Home-made 10W RGB LED driver?

Other Hardware LEDs and Multiplexing
1

Hi,

I want to control 10 pcs. of 10W RGB LEDs at 12V, including being able to change the color of each LED seperately, preferably at high speed.

I'm thinking that I can control them over I2C bus with several PCA9685, each giving me 16 PWM outputs.
But obviously I cannot draw the current from the chip, so what else can I do?
Essentially I want to amplify the 5V PWM output. Since each channel R,G,B might have different maximum voltages, I'm planning to provide a constant 12V, 11V and 8V VDC power source.
So, perhaps the 5V PWM output could serve as a signal to a high-speed transistor, thus resulting in respectively 12V, 11V or 8V in PWM form?

Is this a good design? Is there a better way?

2

If the supply is constant current you do not need to specify a voltage, that is taken cair of automatically.
Therefore you don't need to amplify the PWM to a voltage, just use the PWM to turn on or off your constant current drive.

This is a typical constant current drive, but the parts shown will not drive 10W.

Constant Current.png
Constant Current.png601×513 6.52 KB

3

I'd try one of these LED driver boards at TINDIE.com