Resistor Question

[kingcobra5352]

So I'm doing a build with a RRW tri cree LED. If my calculations are correct I need a 1.5ohm 1.5w resistor for the reds but the only one the shop has are 1.5ohm 5w. I know these should work but they are a lot bigger than your average resistor. Anybody has an issue with these fitting in a hilt?

[Silver Serpent]

That resistor value is a little high.

(3.7v - 2.65v) / 1A = 1.05 ohm. You could use the 1.2 ohm 3 watt resistors from the store. Depending on your sound board, you could also use the 1 ohm 2 watt resistors and tweak the resistance with the board settings.

[kingcobra5352]

Using the nano biscotte v4. I was always told to round up the voltage of the power source since a full charge 3.7v battery is closer to 4v. Is that not correct?

[Silver Serpent]

I've always used 3.7v in my calculations, even with the older LEDs that were more prone to popping with voltage. The Cree LEDs are very robust, and are safe to use once they're mounted on the TCSS heat sink.

[TheUnchosenOne]

Another good source for resistors is DigiKey. They have an absolutely massive selection.