引言由轴共振型弯曲疲劳试验机是研究曲轴疲劳强度的重要设备,试验机的激振系统要求提供高精度和长时间稳定的供电装置(即直流稳速拖动系统)。为了提高测试精度,实现测量自动化,要求实时测量、记录和处理激振频率(转速)、振幅、应变和应力等数据。为此,我们制作了输出功率为5.5瓩,稳速精度为0.1%,稳定工作时间 Introduction The shaft resonance type bending fatigue testing machine is an important equipment for studying the fatigue strength of crankshafts. The excitation system of the testing machine is required to provide a high-precision and long-term stable power supply device (ie, DC steady speed dragging system). To improve test accuracy and automate measurements, real-time measurement, recording and processing of excitation frequency (speed), amplitude, strain and stress data are required. To this end, we have produced the output power of 5.5 瓩, steady speed accuracy of 0.1%, stable working hours