Voltage regulator or resistors to manage LEDs?
I want to run a load of LEDs mounted onto a PCB. This is simple enough.
I'd like to know what's best, using LEDs with resistors (with a little help from http://led.linear1.org/led.wiz)
Or using a voltage converter (with a little help from http://www.reuk.co.uk/LM317-Voltage-Calculator.htm), and doing away with resistors
Source voltage will be either 4.8 (4 NiMH AAs) or 12V (old wall transformers), LEDs will be white ones (3.3v)