Understanding Stepper Drivers Correctly
Susan.Nan 2025-02-12 15:05:51 77 Views1 Replies I have a project using a NEMA 23 stepper motor , which is a bipolar 4-wire connection and the spec sheet says it is rated at 2.8A/phase and 3.2V. I am using a DM542T digital driver which has a peak current of 42.A and an RMS current of 3.0A. I am using a 36V regulated Meanwell PS which has an output current of 5.9A. So I set the driver to the closest (peak 2.84A) to match my motor. Then I watched Bill's video on large stepper motors and was confused about something. Do we set the driver to "peak amps" or "RMS" and seeing as it is a bipolar motor do I really need to double the amperage (2.8 x 2 = 5.6A) to set it correctly?
I have other questions but I want to first clarify peak vs. rms and the total amps needed to get the setup right.
Thanks,
For your setup with the NEMA 23 stepper motor and the DM542T driver, here are the key points to clarify:
1. **Peak Current vs. RMS Current:**
- **Peak Current (2.84A):** This is the maximum current the driver will supply to the motor during operation.
- **RMS Current (~2A):** This is the continuous current that the motor will effectively use over time, calculated as the peak current multiplied by 0.707 (RMS factor for a sine wave).
When setting up your DM542T driver, **you should set it to the peak current** (2.84A) to match your motor’s 2.8A/phase rating. The driver will handle the RMS conversion internally.
2. **Bipolar Motor Amperage:**
- The **2.8A/phase rating** of your motor is per phase, and since it’s a bipolar motor, you **do not need to double the current**. The driver will handle both phases independently, so you set it to 2.84A (close to 2.8A) to match the motor’s specifications.
3. **Power Supply:**
- Your 36V, 5.9A power supply is sufficient for this setup. The total current draw of the motor (2.8A/phase × 2 phases = 5.6A) is within the power supply’s 5.9A limit.
Summary:
- Set the DM542T driver to **2.84A (peak current)**.
- No need to double the amperage for a bipolar motor.
- Your 36V, 5.9A power supply is adequate for the motor and driver.
Let me know if you have further questions!
R2D2C3PO 