| 摘要 |
An electric actuator is provided having the same configuration whether used as an ordinary electric actuator or as an electric actuator having an emergency shutoff function. A portion for supplying power during a power failure, a power failure detection circuit, and a motor power supply switching circuit are provided in a module detachably coupled to the electric actuator. When failure of primary power is not detected, the power is sent to the electric actuator by the motor power supply switching circuit. When failure of the primary power is detected, secondary power is sent to the electric actuator by the motor power supply switching circuit. In addition, notification of the power failure is sent from the module to the control board of the electric actuator, via a relay connector. After being notified of the power failure, the control board reads a specified aperture during a power failure from a memory, and drives the motor with secondary power from the module as the energy source, thereby setting the aperture of the valve to the aperture during a power failure. |
