General Interest Texas Instruments Incorporated （一般利益德州仪器）.pdfVIP

General Interest Texas Instruments Incorporated Applying acceleration and deceleration profiles to bipolar stepper motors Jose I. Quinones By Jose I. Quinones (TI) Applications Engineer 1 / Introduction logic. Hence, changing the frequency of the square wave fs With a DC motor, ramping up the voltage (or duty cycle if also changes the stepper’s rate accordingly. DC pulse-width modulation is being used) controls how fast Figure 1 shows a motor manufacturer’s conventional f f s s the motor’s shaft reaches any given speed. With stepper stepping rate/torque curve with an important parameter, motors, however, changing the voltage does not have any fs, called the starting frequency. It must be understood effect on the motor speed. While it is true that changing that, for this particular motor to start properly, a stepping the voltage changes the rate of current charge across the rate smaller than fs must be employed. To start the motor f windings and thus the maximum speed the stepper can with a stepping rate larger than f may induce the motor to