How to choose stepper motor driver

1. Checking and confirming the torque required by the stepper motor to drag the load.

The easiest way is to add a lever to the load shaft and use a spring balance to pull the lever. The tension multiplied by the length of the arm is the load torque.Or theoretically calculated based on the load characteristics.

Since the stepper motor is a control motor, the maximum torque of the regular stepper motor does not exceed 45Nm.

The larger the torque, the higher the cost. If the  motor torque is larger or exceeds this range, you can consider adding a deceleration device.

2. Confirming the maximum running speed of the stepper motor.

The speed index is very important in the selection of the stepper motor. The characteristic of the stepper motor is that with the increase of the motor speed, the torque decreases, and the speed of its decrease is related to many parameters, such as: the drive voltage of the driver, the phase current of the motor , The phase inductance of the motor, the size of the motor, etc.

The general rule is: the higher the driving voltage, the slower the torque drop; the greater the phase current of the motor, the slower the torque drop. When designing the scheme, the speed of the motor should be controlled within 600 rpm or 800 rpm/minute. Of course, this is not standardized. You can refer to <Torque-Frequency Characteristics>.

3. According to the two important indicators of load maximum torque and maximum speed, and then refer to <torque-frequency characteristics>, you can choose a stepper motor that suits you.

If you think that the motor you choose is too large, you can consider adding a deceleration device, which can save costs and make the design more flexible. In order to choose a suitable reduction ratio, the relationship between torque and speed should be comprehensively considered, then selecting the best solution.