Do I have to use transitors for each R,G,B line of all the 5 ledstrips?
That would be 15 transistors on the pcb!
s there a better solution?
I saw the ULN2803 but that chip would assume that the strips have acommon kathode, right?
Each strip takes approximately max. 30-40mA while fading through allpossible colors.
No that is a current sink so it assumes you have a common anode strip.
Are you sure?
Sorry... to be honest in the ULN2803 schematics I believed that the chip has common GND andall the outputs are positive.
What purpose has pin 10 (COM) of the ULN2803 if not VCC?
Should I put limiting resistors before the inputs of the ULN2803 orcould I directly route the traces from the 74HC595 to these inputs?