidity, battery monitoring/charging circuit, etc.?
     
  3. Roadrunner

    Thread Starter New Member

    Feb 14, 2013
    14
    0
    That helped a lot !! :)

    There aren't any special requirements, it is just needed for lighting up the perimeter of a certain area.
    But, what would a street light have to do with vibration (as you asked) ?
     
  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    I know some people who still have fun kicking streetlights and knocking out the light for a few minutes. They are engaging the "wreck detector" which kills the power, and the lights need to be off for 5 minutes prior to a restart.

    Didn't know if you had deviants in your area or not. :D
     
  5. Roadrunner

    Thread Starter New Member

    Feb 14, 2013
    14
    0
    That is interesting and disturbing :/
    I don't think such incidents will happen in my area :)
     
  6. Roadrunner

    Thread Starter New Member

    Feb 14, 2013
    14
    0
    Would a current sensor be much more precise and sensitive in this context?

    I think current change will be more rapid , as the first thing that happens in a photocell when the light intensity increases or decreases is a change in the electron flow.
     
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