| 摘要 |
<p>STEPPER MOTOR VALVE ACTUATOR The present invention relates to a system for controlling a regulated device. The system includes a power input terminal arranged for connection to a source of AC power; a motor having field coils and a motor shaft and a unit arranged to provide a DC signal. A switch is provided which is connected between the motor and the power input terminal and to the unit for providing a DC signal. The switch is arranged for receiving a first control signal and a lock control signal. The switch is responsive to the first control signal for completing a first circuit between the power input terminal and the motor to apply the AC power to the motor thereby effecting a rotation of the motor shaft in a first direction. The switch is further responsive to the locking control signal to apply a DC signal to the motor thereby effecting the locking of the motor shaft in situ between applications of the first control signal. The motor shaft is thereby driven predetermined incremental amounts in accordance with the first control signal. An actuator is provided, operatively coupled to the motor and arranged for connection to the regulated device. The actuator is responsive to the motor for controlling the operation of the regulated device.</p> |
