Patent ID: 8159198

Claim:
An apparatus for efficient power supply operation at variable input line voltages, the apparatus comprising: a detection module that senses an input line voltage to a power supply and determines whether the input line voltage is a high voltage or a low voltage; a primary module that sets a boost voltage of a boost stage of the power supply to a first voltage in response to the detection module determining that an input line voltage is a low voltage and that sets the boost voltage to a second voltage in response to the detection module determining that the input line voltage is a high voltage, the second voltage higher than the first voltage, the boost stage comprising a direct current (“DC”) to DC switching power supply wherein the input line voltage provides input power to the boost stage and the boost voltage comprises a regulated output voltage of the boost stage; a turn module that: sets a turns ratio of a transformer to a first turns ratio in response to the detection module determining that the input line voltage is the low voltage, wherein the transformer electrically connects a primary side of a buck-derived stage of the power supply to a secondary side of the power supply, wherein the transformer is a component of the buck-derived stage of the power supply, the buck-derived stage connecting the primary side of the power supply to the secondary side of the power supply, the boost voltage comprising an input voltage to the buck-derived stage, an output of the buck-derived stage comprising an output voltage of the power supply, the output voltage comprising a DC voltage regulated to a voltage lower than the boost voltage; and sets the turns ratio of the transformer to a second turns ratio in response to the detection module determining that the input line voltage is the high voltage.