Hey, I decided to use a MOS FET to help control the voltage to a fan. And I am using a 7805(I Think) to keep the input voltage at a steady 5VDC to a POT. The Pot controls the voltage to the MOS FET, which in turn variably controls the fan. The 7805 gets very hot when I pass in 15VDC even though it is capable of handling 7 -30 V. Why is it getting so hot to the point where I burn my self and the thermal protection turns on? I hope this makes any sense. If you know what I am trying to say, is this a good or efficient way to variable control the fan? Any advice and help would be highly appreciated.