I have a computer PSU that I use to power my external fan for my laptop and to charge my iRiver. Computer PSUs have a 3.3v line and i wanted to run my headphone noise canceling function power from that 3.3v but i wanted to know what size resistor i would need to prevent that extra .3v, or would that small amount of voltage not make enough of a difference to worry about
that .3v is most likely alright as usually the rated voltage is +/- 10%. if have a multimeter then check to see what the 3.3v is actually showing for voltage.
