Abstract: A door position control including an electric door actuator having a motor and a motor controller in communication with a system controller. A motor actuation operation is selected from a plurality of predetermined motor actuation operations to provide control signals to the motor controller for controlling actuation of the motor for control of door movement. Control of door movement is effected with reference to parameters specific to an installation location including an angular sweep of the door between open and closed positions and with reference to an available bus voltage for supplying power to the motor.

Abstract: An electric clutch actuator capable of operating in two power loss conditions. For a condition where a normally engaged clutch is disengaged during a system power loss and the desired action is for the clutch to remain in the disengaged positional state, a holding device moves to a power off activated position to prevent movement of an actuator for the clutch. For a condition where the clutch is disengaged during a system power loss and the desired action is for the clutch to move to an engaged positional state, a motor in the electric clutch actuator is used as a generator to convert the potential energy of a clutch pressure spring into electrical energy to provide energy for powering the holding device to remain deactivated, permitting movement of the clutch actuator to the engaged position. Maintaining the holding device deactivated permits the clutch to move to the engaged position and thereby allows vehicle engine braking to be used during a power loss of the system.

Abstract: A door position control including an electric door actuator having a motor and a motor controller in communication with a system controller. A motor actuation operation is selected from a plurality of predetermined motor actuation operations to provide control signals to the motor controller for controlling actuation of the motor for control of door movement. Control of door movement is effected with reference to parameters specific to an installation location including an angular sweep of the door between open and closed positions and with reference to an available bus voltage for supplying power to the motor.

Abstract: An electric clutch actuator capable of operating in two power loss conditions. For a condition where a normally engaged clutch is disengaged during a system power loss and the desired action is for the clutch to remain in the disengaged positional state, a holding device moves to a power off activated position to prevent movement of an actuator for the clutch. For a condition where the clutch is disengaged during a system power loss and the desired action is for the clutch to move to an engaged positional state, a motor in the electric clutch actuator is used as a generator to convert the potential energy of a clutch pressure spring into electrical energy to provide energy for powering the holding device to remain deactivated, permitting movement of the clutch actuator to the engaged position. Maintaining the holding device deactivated permits the clutch to move to the engaged position and thereby allows vehicle engine braking to be used during a power loss of the system.

Abstract: In one method for controlling an electric motor, current turn-on and turn-off rotor-position angles for each motor phase are chosen to substantially maximize the absolute value of average motor torque when the motor is operating in two different quadrants of motor torque and motor speed. The first quadrant has positive motor torque and positive motor speed. The second quadrant has negative torque and positive speed. The third quadrant has negative torque and negative speed. The fourth quadrant has positive torque and negative speed. In another method, the motor is operated in at least one of the first and third quadrants and in at least one of the second and fourth quadrants, wherein the absolute value of motor speed is limited when the motor is operating in the first or third quadrants but not in the second or fourth quadrants. In one example, the motor operates a vehicle brake caliper.

Abstract: In one method for controlling an electric motor, current turn-on and turn-off rotor-position angles for each motor phase are chosen to substantially maximize the absolute value of average motor torque when the motor is operating in two different quadrants of motor torque and motor speed. The first quadrant has positive motor torque and positive motor speed. The second quadrant has negative torque and positive speed. The third quadrant has negative torque and negative speed. The fourth quadrant has positive torque and negative speed. In another method, the motor is operated in at least one of the first and third quadrants and in at least one of the second and fourth quadrants, wherein the absolute value of motor speed is limited when the motor is operating in the first or third quadrants but not in the second or fourth quadrants. In one example, the motor operates a vehicle brake caliper.

Abstract: A device for implementing a method for controlling a switched-reluctance motor having a rotor and excitable phases is disclosed. The device comprises a controller and an interface for implementing a master control routine including a pre-alignment stage, a preliminary stage, and a primary stage. During the pre-alignment stage, the rotor is rotated to an initial position corresponding to one the phases being aligned. During the preliminary stage, the rotor is rotated from the initial position is rotated in a desired direction. During the primary stage, any operational losses are minimized when the rotor is positioned in a holding position.

Abstract: Magnetically permeable, high magnetic saturation, primarily iron NiFe alloys are formed on thin seed layers by sputtering and electroplating. Pole layers a few microns in thickness can be formed of magnetically superlative, primarily iron NiFe alloys in this manner for transducers that may be used in information storage systems. The seed layers may include Ni0.55Fe0.45 or Cr, and the magnetically superlative NiFe alloy may be Ni0.45Fe0.55. The magnetically superlative NiFe alloy has increased concentration of a body centered cubic crystalline phase and/or a decreased concentration of a face centered cubic crystalline phase compared with conventional Ni0.45Fe0.55. A laminated pole structure has a dielectric interlayer along with seed layers and magnetically superlative, primarily iron NiFe layers.

Abstract: Magnetoresist elements having good giant magnetoresistance characteristics of at least 6 percent are prepared by depositing alternating layers of magnetic alloy and non-magnetic copper or copper alloys in a thickness of 22-40 angstroms, which element, as deposited, exhibits ferromagnetic coupling. The multi-layer element, which may include up to 20 bilayers of magnetic material/non-magnetic material is then annealed at a temperature of about 250.degree.-325.degree. C. for a period of at least 15 minutes up to 10 hours. The resulting element exhibits good GMR characteristics which are thermally stable, and insensitive to minor variations in the thickness of the non-magnetic layer.