| 摘要 |
PURPOSE: To provide a device and method for detecting both open and closed circuit failures in a solenoid controlled actuator used for a speed regulator. CONSTITUTION: The open and closed circuit failures of a solenoid actuator are detected by branch resistors R1 and R4 that are provided while being branched to a solenoid 1, a transistor switch 4, and a voltage monitor 7 and/or a voltage monitor 14 for detecting a non-excited solenoid that suffers from an open circuit failure or an excited solenoid that suffers from a closed circuit failure while being connected to either one or both terminals. Before each change of an actuator position, all solenoids are excited to opposite states for an amount of time that is not sufficient for moving the actuator but is sufficient of checking the response of the voltage monitor, thus detecting all open circuit and closed circuit failures. |
