Analysis and Design of Adapter Met Energy Efficiency Code under Standby Condition without Using Current Sensor and Hysteresis Circuit for Notebook Computer Applications

The main theme of this paper is to present the analysis and design of an adapter for notebook computer. The contributions of this paper include the analysis and design of circuits, including PFC-OFF control and auxiliary circuit which significantly reduces the standby power consumption to meet the energy efficiency specifications under standby condition. Moreover, it is shown that these circuits don´t use any current sensor and hysteresis circuit to reduce the cost and avoid false activation caused by current noise. The specifications of adapter are as follow: universal input voltage: AC 90~265 V, 50~60 Hz; output voltage: 19 V/DC 100 W; standby power (European and Japan specifications): input power <1 W at 265 V/AC input.. Experimental results are presented to fully support the analysis and circuit design. It has been demonstrated that the input power factor is greater than 97% in the whole voltage range and load condition. The power consumption under standby condition is less than 1 W confirming the design and implementation of the circuit