摘  要：介绍了一种应用于混合式步进电机的控制系统，该系统以二相混合式步进电动机的静态和动态运行特性为出发点，主要由控制电路、逻辑合成电路、PWM波调制电路、功率驱动电路、过流保护电路和电流负反馈电路六部分组成。本系统以单片机AT89C51为控制核心，实现正/反转运行、过流保护和电流负反馈功能。针对步进电机随着频率升高带载能力下降的特点，系统通过采用过流保护和电流截止负反馈等措施后，使系统的带载能力有所提高。
关键词：步进电机；单片机；电流截止负反馈

Abstract: A control system for hybrid step motor was presented in this paper.The system which takes the static and dynamic characteristics of two-phase hybrid step motor as the starting point consists of control circuit,logic synthesis circuit,PWM circuit,power drive circuit,overcurrent protection circuit and current cut-off negative feedback circuit.The system takes MCU AT89C51 as the control core and has the functions of forward/reverse working,over-current protection and current cut-off negative feedback.The load capacity of step motor will decrease along with the increase of it’s operating frequency.According to this feature,overcurrent protection and current cut-off negative feedback were adopted to improve the load capacity of the system.
Key Words: Step motor； MCU； Current cut-off feedback