Abstract: A linear actuator having a housing, a plunger slidably mounted to the housing between an extended and retracted position, and an electric motor drivingly connected to the plunger to move the plunger between its extended and retracted positions. A motor circuit controls the activation of the motor circuit and deactivates the motor circuit whenever the motor current exceeds a threshold value which varies as a function of the supply voltage to the electric motor and/or temperature. A memory storage unit stores the position of the plunger. Whenever the position of the plunger is in a state of transition between its retracted and extended position upon system initialization, the motor control circuit activates the motor to drive the plunger to a preselected extended or retracted position.

Abstract: A linear actuator having a housing, a plunger slidably mounted to the housing between an extended and retracted position, and an electric motor drivingly connected to the plunger to move the plunger between its extended and retracted positions. A motor circuit controls the activation of the motor circuit and deactivates the motor circuit whenever the motor current exceeds a threshold value which varies as a function of the supply voltage to the electric motor and/or temperature. A memory storage unit stores the position of the plunger. Whenever the position of the plunger is in a state of transition between its retracted and extended position upon system initialization, the motor control circuit activates the motor to drive the plunger to a preselected extended or retracted position.

Abstract: A sensor failure and detection apparatus and method for use in a redundant sensor system are disclosed. A control circuit disconnects reference power supplied to a sensor and then monitors the voltage decay output by the sensor. The monitored rate of voltage decay of the sensor is compared to the expected natural voltage decay of the sensor to detect failures caused by short or open circuits. An error counter keeps track of the number of failures. After a threshold number of times in which the monitored voltage decay does not compare to a predicted rate of decay, power to the sensor is removed and the sensor is isolated from the system.