Okay, so some good debate between two non-electrical engineers. Will see when Wes decides to chime in. But here is the curve from the Cree XR-E
Your talking in theory, I'm talking in practical control. Anyone who deals with system dynamics, knows that you want to operate on any flat portion of a response curve. If your system is operating above 3 volts. You are going to see much more current swings. Unless your operating against your current limiting resistors in your system. Light output is a function of current not voltage. So if you want consistent light output, then you need to control current.
Well then explain how my system works if it's "theory". You cannot fully dim the LEDs with the way i do it as there wouldnt be enough for the LED to actually function if trying to dim them to dark. But like i was saying with my system, i dont dim my lights. It turns on at 750mA and remains that all day. If i want to bing them down to 350mA or bring them up to 1000mA i can just increase it's voltage. Using a constant current system like a meanwell will allow you to dim them all the way down to dark by controlling the current that goes through them. But if this isnt the option you are trying to achieve (like in mine) then this doesnt matter.
But comparing a CC unit to just a PSU with a fuse unit is in a way comparing apples to oranges. I chose the PSU way because for 128 LEDs, i saved a lot of money by not buying a CC device to run every 8 LEDs.
But also like you see in the diagram, increasing the voltage of the LED above its operational voltage does increase its current. But you must stay within 3-3.7vf for it to operate properly.
meanwell $29
from what i read, people run only 12 LEDs off these.
48v psu $48
I could run 105 off of one PSU and still have enough power for fans. BUT you should only run a PSU under 90% of its potential. So i use 2 PSU's instead of 11 meanwells. $96 vs $319.
If i was to do dimming to dark i can add a PWM which can take care of that.
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