Not relay ... at least its not a linear relationship.
The voltage is a product of the junction properties and the current it also varies slightly with temperature.
The output is controlled by the current which must be set independently of the forward voltage.
Output rises with current but the closer you get to the maximum rating the less effect a change in current has.
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No. It's highly non-linear and you get progressively less light increase as you increase current.Hi guy,
I was wondering if a led's lumen is portational to the average current supplied?
Thanks! I would say that is quite linear, apart from sone % drop in efficiency as current goes up.Here's a graph of lumens (in percent) versus current for a XM-L Cree. It is not linear, but that unlinear depending on who's looking at it.
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Read this. The images are from a dig camera, not human eye. As you push higher current, you get less and less brightness increase for your investment, hence it is non linear.Thanks! I would say that is quite linear, apart from sone % drop in efficiency as current goes up.
The really non-linear thing with LEDs is people's eyes!
So for this experiment, I constructed an array of sixteen LEDs in parallel across a 5V source, each with a different current-limiting series resistor.///
Current varied from 6 mA at left to 24 mA at right. variations in brightness are noticeable, but above 10 mA its very difficult to discern differences .
Of course it is.I assume it is something like the human's ears to sound? something like a function of log??
I can tell you that when I buy white LED flashlights and take them apart to soup them up, I have to crank about 6X current through the LED to make the light look about twice as bright. That pretty much follows what the log scale would predict.Thanks guys, that's a lot of useful information for me, even I asked the wrong question.
The mistake I made was, I assumed that the lumen = perceived brightness, now I found out I am wrong.
what I really want to know is, the relationship between the perceived brightness and the average current (PWM).
Yes. Try it to see.Does it mean I can save 50% of energy but only loss little brightness percive by humans eyes? If I do a 50%PWM?