Patent ID: 8879282
Filing Date: 2014-11-04
Classification: H02M,Y02B

Abstract:
1. A control method for controlling an output power source of a switching power supply, the switching power supply comprising a winding coupled to an input power source, the winding controlling by a switch for charging or discharging, the control method comprising: controlling a peak current flowing through the winding to be a predetermined value; detecting a discharge time of the winding within a switching cycle period; controlling a switching cycle period of the switch to make a ratio between the discharge time and the switching cycle period of the switch approximately equal to a constant value; charging/discharging a capacitor with a first current source in the discharge time; and charging/discharging the capacitor with a second current source in the switching cycle period of the switch; wherein a current ratio of the second current source to the first current source equals the constant value.