【通信应用笔记】继电器驱动保护 AN319 APPLICATION NOTE RELAY DRIVE PROTECTION INTRODUCTION A fast switch-off in an inductive circuit causes overvoltages and electromagnetic interferences that can damage peripheral elements. When a relay drive circuit is not protected, it is frequent to find some con- tacts destroyed by the arc due to the overvoltage or failed transistors after initial use. Various solutions exist which limit the voltage at the terminals of the switching circuit in order to prevent any damage. There follow some examples. PASSIVE COMPONENTS Resistive network, capacitor (see circuit a, Figure 1). This is an……