first of all, I'm sorry if I did not use the technical correct symbols for the circuit diagram, but I think it will do. I've multiple questions. Maybe someone can give me a hint.
I'd like to control two diffrent types of high power LEDs with an Arduino UNO. The 24V power supply is just as an example. There is ofcourse the option to use a smaller one.
1st: I'm not quite shure what kind of other schematics might be usefull. I know there should be at least a resistor before the transistor on the side of the Arduino as well as on the side of the power source, but when I'm looking at some information (http://www.elektronik-kompendium.de/sites/slt/0204302.htm sorry, its in german) it quickly gets complicated and I become insecure what I should do. Same goes for the kind of schematics for the transistor --> 2nd question
2nd: Grounded emitter circuit or common collector circuit? What might be more suitable? Or something completely different?
3rd: The four LEDs in line or better parallel with idividual resistors? What would be the advantage?