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superflux LEDs and PWM ?

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Shadowcrawler

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Hi,

I have read in the datasheet of my superflux LED that they have a continuous forward current of 30mA,
and a peak forward current of 100mA (by 1/10 duty cycle, 0.1ms pulse width).

Now my question:
Is their a difference between useing the peak current with PWM, or the constant current in light and heat produced.

And if I want to use the PWM method do I still need to use a constant current source, or just a resistor an a voltage source.
 

I think, that the best way is use 30mA continuous current from current source built with LM317 for example. You can use resistor and voltage source, but you have to remeber that current changes with LED's temperature in this case.
 

The basic, conventional and the easiest way to supply a LED is constant current. However, it must be low efficiency, especially when you need to adjust its brightness for any specific purpose, or you have to supply LED from wide range of source voltages. At those cases, PWM is the better solution.

For both of circumtances, you can get the same brightness if you give the LED the appropriate currents/duty cycle.

Just "google" on internet, tons of PWM applications of LED over there.

nguyennam
 

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