| 摘要 |
PROBLEM TO BE SOLVED: To prevent reduction in power-supply efficiency.SOLUTION: A PFC circuit generates a sinusoidal current with the same phase as an AC input voltage and corrects a power factor. A DC-DC converter converts an output signal from the PFC circuit into a predetermined voltage. A current change detection unit detects the amount of change of an output current from the DC-DC converter and compares the detected current change amount and a preset threshold value. The current change detection unit outputs a gain switching signal for rising the gain of an output voltage of the PFC circuit when the current change amount exceeds the threshold value. The current change detection unit outputs a voltage control signal for rising the output voltage of the PFC circuit to a predetermined value. A voltage setting unit sets the output voltage of the PFC circuit to the predetermined value on the basis of the voltage control signal. |
