Patent ID: 10461654

Abstract:
A system and method of operating an a power supply unit with a light load efficiency control system comprising a power regulator circuit for receiving an alternating current (AC) input voltage from within a range of accommodated AC input voltages and including a power factor correction (PFC) circuit and an LLC resonator circuit having a bulk capacitance voltage level and operable to receive the input AC voltage in the power supply unit and where the power supply unit generates a direct current (DC) output voltage for use by a load. The power supply unit having a processor logic core for the power regulator circuit to control a plural stage bulk capacitor voltage level having at least a high step bulk capacitor voltage level for operation when a normal load is applied to the power supply unit and a low step bulk capacitor voltage level for operation under light load conditions and a light load control circuit for receiving a control input voltage representative of the AC input voltage received by the power supply unit, comparing via a comparator circuit the control input voltage to a reference voltage generated to represent a threshold level of AC input voltage, and activating a light load control feedback signal to the processor logic core if the control input voltage exceeds the reference voltage level under light load operating conditions.