Hello all,
Regarding resistor wattage; the LED calculators out there recommend that for a source voltage of 5V, a LED forward voltage of 2.6V, and a forward current of 28mA that I use a 1/8 W resistor. I am curious how they get this number? I thought it would be 0.14W, so rounding up to a 1/4 watt resistor?:
5V * 28mA = 0.14 W
Or am I suppose to use the voltage drop instead of the source voltage?:
(5V - 2.6V) * 28mA = 2.4 * 28mA = 0.06 W?
Thanks!
Regarding resistor wattage; the LED calculators out there recommend that for a source voltage of 5V, a LED forward voltage of 2.6V, and a forward current of 28mA that I use a 1/8 W resistor. I am curious how they get this number? I thought it would be 0.14W, so rounding up to a 1/4 watt resistor?:
5V * 28mA = 0.14 W
Or am I suppose to use the voltage drop instead of the source voltage?:
(5V - 2.6V) * 28mA = 2.4 * 28mA = 0.06 W?
Thanks!