| 摘要 |
A phase-control type of closed-loop control system for motors. A reference signal generator generates a digital reference signal having a binary value which varies between first and second values n times during each a-c input voltage cycle. An error signal generator generates a digital error signal having a binary value which varies in accordance with the difference between the desired and actual values of a motor variable such as armature current. The most significant bits of the digital error signal are utilized to select the angular range within which firing signals will be applied to a phase-controlled rectifier network that is arranged to drive the motor. The least significant bits of the digital error signal are compared with the digital reference signal to determine the time, within the selected angular range, when firing signals will be applied to the controlled rectifier network. By use of this technique, the control system provides both precisely timed control events and a range of control which extends over the entire motoring and inverting regions of motor operation. |
