After selecting a stepper motor , choosing the right driver becomes paramount. Driver quality and lifespan are certainly important factors in driver selection. Therefore, for the stepper motor to operate, the driver's voltage and current must be determined. Before addressing questions like, "How should the voltage and current of the stepper motor driver be determined?" and "How should a stepper motor driver be matched?", the first step is to understand the relationship between the stepper motor's speed, torque, and voltage and current. This will allow for informed decisions later.
1. When the stepper motor is fixed, the voltage supplied to the driver has a great impact on the motor performance. The higher the voltage, the greater the torque that the stepper motor can generate, which is more beneficial for applications requiring high speed. However, the heat generated by the motor increases with the increase of voltage and current, so it is important to ensure that the motor temperature does not exceed the maximum limit.
II. A reference value: The input voltage of the stepper motor driver is generally set to 3 to 25 times the rated voltage of the stepper motor. Recommendation: Use DC 24V-48V for 57-frame motors, DC 36-70V for 86-frame motors, and above 80V for 110-frame motors.
3. The DC power supply obtained by stepping down the transformer, then rectifying and filtering, can be selected according to the following engineering empirical formula: C = (8000XI) / V (uF) where I is the winding current (A); V is the DC power supply voltage (V).
Previously, we discussed what a stepper driver is and introduced some common fault analysis and troubleshooting techniques. Next, we summarize several precautions for stepper motor drivers, as detailed below. When connecting a stepper motor to the driver, please ensure the motor power is off first. The motor must not be disconnected while the driver is powered on. We strongly recommend against connecting the motor leads to the ground or power supply.
Precautions:
1. The drive should be installed in a well-ventilated environment. When multiple drives are used in the same cabinet, the distance between them should be no less than 30mm. If necessary, a cooling fan should be installed.
2. Before powering on, ensure that the positive and negative terminals of the power supply are connected correctly to avoid damaging the driver by reversing the connection.
3. First, use a multimeter to measure each phase and the intermediate tap of the motor. Only turn on the power if the connection is correct.
Four-wire motors can only be connected in one way; six-wire motors can be connected in two ways: series and center-tapped. In series connection, the motor has greater torque at low speeds, but cannot run as fast as when center-tapped. In series operation, the motor needs to operate at 30% less current than in center-tapped mode to avoid overheating. Eight-wire motors can be connected in two ways: series and parallel. Series connection provides greater torque at low speeds and less torque at high speeds. In series operation, the motor needs to operate at 50% of the current in parallel mode to avoid overheating.
Most stepper motors can achieve open-loop control, meaning that the angle and speed of the stepper motor are controlled by the number and frequency of pulses input to the driver signal input terminal, without the need for feedback signals. However, stepper motors are not suitable for long-term operation in the same direction, as this can easily burn out the product. They are best suited for short-distance, frequent movements.
A stepper motor and its driver constitute a stepper motor drive system. The performance of a stepper motor drive system depends not only on the performance of the stepper motor itself but also on the quality of the stepper motor driver. Therefore, pay attention to the above points when wiring and using it to avoid damage!
