在分析传统BUCK电路特点的基础上，提出了一种基于TL494的开关稳压电源设计方案。为了缓解开关电源效率与纹波二者之间的矛盾，该设计方案采用了两个改善措施：开关管代替续流二极管；多个滤波电容并联代替单个滤波电容。通过测试，当电源效率大于85%时，纹波系数可降低到1.6%。另外本设计还具有过流保护功能和负载识别功能。

Based on the analysis of the characteristics of traditional switching power supply, a design of stabilized voltage switching power supply based on TL494 is proposed. The design improves the traditional BUCK circuit and alleviates the contradiction between efficiency and ripple. Two improvements are adopted in the design: switch tube instead of continuous current diode, and multiple filter capacitors in parallel instead of a single filter capacitor. Through testing, the ripple coefficient can be reduced to 1.6% when the power supply efficiency is more than 85%. In addition, the design also has the function of over-current protection and load identification.