Stepping_Motor

Stepping Motor Construction Stepping motors are electromagnetic, rotary, incremental devices which convert digital pulses into mechanical rotation. The amount of rotation is directly proportional to the number of pulses and the speed of rotation is relative to the frequency of those pulses. Stepping motors are simple to drive in an open loop Static or holding torque - displacement characteristic The characteristic of static (holding) torque - displacement is best explained using an electro-magnet and a single pole rotor (fig. 12). In the example the electro-magnet represents the motor stator and is energized with it's north pole facing the rotor Figure 12 Curve illustrating static torque verses rotor position Assuming there are no frictional or static loads on the rotor, fig. 11 illustrates how the restoring torque varies with rotor position as it is deflected from it's stable point. As the rotor moves away from it's stable position, the torque steadily increases until it reaches a maximum. This maximum value is called the holding torque and represents the maximum load that can be applied to the shaft without causing continuous rotation. If, the shaft is deflected beyond this point, the torque will fall until it is again at zero. However, this zero point step, stepping, motor, phase, torque, rotor, position, static, figure, angle, load, current, fig, steps, shaft, full, switching, number, using, half, stable, pole, follows, field, winding, stator, point, until, switched, sequence, mode, flow, driven, w2, w1