So, if I understand you correctly, I need an NPN transistor for each LED string. That's 20 transistors. How would the arduino control that many transistors? (Or did I get you wrong and I only need 1 for all?)
So, if I understand you correctly, I need an NPN transistor for each LED string. That's 20 transistors. How would the arduino control that many transistors? (Or did I get you wrong and I only need 1 for all?)