Variable reluctance sensor

Abstract: A throttle controller for an internal combustion engine employs a stepper motor to move the throttle valve and provides a controller to permit the use of the stepper motor. The stepper motor requires no return spring or position sensor and hence offer weight and cost advantages. The throttle position is deduced by means of an up-down counter tracking movement of the stepper motor during throttle control. The controller includes an integration means to accommodate the unknown starting throttle position. A fuel cutoff solenoid is activated in the event of over-speed or power loss. An engine speed signal for the controller is produced by a variable reluctance sensor providing a signal to a slope detector circuit to eliminate the influence of external magnetic fields.

Abstract: The circuit comprises a comparator 1 fed by a quasi-sinusoidal signal delivered by a source 2 for converting the positive alternations of the signal into pulses acceptable by digital computing means. According to the invention, the circuit comprises a current source 7 selectively connectible to the circuit in order to vary its sensitivity and to thus enable an evaluation of the amplitude of the signal delivered by the source 2. Application to the diagnosis of the operating state of a variable reluctance sensor delivering a quasi-sinusoidal signal representing the speed of rotation of a shaft fitted in a motor vehicle.

Abstract: The radial dimension of selected teeth in toothed wheels used for measuring the transmitted shaft torque are changed in a predetermined spatial pattern corresponding to desired information. Such embedded data structures within the torque measurement apparatus may be used for encoding data uniquely related to the shaft twist modulus of a particular torque meter. In this manner, the toothed torque and/or reference wheels may be used to "self-compensate" or "program" appropriate electronic signal processing apparatus so as to automatically take the particular shaft twist modulus fully into account before producing output torque measurement data. At the same time, the use of such different radial tooth dimensions provides a differential amplitude modulation component in the sensor output signal which may be used to sense the relative gap dimensions (i.e., between rotating toothed wheels and a variable reluctance sensor) such that this variable parameter can also be taken fully into account by the signal processing electronics before a final output torque measurement signal is produced. Compensation for shaft speed and sensor temperature variations may also be achieved so as to result in final measured torque output data automatically compensated for variations in shaft modulus, gap, speed and temperature.

Abstract: A security system that includes an inductive sensor commonly known as a "proximity sensor" or "variable reluctance sensor", an alarm unit, and a controller that allows a user to position the movable structure on which the sensor is mounted, e.g., a door or window, at a selected position and then arm the security system with the structure in that position to detect movement of the structure away from the selected position. For example, the user may open a window on which the sensor is mounted and then arm the alarm to trigger upon detection of movement of the window from that position or, alternatively, only upon detection of further opening of the window or, alternatively, only upon detection of closing of the window. A user could thus open a window a small, selected amount to admit fresh air without triggering the security system or open a door a small, selected amount to receive a caller or allow pets to enter or leave the premises without triggering the security system.