I’m working on a fish tank light assembly using Arduino. I have the design and the code written already, but had a question regarding a resistor in my circuit.
There will be 3 banks of LEDs on the light: one bank of 4 blue LEDs; one bank of blue LEDs; and one bank of red. The blue and white banks will take 12V each from the 12V supply, so no problem there.
The problem arises with the red bank- it only takes 7.2V to run it, so I need to use a resistor. The resistor must be able to dissipate 2W at 16Ohms, and I have no experience working with resistors above 1/4W. Will this resistor need to be heat-sunk? Or is it designed to dissipate the heat well enough?
Also, even though the full 12V will be used in the blue & white banks, should I still use a 1 Ohm 2W resistor?
It should also be said that the circuit will be in a standard radioshack project enclosure.
I attached the circuit schematic as a JPEG.