. To do this, I was thinking of running all of them off a single PWM channel on the arduino and dimming them in unison using some sort of amplifier
Has anyone got experience of this that could maybe point me in the right direction with regard to hardware and how to configure it?
I'm scrolling through Eagle
Well as it's in the car, there will be 12v, but probably not particularly clean. Safer to use my clean 5v feed?
There seems to be a lot of different types of FETs... Any idea what kind I should use? I'm scrolling through Eagle and there are millions of them!
I guess I need to build a test rig then and play with resistance to determine brightness. Putting a bigger resistor on to reduce the brightness - would this generate much heat if all the backlights are on? I guess probably not...
If the voltage drop across each (white) LED is 2.7 volts
I'd just use a bipolar NPN transistor instead of the FET. It's being turned hard on and off, so it won't burn much power,