Patent ID: 7781909

Claim:
A control circuit of power supply for outputting plural DC voltages, comprising: a plurality of control units each of which controls any one of the plural DC voltages each having a different voltage value; a voltage changing portion that detects an output current relating to a first DC voltage that is one of the plural DC voltages and sets up at least one DC voltage which is included in the plural DC voltages except the first DC voltage based on the detected output current, wherein the voltage changing portion comprises: a detecting portion for detecting the output current; a comparing portion for outputting a result of comparison between a detection value of the detecting portion and a reference voltage value; and a selecting portion for selecting, by switching, one of setting voltages, each of which is used in setting the at least one DC voltage, from plural setting voltages based on the comparison result, and wherein the first DC voltage and the at least one DC voltage are supplied with different supply destinations, respectively.