Thanks everyone. That is all reassuring information. I saw alot of YouTube videos of people powering these with non-current controlled voltage supplies which is why I asked about it but it looks like it's just a bunch of people that don't really know what they are doing. I guess driving them off of a voltage source may work but it probably isn't the safest way to power it.
Petkan:
Current, not voltage source. I explained how to use a chip meant for voltage source to operate as current source.
This means a circuit delivering the same current into a short circuit as into a series of LEDs, no matter how many (up to a limit defined by max output voltage)
If I set the voltage to be 30v then turn up the current until I get to 3A, this should control the LED well. However, lets say I then use a logic level N-channel Mosfet to dim the LED to half the power with pwm after I set the current and voltage... Will this in turn make the power supply only deliver half the current? Would the power supply then try and force more current through by supplying a higher voltage? But then It wouldn't allow any more voltage because I set the limit to 30V, so it would really only be able to supply half the current? Would someone mind telling me if my reasoning is correct? Thanks!