An Evaluation of Low Cost Power Supply Alternatives for High Volume Consumer Products

Many low cost consumer products commonly found in house holds are employing some rather complex electronic systems. Economies of scale allow the implementation of these systems in products that are retailed around the US$10 mark or lower. In such applications cost is a prime driver. Transformer based linear type power supplies are a simple solution, but they are not cost effective and they are too bulky. This paper reviews examples of low cost, low power (sub five Watt) consumer power supplies and compares their advantages and disadvantages. The power supply configurations are a step down rectifier circuit, and a none-isolated offline buck converter. This paper is of a tutorial nature and covers design pitfalls, as well as details of electromagnetic compatibility and product safety considerations