Resistor check appreciated. Need to order soon.

[Zahc Zi Phan]

Hey all. Sorry for re-posting. Wanted to double check my resistors before I got them.

For 5mm RGB common cathode (crystal chamber) wired to PWM signals, each with a FV of 3.3 and run at 18ma:
Red lead 2.0v 18ma: 82ohm 1/8th watt
Green lead 3.2v 18ma: 5.6ohm 1/8th watt
Blue lead 3.2v 18ma: 5.6ohm 1/8th watt

For two 12mm AV switch LEDs, blue and green, each with FV of 3.0v and run at 20ma:
Blue LED 3.0v 20ma: 15ohm 1/8th watt
Green LED 3.0v 20ma: 15ohm 1/8th watt

No resistors for MAIN LEDs. Tri-Cree XP-E2.

Can I use the 82ohm 1/4 watt resistors from the store or do they need to be 1/8 watt? Thanks!!

[Taki117]

You can always go bigger, never smaller so that resistor is fine. Wattage refers to how much heat they can dissipate before breaking down and overheating.

[Rawdo]

Most 5mm RGB I've seen have a 3-3.4v range for green and blue. Would it be ok to go with a "no resistor" option for these two channels?

[Forgetful Jedi Knight]

Most 5mm RGB I've seen have a 3-3.4v range for green and blue. Would it be ok to go with a "no resistor" option for these two channels?

Usually, a minimal resistor is a good idea, as it is an "insurance policy" against accidentally popping the LED, unless you like replacing those LEDs.

[Rawdo]

And I assume accent LEDs end-up most of the time glued in a tight place, so not so much fun to replace..
I'll add a few 0.45ohm resistors to my wishlist then, they should be handy once in a while.

[Forgetful Jedi Knight]

And I assume accent LEDs end-up most of the time glued in a tight place, so not so much fun to replace..
I'll add a few 0.45ohm resistors to my wishlist then, they should be handy once in a while.

Mostly, but that really depends on the builder.