Many a variety of fallacious argument on this issue, it was said: the volt-ampere characteristic of the LED, the voltage is set, the current set. So the constant voltage and constant current effect is the same. Some people say that the constant voltage power supply mains LED lights in parallel should be used, and the LED constant current power supply should be used in series; Some people say that, because the mains LED lights constant current devices, so use constant current power supply; Some people say that using electricity supply should be a constant voltage power supply should be used when using battery power, constant current power supply. As for why such a request, it seems, who also did not understand.
So, what should be a constant voltage power supply, or a constant current power supply?
First look at the LED in the end is what kind of device. LED brightness is proportional to its forward current, and some of the LED structure determines its cooling power. Most LED will give the rated current, such as Φ5 20mA 1W 350mA … and so on, but that does not mean that the LED can only work in those rated current, but does not mean that the led high bay light is a constant current devices. For example, the Cree 1 watt LED and 3-watt LED is the same model, the current increased from 350mA to 700mA power from 1W to increase 3W, so the mains LED lights can be any value between 350-700mA.