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Thread: design considerations

  1. #1

    Default design considerations

    I have been playing around with LEDs and japanese lanterns and have made up one using an lm317 regulating at 4.5V and switching 5 arrays of 3 5mm LEDs each randomly randomly with a microchip with we use in our family room a a nightlight. The lantern has been run on 6 and 7.5V wall warts I had in the junk box.

    I'm now looking at coming up with another circuit that will use 4 X 1W star LEDs

    What is more important when regulating the power? Voltage or current?

    At present I have a circuit with an lm317 regulating voltage to 7V. Using an online array wizard and specs for the LEDs I have two series arrays (2 LEDs each) arrayed in parallel as per several wizards. Resistors are correct.

    Is there a better way to set this up?

  2. #2
    Flashaholic* bshanahan14rulz's Avatar
    Join Date
    Jan 2009

    Default Re: design considerations

    You can use that LM for current regulation too, which would be much safer for high power LEDs. 5mm and to some extent high-flux (superflux, etc) LEDs do alright with voltage regulation and correct resistors, but power LEDs use more current, so errors are much larger.

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