I'm sorry in advance to post yet another thread on this. I have read, at this point, over a hundred posts on LED lights, and yet I still have a few questions that I never saw answered. With that said...
Beginner/noob hobbyist here. I've completed a few smaller arduino projects (temperature sensor monitoring of my aquarium, controlling pumps with relays/water level sensors, simple things like that) with success and am now looking to attempt something a little harder. My background is in computer science/programming, so the software side is trivial, but the electronics... well I still have far too much to learn. So feel free to correct any mistakes, or suggest alternatives that would seem otherwise obvious to someone who has a hardware background. I also apologize in advance for mistakes I'm sure to make.
I've looked online for similar projects, but I'd like to do things a bit differently than the usual aquarium led light (which is why I feel a post here is warranted). I'm looking to create a pendant style led light for my aquarium. I plan to control it with an arduino, and I would like anywhere from 8-12 independent pwm channels (not 8-12 colors, but 8-12 truly independent pwm channels). I'm going to be running a number of different led colors (from almost infrared to almost uv, and everything in between) since I'd like to be able to fine tune the color. Since these will be on continuously throughout the day, I'd like to avoid resisters/linear regulators for led power management. The idea is once I build one that works, I can then build a few more (depending on how much lighting I need in the aquarium).
I was hoping to use 3w leds, 1 led for each channel. The idea is to drive the leds with a single constant current power source (perhaps something like the Meanwell LDD) and wire them in series. I could then (at least theoretically) turn the individual leds on and off using a mosfet shunt bypass. This chip was my inspiriation: TPS92661 which seems to do that sort of thing.
After doing more reading though I ended up with more questions than answers. Somewhere (in the tons of posts I've read over the past few days) I came across someone attempting the same sort of thing, and it was stated that pwm shunt dimming would kill a constant current power supply. In another post I read that a CC power supply could be shorted and suffer no ill effects. The existence of the above part (TPS92661) suggest to me it is at least possible, though they use the LM3409 for power regulation in their evaluation/demonstration board.
So to that end. Can I drive a shunt pwm style dimming off a standard led CC driver (like the meanwell LDD's)? If possible something simple like that (ie. an all in one IC) is easier for me. Can I make it work with standard off-the-shelf logic level mosfets? Is something like the TPS92661 easier than just using mosfets (the cost is nearly the same), the TPS92661 seems like it would be above my capability? How would you guys approach this problem?
Thank-you for your time in advance, any advice or thoughts are appreciated.
