| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce power consumption of an input voltage changing unit.SOLUTION: A CPU 100 outputs a transformer control analog signal ANP for changing an input voltage to a transformer 110 corresponding to a predetermined output voltage, and a transformer control clock signal CLKP for driving the transformer 110. A FET 101 drives the transformer 110 by switching a current flowing on a primary side of the transformer 110 at the frequency of a transformer control clock signal CLKP. An input voltage changing unit 139 for changing the input voltage to the transformer 110 supplies an input voltage based on the transformer control analog signal ANP to the transformer 110 when the transformer 110 is driven. The CPU 100 changes the frequency of the transformer control clock signal CLKP on the basis of an output current detected by an output current detection unit 149 that detects the output voltage of the transformer 110 and the output current of the transformer 110.</p> |
