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solar power supply + backup power

Discussion in 'Renewable Energy' started by mabauti, Feb 13, 2008.

  1. mabauti

    mabauti Member

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    Yep, it's me again >_> , taking advantage of this great forum


    Anyway...

    I'm looking for a simple circuit about solar power supply with a backup power for nightly operation.

    The circuit I have consumes 20mA @ 5V (it is a clock + thermometer )




    Links and ideas are welcomed :)
     

    Attached Files:

  2. Krumlink

    Krumlink New Member

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    The CLock/Thermometer looks really cool!

    For a House supply oops (EDIT)
    As for Solar power back up, I would get high wattage solar panels and charge up a battery bank (think car batteries) and run a 120VAC inverter on it. Not very descripitve, but should point you in the direct direction.

    FOR YOUR CIRCUIT
    Seeing that it only draws 20ma at 5V, lets make it safe that it could for what ever reason start to want 50ma. I would get a 6W solar panel (12V 500ma) and run that into a 5V regulator. That should work great, and for night time put a 9.6V battery or whatever voltage would suit it and attach that across the input voltage (12V solar panel) and ground it electrically to the solar panel. Make it a NiCd or NiMH. This is just a vague suggestion, I would wait for some of the other pros to state their opinion too.

    Good Luck :)
     
  3. Kryten

    Kryten New Member

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    i would def go for batteries meant for use with solar panels, cos car batteries are ment to have large amount of power drawn from them and are not so good for long "light" discharge
     
  4. dave

    Dave New Member

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  5. Hero999

    Hero999 Banned

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    Six NiMH cells powering a LM2936-5.0 will do.

    You can eailly trickle charge the batteries at C/10 using a simple series resistor and schottky diode, to prevent them from discharging back into the solar cells.
     
  6. mabauti

    mabauti Member

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    Any schematic 999? >_>
     
  7. Hero999

    Hero999 Banned

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  8. mabauti

    mabauti Member

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    Thank you for the info Hero999 :)
     
  9. Kryten

    Kryten New Member

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    ooooppsss I guess i missed about the battery sizing all together :(
     
  10. srmd

    srmd New Member

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    Thank you for the information
     
  11. Super_voip

    Super_voip New Member

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    It looks like the LEDs consume most of the power. Is it feasible to turn them off, or reduce the power to them?
     

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