Power LED Review
There are many different power LEDs from manufactures. Even the same LEDs mounted on different boards. I have some high power LEDs that I bought for the LED shield. Here is a brief review on these for the people who consider to buy one of those.
350mA White LED
The LED is one of most common 350mA white LED and is copycat of famous Luexeon I. I bought it from Sparkfun but it is likely sourced from China. It come with MCPCB. Measured Vf=3.18 at 350mA
700mA Cree XR-E Q2
Cree is a big name in the high power LED industry. They are simply cutting-edge in term of LED chip technology along with Philips. They are making one of the most efficient LED in the market. XR-E is also quite efficient 700mA line. “Q2” is the bin codes which indicate basically brightness LED among the same XR-E. There are quite a bit of price difference depending on bin code. Better bin code means brighter and better efficiency. (P2 bin – 67lm, Q2 – 87lm, Q5 – 107lm, all at 350mA, minimum flux). You can buy XR-E P4, Q2, Q5, R2 bins from dealextreme. Measured Vf=3.62 at 700mA
700mA Cree XR-E Color
These are red, green, blue LEDs that are same series with white XR-E. Bought them from dealextreme as well. they are efficient and bright but don’t have any bin code. Color LED have slightly different wavelength depending on bin code. Since they are three separate LED, they are not good for RGB color mixing. Lens from Sparkfun can be used with these three LEDs for color mixing though. If you know any place I can buy Cree RGB mounted on single MCPCB, please let me know. Measured Vf at 700mA are red = 2.16V, green = 3.65V, blue =3.2V
3W (350mA x 3) RGB LED
This is basically 3 LED dies (Red, Green, Blue) combined in a chip. Each color is rated 350mA. I bought it from sprakfun. Almost same kind are widely available from many places. Since 3 different LED dies are in a chip, it has very good color mixing. Quility of build is just fine. Solder points are a bit too close. Be careful not to make a short. Measured Vf at 350mA are red=2.36, green = 3.24, blue = 3.18
10W (350mA x 3 x 3) RGB LED
When you want to have a powerful RGB LED that has a good color mixing, this is what your looking for. This LED is exactly 3x 3W RGB LED above. This LED has 3x 350mA in series for each color. This is not exactly 10W more less 8.8W, but still very bright. Quality of build is very good. It is cheaper than similar 700mA Lumiled comination. Measured Vf at 350mA are red=6.39V, Green=9.38V, Blue=9.22V
700mA Philips Lumiled Color
Philips is another big name in LED market along with Cree, Osram, SSC and so on. They make very efficient 700mA. Unlike Cree color led, you can easily find RGB LEDs that are mounted on single MCPCB or FR-4 PCB. Believe or not red big PCB (from Sparkfun) and small white star MCPCB (from ledsupply) have same kinds of LEDs. They have all Three RGB 700mA Lumileds. A difference in LEDs is one from Sparkfun has royal blue rather than ragular blue. Royal blue is the way how Philips call deeper blue (shorter wave length). MCPCB has smaller thermal resistance than FR-4 PCB. Small thermal resistance means cooler LED (about 10 Celsius degree difference). Due to the larger size of PCB (Sparkfun), it has poorer RGB color mixing.