# electronics circuit designing question?

so i am pretty good in electronics, im curently modifing a circuit and just found the value of the resistors with the ohms law. i have to lower from 12volts dc to 3.5 volts dc to a 300mA consuming high powered led with the cathode to the ground. if my calculations are right i would need to use a 30 ohm 3w resistor, should i take a 4w so the heat is not too intense? the led is not going to be light up always, its going to oscillate on music(color organ).

are my calculation right?

are my calculation right?

12-3.5 =8.5VDC

Resistance = V / I = 8.5 / .3 = 28.3 ohms

Resistor P = V * I = 8.5 x .3 = 2.5 watts

So a 30 ohm 4 watt Resistor will work...

A