Not long ago, notebook computers with limited functions, such as the power requirements of only 50-70 watts (W). In recent years, the power requirements of up to 100 W over the scope, size and weight but do not expect a corresponding improvement. In addition, the need to meet the norms of low standby power performance, the external power supply (EPS) requirements and efficiency of the IEC1000-3-2 on more than 75 W input power requirements of the harmonic make this challenge even more difficult to deal with. This article can explore the power supply manufacturers to meet these challenges of the new trends, and provide various alternative solutions are available.

With the laptop's growing wealth of features, its power requirements increased. In addition, because the battery capacity (or density) increased demands to raise the charge - As a result, notebook adapter power requirements doubled. However, for millions around the world to carry the notebook computer users, more and / or thermal power adapter is not too attractive option. Is attractive to a small light, but immediately be able to charge the notebook adapter. Of course, it does not produce heat, but will not spend too much. In recent years the development of electronic products does not increase our hope and future of the revolution can be achieved remains an outstanding issue. We also want to use a notebook adapter can be used around the world without having to 110/220 volt operating voltage selector switch - As a result, notebook adapter must be truly universal line voltage design work. At the same time, supervision and OEM expectations also played a role.

Regulators hope that the notebook adapter will not waste energy or electricity lines to add harmonics. The first factor is the adapter without any load to insert a plug, it should be as little as possible to absorb the power (standby request). People in general will be used to notebook adapter plugged into the socket, but did not connect the computer, the request can prevent these circumstances arising from the wear and tear. The second factor is the near future, it requires a different load conditions (25%, 50%, 75% and 100%) have a specific average power efficiency by standardizing the global institutions in order to promote compliance with the norms And reduce overhead costs. Finally, enforcement of the European Union and Japan to reduce the harmonic requirements have been applied notebook power adapters because they have more than the standard 75 W of input power threshold. In a sense, the move adapter laptop / common characteristics making it subject to IEC1000-3-2 standard first production power products.