what if i have a 5-48V Dc supply (consider that it was varying from 5-48V).. and then i want to have an output of steady 12V Dc.. what will i do? do i need a voltage regulator? what value? and do i need a capacitor coupled in input and output? what value? and 2 resistors connected to adjust terminal of VR? what value? plz help me.. ty..