DC motors remain very important for control system applications in two main areas: (a) High-power drives where precise variable-speed control is required. (b) Servomechanisms. Although AC machines, in conjunction with solid-sate electronics have made great progress, DC machines have also been the subject of improvement. For small power applications, permanent magnet motors are now very competitive. Compared with their wound-field counterparts they have a higher torque at zero speed and an almost linear torque-speed characteristic. For very low-power applications, small moving-coil DC motors can complete thousands of stop-start cycles per second. They find most application in computer peripherals, such as tape readers.