Hi every one,
I'm renovating my bathroom and put up some powerLED spot(down)lights.
I like to have them controlled by a microprocessor so i can use remote controller, nice fadeing etc..
I got good experience with arduino. So that my candidate.
Every spot is setup with 3 * Z-LED P4 - natural white. I really like this LED not to blue(cold) nor yellow(warm).
Each LED have ratings 350mA 3.2V 1.2W and in the setup each spot have 350mA 9.6V 3.36W. I have a heatsink attached so i can go up little more.
I found that ST L200 regulator is more or less made for this.
Its a current and a voltage regulator. 2A, 2.85V-36V
The Current Limit Sense Voltage is 0.45 so 1 ohm will regulate the current to 450mA. and that should be ok.
I like to use voltage regulator part to control the dimming.
What i really need help with, is to use one of the PWM pin from arduino to control L200 voltage. MIN PWM will be 5.5V and MAX PWM will be 9.6V
Vo is calculated as Vo = Vref (1+ (R2/R1)). Vref is ~2,77
Any one have used PWM to control voltage regulator?
Here is the L200 PDF Datasheet **broken link removed**
Many thanks,
::Beppe