led colour

Hi i would like to know whether the colour that a led provides can vary according to the voltage drop.I am asking always for the same led.i have a circuit with a potentiometer and a led.The voltage provided to the circuit is 3.80v. The led is white light. When potentiometer allows max power intensity the voltage drop at the led is almost 3,7v that i think it is normal as iam using a white led. When i ghange the potentiometer the light intensity of the led decreases and measured voltage drop is then 2.8v.Is this normal?should not the led have always the same voltage drop independently of the value of the potentiometer?thank you

Posted by kyriakos (kyriakos78@yahoo.com) on 19/07/2005, at 11:46 GMT

Led Colour

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Posted by wal4308 on 14/09/2005, at 22:39 GMT

Led Colour

Varying the voltage/current applied to a LED will not vary the colour of a LED only the brightness.
A LED should be operated in constant current mode, that is that if the voltage varies the current remains the same.
There is no such thing as a white LED. A white LED is usually an ultra violet LED with flourescent material placed in front of it to produce white light

Posted by Wal Douglas on 14/09/2005, at 22:48 GMT