Arduino-Controlled RGB LED for Lighting || Transistor Choice Help

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-live wire-

Joined Dec 22, 2017
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I am working on a project where you control the color, brightness, and and pattern of an RGB LED through an Arduino Nano. I have programmed it to output 3 variable PWMs (R, G, B of the LED) based on what you select through a rotary encoder. This works well. However, I want to use brighter, higher power LEDs.

I am going to use an old printer charger that can supply 31V at 2.4 amps (and thankfully has short-circuit protection) as the power supply for the RGB LED. I suspect that there is actually a max of 2 amps, so just to stay on the safe side, I am not going to try to power anything that draws more than ~1.5A.

I could use some help choosing the components to scale it up and finish this project.

I need help finding an RGB LED that has the following characteristics. A lot of the things are hard to look for, and for some things you just don't know until you buy it. So suggestions would be helpful.
-All colors are very bright (but not so much so that it temporarily blinds you if you look into it, anything less is ok).
-It disperses light well (so maybe 120-180 degrees).
-It mixes colors well and has good-looking colors (unlike very cheap RGB LEDs you might buy in bulk).

-It draws no more than 1.5A at 31V (so 45W).
-The forward-voltages of all the colors are about the same.
-It does not require special constant-current or other drive circuitry, and has clear common gnd, R, G, and B. Essentially I don't want to have to do anything too complicated to power it. I do not really care if the component life is shortened by using constant voltage, as long as I don't have to constantly replace it. I do not really plan to use it a ton.
-It is not to hard or expensive to get a heat sink for it, and one would ideally be built in.

-It must be, of course, RoHS.

I also need help choosing a switch to control the high-power LED through the Arduino. Mechanical relays would completely fail, and solid-state ones would probably do pretty poorly too. Those PWMs for the LED go up to ~10 kHz. However, transistors, like MOSFETS or IGBTs or BJTs, have the necessary switching speed. But there are so many choices, and some of them require a lot of external circuitry.

Which kind of transistor requires no more than 20-40mA gate to collector to act as a closed mechanical switch (low fV, saturation resistance), requires little to no external drive circuitry (maybe just a resistor or two), can handle up to a few amps at over 31V, and will not be difficult to heat sink? Essentially I am looking for the most Arduino compatible one that can also handle the printer charger power. Some suggestions would be great, thanks.
 
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