well, there will be having many kind of LED around.. But with different kind of voltage, is tat necessary to produce diff kind of color? Heard that there is some kind of LED able to do that...mind to tell? thx.

there Are leds that will change color with Votage difference in way of Polarity.

one way it`s Red the other it`s Green and with AC it`s Yellow.

 

is this the type you ask of?

The color is going to depend on the voltage, since you need a larger bandgap as you move from red to blue. There's some addtional overhead in the circuit, too, but a 1 Volt drop can't give you more than 1 eV, which is a wavelength of ~ 1240 nm. Here is a chart of colors vs voltages of a sample of different LEDs.

The color is going to depend on the voltage, since you need a larger bandgap as you move from red to blue. There's some addtional overhead in the circuit, too, but a 1 Volt drop can't give you more than 1 eV, which is a wavelength of ~ 1240 nm. Here[/url'] is a chart of colors vs voltages of a sample of different LEDs.

oic, that helps a lot~! thx