Voltages and the A4983 Driver

I’m doing some research on A4983 Driver with the built in Voltage regulars and some bi-polar stepper motors before making a purchase. There was a 3.9 volt, 600mA bi-polar stepper motor that caught my eye. However, after reading the specification for the motor supply that needed 8-35 volts for the A4983 Driver I was doubting if I could use it. I know I could adjust the current with the onboard potentiometer. However, I was wondering if I could add a resistor to create a voltage drop for the bi-polar stepper motor, or is there another method?



Hello, Jim.

You do not need (or want) to drop the voltage to the stepper motor. By using a higher voltage, the current is able to ramp up faster, and which lets you get more torque/speed out of the motor. The 3.9 V rating for your stepper motor is the voltage at which each coil draws 600 mA, and it is the rated current you want to avoid exceeding. The A4983 lets you cap the current at this rated 600 mA while using higher voltages, which gives you better performance.

- Ben