Patent ID: 9473030
Filing Date: 2016-10-18
CPC Classification: H01M,H02J,H02M,Y02B,Y02E

Claim Text:
1. A switching power supply apparatus comprising: a converter circuit configured to have efficiency characteristics in which power conversion efficiency at a rated load is higher than power conversion efficiency at a light load and that converts power-supply voltage into direct-current voltage to output the direct-current voltage; a switching unit configured to switch supply and shutoff of the power-supply voltage to the converter circuit, such that when the switching unit is switched to shut off the power-supply voltage to the converter circuit, the power-supply voltage is prevented from being input to the converter circuit; a charge unit configured to store the direct-current voltage output from the converter circuit; a detecting unit configured to detect an amount of charge in the charge unit; and a controller configured and programmed to switch the switching unit based on the amount of charge detected by the detecting unit; wherein the controller is configured and programmed to set the switching unit to the shutoff state if the amount of charge in the charge unit is higher than a first threshold value and set the switching unit to the supply state if the amount of charge in the charge unit is lower than a second threshold value; the controller is configured and programmed to output the direct-current voltage subjected to the conversion in the converter circuit and store the direct-current voltage subjected to the conversion in the converter circuit in the charge unit when the switching unit is in the supply state and output the direct-current voltage stored in the charge unit when the switching unit is in the shutoff state; and a frozen period in which the switching unit is in the shutoff state is controlled depending on an increase and a decrease of output power and the frozen period is lengthened with the decreasing output power.