I've noticed that pixel controllers seem to have two separate input voltage settings. They seem to be 5V or something like 7V to 40V with the second input option having a range of voltages. Why is this? To me there doesn't seem much difference between 5V and 7V and why once it can handle 7V can it handle up to 40V. Just seems odd that one setting is for 5V and the other setting handles the rest. I'm guessing it's to do with current and that 5V lights are more sensitive to variation in voltage/current. Just bugs me not having even a very basic understanding of how it works. Thanks.