Hi guys, I have two strips of led (length 1.5 m each), that I'd like to connect in parallell and dim with a simple PWM circuit... I found several example online but my question is? do I need to change resistor/cap values according to my length? Also, what is the circuit you guys recommend? Anyone had experiences?

 

I'd start with the circuit in Fig. 10.4 of Bill's blog on this forum. The timing is independent of the load, if that was your question.