Abstract: A gear tooth sensor having increased sensitivity and temperature tolerance enables relatively small ferrous targets to be detected, which lends itself for use in relatively compact applications, such as the sensing of an automotive cam shaft drive wheel. All of the embodiments include a magnet having opposing north and south pole faces and a single input Hall effect IC which defines a sensing plane, and may include one or more flux concentrators. In one embodiment the sensor is configured such that the magnet is disposed adjacent the periphery of the target wheel such that the magnetic axis is generally parallel to the direction of travel of the ferrous target at an instant when the ferrous target is adjacent the magnet. In this embodiment, the Hall effect IC and flux concentrator are disposed adjacent one side of the ferrous target wheel and at least partially below the magnet.

Abstract: A rotary position sensor for sensing the angular position of a pivotally mounted device, such as a throttle valve. The rotary position sensor includes a generally circular magnet with a central aperture. A magnetic sensing element, such as a Hall effect integrated circuit (IC) is disposed within the aperture to reduce the overall size of the sensor. In order to improve performance of the sensor, one or more flux concentrators are disposed adjacent the magnetic sensing element within the central aperture of the magnet, while keeping the overall size of the sensor to a minimum to enable the sensor to be utilized in applications where space requirements are generally critical, such as automotive applications.

Abstract: The present invention relates to a variable reluctance sensor which includes a coil of wire defining a pair of output terminals, one or more stators or pole pieces, and an injection molded bobbin formed from a magnetic material and a polymer binder for carrying the coil wire. The injection molded bobbin magnet enables the size and, thus, the strength of the magnet to be increased while not increasing the overall space requirements of the sensor. In addition, the injection molding enables the inner diameter of the bobbin to be formed in the image of the toothed target wheel relatively easily and inexpensively to additionally improve the output voltage of the sensor. In order to facilitate assembly of the sensor, the bobbin can be formed with integral tabs adapted to be received in corresponding notches formed in the stators, which allows for relatively quick and easy orientation of the stator relative to the bobbin.