As energy use becomes a greater concern and emphasis on conservation increases, efficiency standards for external adapters has become an issue. The tremendous increase in devices using external adapters has prompted the establishment of minimum requirements for efficiency and no load power consumption for external adapters. The most recently enacted efficiency standard under Energy Star® is commonly called “level V”. It consists of three criteria: 1) active mode – connected to a product or load, 2) no load mode – not connected to a product or load, and 3) PFC – power factor correction. PFC applies to power supplies over 100 watts and will not be discussed here. A detailed description can be obtained on the listed Energy Star website.