hello if i order these what else will i need ?

Discussion in 'The Projects Forum' started by dvan, Apr 4, 2014.

  1. dvan

    Thread Starter Member

    Feb 8, 2014
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  2. bertus

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    Apr 5, 2008
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  3. dvan

    Thread Starter Member

    Feb 8, 2014
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    ok i have a heatsink and a power supply but i keep ruining these leds so im gonna try something else
     
  4. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    What powersupply do you have?
    For powering leds, you will need a constant current powersupply, as given in the link.

    Bertus
     
  5. dvan

    Thread Starter Member

    Feb 8, 2014
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    using the one on the far right used has a 12 v a 5 v supply 1.5 amps
     
  6. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Those power supplies are constant voltage.
    When there was no current limiting used with that power supply, the leds will get ruined.
    As stated on the page of the leds, they need to be driven with a current of 350 mA.

    Bertus
     
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  7. dvan

    Thread Starter Member

    Feb 8, 2014
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    so this supply will work with that driver and 10 leds ? thanks again
     
  8. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    The driver in the given link will power 3 to 10 leds in series.

    Bertus
     
    Last edited: Apr 4, 2014
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  9. wayneh

    Expert

    Sep 9, 2010
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    You could use your existing supply if you place a current-limiting resistor in series with the LEDs.

    The choice of resistor value is determined by the desired current (eg. 75% of the maximum spec of the LED), the number of LEDs in series (each has a Vf spec), and the voltage of the supply. The power rating of the resistor should be at least double the expected dissipation, calculated as I^2*R or ∆V*I.
     
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