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LED Street Lighting Power supply

Jason

Hello All,

As we know, LED is used moreand more on street lighting, in the future, LED will replace the traditional street lighting bulb. Many supplier have there own power supply solution for LED street lighting, such as NXP, ON, PI,TI, Fairchild and so on, some solution is isolated Fly-back and some is non-isolated high voltage Buck to drive LED bulb, some solution use PFC controller and some use Valley PFC circuit to increase power factor. The question is which solution is more popular for the LED street lighting? isolated or non-isolated,  PFC controller or Valley PFC circuit?

  • in reply to Jason
    Microchip’s reference design actually is a closed-loop voltage control. Since secondary and aux coil has a fixed ratio, feedback input is sample from AUX. there is a note on PSR http://www.fairchildsemi.com/an/AN/AN-6067.pdf
    image
  • in reply to Jorge_Garcia

    Hi Gorge,

     

    I thought it was a general flyback topology at the beginning, but in fact it is a single-stage Flyback which use PFC IC as its controller. They are similar but not same, you can see the capacitor C2 which is behind the bridge rectifier BD1, just 0.47uF, if it is a general flyback, C2's value must be over 68uF. We can see in the general flyback topology,the waveform on C2 is approximate DC but "m" type waveform in the single-stage Flyback topology. This is the ultimate differentia.

     

    Ti's solution is very good which use TPS92210, but apply the sample difficultly. I will use TI's reference design as my design resource

     

    Jason

  • in reply to SmartEnergy

    Hi Hausa Lee,

    Thanks for you attention.

    I have seen many primary feedback applications such as cell phone charger, Li-on charger. But it always low power and low precision requirement. I don't konw if primary feedback suit to my project, I have set three type of output 350mA, 700mA and 1050mA, which have only +/-10% tolerance.

     

    Jason

  • in reply to Jason

    Dear All,

    I 've accomplish my PCB design, it is single side layout and both side component placement.

    image

    Attachments:
    imageLED2.pdf
    imageLED1.pdf
    imageLED.pdf
  • in reply to Jason

    I've received my PCB from the PCB maker and follow picture is it, very beautiful I think.

    image

  • Checkout the TI LED Cookbook....  www.ti.com/led

     

    Selection Guides

    • LED Reference Design Cookbook (Rev. A) (PDF 6.52 MB)  17985 views
      05 May 2010                                                                                                                                                                                                                                                                  
    • Power Management Guide 2010 (Rev. J) (PDF 7.71 MB)  32885 views
      25 Nov 2009                                                                                                                                                                                                                                                                  
    • LED Drivers Catalog (PDF 1.03 MB)                                           2444 views
      21 Aug 2007

  • Hello Jason,

    very nice design. In fact, a single stage PFC flyback topology had been presented at Fairchild's power seminar tour this year, and the presentatino is available on our website, and you can find some reference designs at http://www.fairchildsemi.com/applications/diagrams/lighting.html (e.g. RD-009 which is based on the FL6961). It appears that valley-fill is not so much of an issue since with a full bridge rectifier the ripple is 100Hz, and you can adjust with the size of the cap to reduce it (some very few people are capable of seeing it, so it seems).

     

    If you need any further support to get your design going, please feel free to get in touch!

    alfred