Electronic motion control systems fall into two basic categories: DC motion control and AC motion control. There are several different types of DC and AC motion control systems. Each type capitalizes on the characteristics of the electrical power being used and the characteristics of the motor being driven.
DC motion control is commonly used in applications where high starting torque or constant torque over a wide speed range is required. Typical applications include conveyors, wire coil winders, extruders, and machine tools (axis and spindle drives). These applications usually result in sudden increases in the physical load on the motor. AC motion control is commonly used in applications that require precise speed control and efficiency. These applications include robots, machine tools (axis and high-performance spindle drives), and storage/retrieval systems.
Many of these applications were at one time considered mainly DC applications. However, because of improvements in AC drive technology, AC drives and motors now perform the same operations at a lower cost. This is made possible because AC drives are smaller, use more efficient motors, and are less expensive than DC drives.
