High Power (1w) LED grid, how?

Other Hardware LEDs and Multiplexing
1

Hi,

I'm trying to figure out how to create a led matrix with high power leds, all individually pwm controllable.

The LED's I would like to use are 3.6-3.8V and 300-350mA.

The size of the grid depends on what is achievable, but at least 5x5.

Can I make a normal grid, and use the tlc5940 (3 on each side, combining 3 outputs, so it can handle the 350mA) or similar to control each side?

I've found this topic: http://www.instructables.com/topics/high-power-LED-matrix-is-it-possible-and-how/ and the author shows a 4x4 grid that looks simple to make.

I've been searching the whole day, and I cant find more information (or topics, videos etc), so if you can point me at some that would be great!

2

With high power leds, you need to use constant-current drivers. The drivers need to have pwm control inputs.

I have doubts about your parallel-tlc-chip idea. The 3 chips would not keep their pwm in synchronisation, and the result would be that they could be damaged, I'm not sure. I have not heard of anyone using them in this way.

I would treat anything you find on instructables with great care. Many if not most of the projects on that site are written by people with a poor understanding of electronics. It is notorious for incorrect circuits that are dangerous, or at least lead to the premature failure of components.

3

Maybe you can modify some LED driver like the "3w 12v led driver" or the "300ma dmx512 decoder board" and connect it to a PWM controller (like the PCA9685)

led1.jpg
dmx1.jpg
dmx2.jpg