Industrial Circuit Application Note Stepper （工业应用注意步进电路）.pdf

Industrial Circuit Application Note Stepper motor and driver selection Stepper motors are used in many different In data sheets for stepper motors, 57mm PM stepper is illustrated in types of applications this makes it difficult the pull-in and pull-out torque are figure 1. In both cases the winding to recommend a general step-by-step design given, as functions of stepping rate, and driver combination have been flow chart. The design process is more an for different types of motor and driver designed to drive the maximum iterative process, involving experience, cal- combinations. The pull-in torque current through the winding at stand culation and experimentation. The purpose curve shows the maximum friction still without exceeding the maximum of this application note is to show how torque with which, the motor can 7-watt power dissipation for this type system performance is affected by motor and start, at different stepping rates, of motor. driver selection. Some popular motors and without losing any step. In an actual From the chart, we see that the drivers are dealt with, as well as the im- application, this curve has to be output power of the motor can be portance of the gearing between the motor modified to account for the load increased by a factor of six, through and the load. inertia. the use of a bipolar constant current The pull-out curve is of more inter- driver, compared to the basic unipolar est, because it shows the total avail- L/R-driver. The increased output Limits to system able torque when the motor runs at power is a function