This very clever circuit will convert 1.5v to 10v to take the place of those expensive 9v batteries and also provide a 5v supply for a microcontroller project. But the clever part is the voltage regulating section. It reduces the current to less than 8mA when no current is being drawn from the output. With a 470R load and 10v, the output current is 20mA and the voltage drop is less than 10mV. The pot will adjust the output voltage from 5.3v to 10v.