ABSTRACT
Most household electronic products and office equipment circuitry are operated internally at a low direct current (DC) voltage. However, they are designed to be plugged directly into wall outlets with alternating current (AC). AC to DC conversion is performed by devices called DC power supplies. Energy efficiency is a serious concern for most electrical and electronic appliances that require power supplies to operate. The majority of end users consume excess energy because of inefficient, bulky, and outdated power supply systems. A great gap exists in studies on energy saving in power supply design and selection. This article presents an overview of power supply energy consumption patterns and the effects of different operation modes on overall system power consumption. Recommendations for achieving an efficient energy system are presented.