Patent ID: 9048751
Filing Date: 2015-06-02
Classification: H02M,Y02B,Y02P

Abstract:
1. A power supply circuit configured to generate a DC voltage at a target level from an AC voltage, comprising: a rectification circuit configured to output a rectified voltage obtained by rectifying the AC voltage; an inductor configured to be applied with the rectified voltage; a transistor connected in series with the inductor, the transistor configured to increase an inductor current flowing through the inductor when turned on; a diode connected in series with the inductor, the diode configured to output the inductor current when the transistor is turned off; a capacitor configured to be charged with a current from the diode and generate the DC voltage; a detection circuit configured to detect the inductor current; and a switching control circuit configured to the target level corresponding to a level at which the diode is turned on when the rectified voltage rises, when the rectified voltage rises and the diode is turned on, the inductor and the capacitor respectively having an inductance value and a capacitance value for allowing the inductor current larger than the reference current to flow, the reference current corresponding to a current when the level of the DC voltage is equal to the target level.