Patent ID: 7358463
Filing Date: 2008-04-15
Classification: H02M

Abstract:
1. A switching power supply for supplying electricity to a load device, the switching power supply comprising: a switching element that performs switching for supplying electricity required by the load device, and a heat-producing component the temperature of which increases while the output level of the switching power supply is higher than a rated output level; a memory that stores data for estimating temperature change of the heat-producing component during a period in which the output level of the switching power supply is higher than the rated output level; a sensor for detecting that the output level of the switching power supply has exceeded the rated output level; an estimated temperature computation section that computes an estimated temperature for the heat-producing component by using the time elapsed from when the output level of the switching power supply exceeds the rated output level and the data stored in the memory; a determination section that determines whether the estimated temperature of the heat-producing component has reached a predetermined upper threshold temperature; and a control section that controls the switching element to stop switching when the estimated temperature of the heat-producing component is determined to have reached the upper threshold temperature.