What are the parameters of laptop power adapter commonly used?

Laptops have limited functions, such as power requirements of only 50-70 watts (W). In recent years, power requirements have climbed above the 100 W range, but weight and size expectations have not improved accordingly. In addition, the need to meet the specification's low standby power performance, external power supply (EPS) efficiency requirements, and the harmonic requirements of IEC1000-3-2 for input power above 75 W make this challenge even more difficult to deal with. This article explores recent trends that enable power manufacturers to address these challenges and offers different alternative solutions to choose from.

As laptops become more versatile, so do their power requirements. Also, because the battery capacity (or density) has increased, so have the charging requirements -- hence, the power requirements of the laptop adapter have doubled. However, for the millions of people around the world who carry laptops, larger and/or hotter Power Adapters are not a very attractive option. The attraction is a small, lightweight laptop adapter that recharges instantly. Of course, it doesn't generate heat, and it doesn't cost much. Recent developments in electronic products have not increased our hopes in this regard, and it remains an open question whether future revolutions can be realized. We also wanted to be able to use a laptop adapter globally without a 110/220 volt operating voltage selector switch -- so the laptop adapter had to be designed for truly universal line voltage operation. Regulatory and OEM expectations also play a role.

Regulators want laptop adapters that don't waste energy or add harmonics to power lines. The first factor is that after the adapter is plugged without any load, it should absorb as little power as possible (stand-by requirements). It is common practice for people to plug their laptop adapters into an outlet without connecting the computer, and this requirement can prevent loss in this situation. The second factor is recent regulations that require specific average power efficiency for different load conditions (25 percent, 50 percent, 75 percent and 100 percent) to be enforced by global regulatory bodies in order to promote compliance with the code and reduce overhead costs. Finally, harmonic-reduction requirements mandated by the European Union and Japan have begun to be applied to laptop power adapters as they exceed the 75 W input power threshold of these standard specifications. In a sense, the mobile/universal nature of the laptop adapter made it the first mass-produced power product to be covered by the IEC1000-3-2 specification.