Control output devices - actuators and displays for process automation - part 12 in a series of tutorials in instrumentation and measurement

The principles and applications of dc motors, ac induction motors, stepper motors, solenoid actuators, and micromotors used in process automation are discussed. Their operating principles, characteristics control approaches are outlined. Several output devices typically used in industrial applications are defined. Microactuators, new members of the output equipment family, are also introduced. Several real industrial actuator products and their specifications are described. Computer-based displays and data loggers are introduced and and important technical trends are pointed out. It is clear that future applications of output devices will focus on the development of industrial actuators of smaller size, lighter weight, higher output power and torque, and better static and dynamic characteristics. Novel mechanisms for force generation and more sophisticated machining technique to facilitate the realization of these goals are expected.