Before, I liked to this circuit so much,because it can use for gave electric power to anything my circuit,which I want to voltage 1.5V to 30V at current less than 1amp.
This have a IC DC voltage regulator or step down dc converter No. LM317 is main of circuit. You can controller volt output with VR1,it was adjust 1.25V – 30V at 1amp normal value of the current load. The capacitor C1,C2,C3 ware duty a suitable filter current output. The LM317 you ought to held a heat sink too. Detail more about made circuit on pcb, you can see on picture.