Turn signal LEDs

[Droland]

Hi all,

 I am planning on making turn signals for my motorcycle. To do this I wan to install a row of 5 LEDs spaced about 1/4 inch apart in the plastic side mirrors. To do this I am going to drill 5 holes and have the LEDs coming up through the plastic just proud of the surface. I was consitering using RL3-Y4545 LEDs they are 3mm Dia. 2.2 volt 20 mA with a Luminous intensity of 4500 mcd and a peak imission wavelength of 590 nm.

 I have several questions. First, am I going to have problems with heat, could the LEDs melt the plastic. Second are five LED,s going to be bright enough and is a wavelength of 590 nm withing the leagal range for turn signals.

Thank you for your help.     

[minimum]

Hi.

What causes that heat? If LED's alone are the only "heaters" there, then you dont need to worry, as long you keep voltage/current within limits.
Wavelenght should be just about right (amber) for EU -area. Not so sure about the brightness, tho.

[Droland]

Thanks for the help. I figured that I will just have to test them to see how many LEDs I will need to get it bright enough.

Cheers, 

[Rob]

Welcome to the boards.

I agree with minimum, no real cause for concern on heat.

"Brightness" is very difficult, because it characterizes a human response to the stimulus (light) rather than the light itself. So what looks brilliant in a darkened room may be fairly difficult to distinguish in daylight conditions.

Furthermore, the luminous intensity rating (the number 4500 mcd) wihtout an accompanying beam angle gives only a partial indication of the light output for these LEDs. Outside the beam angle, the power output is less than (maybe a lot less than) half the maximum. So very narrow beam angles will be very bright when viewed on-axis, but quite possibly not even noticeable when viewed off-axis. You'll see that for the same light output, the mcd number goes up as the beam angle goes down. So don't get tempted to buy LEDs based on the highest possible luminous intensity rating (mcd).

The lumen conversion wizard will help you compare LEDs with different luminous intensities and beam angles.