Stepper motor drives power unipolar and bipolar stepper motors in full-step, half-step, and micro-step motion control applications. They act as an interface between the controller and the motor, and must match the control signals (voltage and power levels) and signal type (analog or digital). Drive type is the most important factor to consider when selecting stepper motor drives. With unipolar or bifilar stepper motors, current flows in only one direction in each winding. Bipolar stepper motors have two windings through which the drive current is alternated. Most bipolar drives and motors generate more torque than unipolar systems. Full-step stepper motors move in increments of the magnetic detent positions. With a half-step drive, the stepper motor can be positioned midway between the magnetic stop positions. This doubles the resolution and allows the motor to advance to the next magnetic position when the power is disconnected. Micro-step or mini-step motors define a discrete number of angular positions between each full step. Mini-stepping and micro-stepping motor drives use electronic methods to enhance the positional resolution of the control system. 

Stepper motor drives differ in terms of electrical ratings, operating parameters, configurations, and features. Electrical ratings include maximum output voltage, rated power, continuous output current, peak output current, AC supply voltage, and DC supply voltage. Stepper motor drives can use either single-phase or three-phase inputs at 50, 60, or 400 Hz. Operating parameters include specifications for setup and control. Some stepper motor drives have manual controls such as knobs, DIP switches, jumpers or potentiometers. Others include a joystick, digital control panel, computer interface, or slots for PCMCIA cards. Control programs can be stored on removeable, nonvolatile storage media. Hand held devices are designed to be programmed remotely. Wireless and web-enabled controls are also available. Configurations for stepper motor drives include several mounting styles. Most devices mount on a chassis, DIN rail, panel, rack, wall, or printed circuit board (PCB). Standalone devices and integrated circuit (IC) chips that mount on PCBs are also available. Features for stepper motor drives include soft starting; dynamic, injection, or regenerative braking; brake outputs or auxiliary inputs/outputs (I/O); auto-tuning, self-diagnostics, and status monitoring; and alarms for conditions such as overvoltage. 

Stepper motor drives power unipolar and bipolar stepper motors in full-step, half-step, and micro-step motion control applications. They act as an interface between the controller and the motor, and must match the control signals (voltage and power levels) and signal type (analog or digital). Drive type is the most important factor to consider when selecting stepper motor drives. With unipolar or bifilar stepper motors, current flows in only one direction in each winding. Bipolar stepper motors have two windings through which the drive current is alternated. Most bipolar drives and motors generate more torque than unipolar systems. Full-step stepper motors move in increments of the magnetic detent positions. With a half-step drive, the stepper motor can be positioned midway between the magnetic stop positions. This doubles the resolution and allows the motor to advance to the next magnetic position when the power is disconnected. Micro-step or mini-step motors define a discrete number of angular positions between each full step. Mini-stepping and micro-stepping motor drives use electronic methods to enhance the positional resolution of the control system. 

Stepper motor drives differ in terms of electrical ratings, operating parameters, configurations, and features. Electrical ratings include maximum output voltage, rated power, continuous output current, peak output current, AC supply voltage, and DC supply voltage. Stepper motor drives can use either single-phase or three-phase inputs at 50, 60, or 400 Hz. Operating parameters include specifications for setup and control. Some stepper motor drives have manual controls such as knobs, DIP switches, jumpers or potentiometers. Others include a joystick, digital control panel, computer interface, or slots for PCMCIA cards. Control programs can be stored on removeable, nonvolatile storage media. Hand held devices are designed to be programmed remotely. Wireless and web-enabled controls are also available. Configurations for stepper motor drives include several mounting styles. Most devices mount on a chassis, DIN rail, panel, rack, wall, or printed circuit board (PCB). Standalone devices and integrated circuit (IC) chips that mount on PCBs are also available. Features for stepper motor drives include soft starting; dynamic, injection, or regenerative braking; brake outputs or auxiliary inputs/outputs (I/O); auto-tuning, self-diagnostics, and status monitoring; and alarms for conditions such as overvoltage. 

Stepper motor drives use many different types of buses and communication standards. Bus types include advanced technology attachment (ATA), peripheral component interconnect (PCI), integrated drive electronics (IDE), industry standard architecture (ISA), general-purpose interface bus (GPIB), universal serial bus (USB), and VersaModule Eurocard bus (VMEbus). Communications standards include ARCNET, AS-i, Beckhoff I/O, CANbus, CANopen, DeviceNet, Ethernet, small computer systems interface (SCSI), and smart distributed system (SDS). Many serial and parallel interfaces are also available.