Effective standby power reduction using non-dissipative single-sensor method

This paper presents an implementation of the "single-sensor" method for controlling a power factor correction (PFC) circuit. The method eliminates lossy resistive feedback by deriving control variables such as the input and output voltages of the power converter via the switching action of the power MOSFET of the power converter. It can be applied directly to control the PFC circuit under all conditions. A simple technique is also introduced to overcome the sensing problem under the no-load condition. This proposed scheme requires only simple modifications of existing PFC control integrated circuits (IC) and can be extended to all other PFC control ICs. Practical results of an 80 W PFC system for 88 V to 265 V operation from no-load to 100% load conditions under both steady-state and transient conditions are included to confirm the success of such implementation. The proposed method can in principle be applied to a wide range of switched mode power electronic systems for reduction of standby power.