Hi,
I've only basic knowledge in electronics and a question:
I want to animate the light intensity of a high current LED. High current meaning up to 1.5 A.
If the light intensity animation is done by current regulation or PWM isn't important for me, perfect smoothness isn't a requirement. Whatever is easier.
I think some simple npn-transistor base control could do the trick.
The problem is:
If I use a USB 3 connection, which has 5 V and up to 1.5 A, with an Arduino Nano, may the Arduino become unstable, if I animate the LED with, let's say up to 1.4 A, given that the LED has a 3.2 V forward voltage?
You CAN use a resistor to limit-control the current like with a regular little LED but normally a special switchmode constant current (or controlled current) driver is used.
If you want to use a resistor, it will have to be a high-power resistor and a MOSFET driver will work and it will work with PWM dimming. (You can leave out the diode since you have a non-inductive load.)
Your LED will probably need a heatsink too if it doesn't already come with one. They don't get as hot as an equivalent incandescent bulb but the silicon chip can't handle nearly as much heat as a tungsten filament.