- What is the half-current hold function?
The half-current hold function is a feature of stepper motor drivers that reduces the motor winding current to approximately 50% when the motor is stationary. Even though the current is reduced, the driver still supplies enough holding torque to maintain the motor's position.
- What are the benefits of the half-current hold function?
The half-current hold function provides several benefits:
- Prevents position loss: It keeps the stepper motor locked in position when motion stops.
- Reduces power consumption and heat: Lower holding current decreases both energy use and motor temperature during idle periods.
- Improves system responsiveness: The motor does not need to wait for current to ramp back up when motion resumes, allowing faster restart.
- How do I enable the half-current hold function?
This function is controlled by the SW4 DIP switch on the driver.
- Set SW4 to OFF to enable half-current hold mode (reduced holding current when idle).
- Set SW4 to ON to disable half-current hold mode (full holding current at all times).
StepperOnline open-loop drivers that support this function include: DM422T, DM542T, DM556T, DM860T, and DM2282T.
StepperOnline closed-loop drivers automatically adjust the winding current based on load, which achieves a similar effect without requiring manual DIP switch configuration.
- What impact does the half-current hold function have on stepper motor performance?
The half-current hold function provides sufficient holding torque to maintain position when the motor is idle. However, because only half the rated current is supplied, the available holding torque is reduced. When selecting whether to enable this function, you must weigh the benefits of lower heat and power consumption against the need for maximum holding torque in your application.
- What applications is the half-current hold function suitable for?
The half-current hold function is suitable for applications where the stepper motor must hold position during idle periods, such as precision positioning systems, automation equipment, and robotics. It improves position control accuracy and overall system stability while reducing motor temperature during standby.