FAQs
This page contains questions and answers about our products. If you can't find
answers to you questions here, please see our
product documentation area, or
contact us for more information.
SC125MS and SC125MSX Stepper Motor Driver
Q. What is the difference between the SC125MS driver and the SC125MSX driver?
A.The SC125MS and SC125MSX are identical in function and capabilities, but the SC125MS
comes in an aluminum enclosure with an integrated cooling fan. The SC125MSX driver is the
driver board only.
Q. What types of motors do these drivers work with?
A.These drivers can operate bipolar stepper motors up to 2.5A per phase. These drivers
can drive these types of motors using power supplies from 7V to 30V.
Q. What are "chopper" drives, and do these drivers use this technology?
A.Sometimes stepper motor drives are called "chopper" drives. This refers to the way that
these drives use PWM (Pulse Width Modulation) to limit the current levels in the motors
during operation.
During a normal step the stepper motor driver first turns on the voltage across the windings of
the stepper motor. In a PWM or "chopper" drive, when the current level in the windings reaches
a maximum level the voltage is turned off for a fixed amount of time. The current decays during
this off time until the voltage is turned on again. The current then begins to increase until
it reaches the maximum level again, and the voltage is again turned off for a fixed amount time.
This pattern continues throughout the step until the voltage is turned off at the end of the step.
Our stepper motor drivers use this technology to limit the current in the windings of the stepper
motor. This means that stepper motors can be operated at several times their rated voltage
for increased performance at higher speeds (the increased voltage causes current/torque to
develop more quickly during steps). Our SC125MS and SC125MSX drivers can drive motors from 7V
to 30V, and the current limit in the motor windings can be set from 330mA to 2.5A.