摘要:
A controlled electron mobility galvanomagnetic device comprising a layer of indium antimonide alloyed with a Group 13 isoelectronic element antimonide and doped n-type, the layer disposed on an insulating substrate.
摘要:
A sensor assembly and method for sensing direction of rotation and/or position of an object are provided. The sensor assembly includes a target wheel. A pair of sensing elements may be configured to generate respective signals as the wheel rotates in response to structure on the target wheel. A first circuit may be coupled to receive a signal from at least one of the sensing elements for detecting direction of rotation of the target wheel. A second circuit may be coupled to receive each signal from the sensing elements for detecting position of the target wheel.
摘要:
An analog angle encoder having a simply constructed magnet assembly, wherein rotation of a magnetic field relative to a magnetosensitive device provides a varying output of the magnetosensitive device that varies sinusoidally with the angle of relative rotation. The simply constructed magnet assembly is of a closed-path geometry composed of a single piece of magnetic material wherein only a first portion thereof is magnetized for providing the aforesaid magnetic field for the sensor. The remaining portion of the magnet material (the second portion) remains unmagnetized and does not substantially influence the magnetic field produced by the first portion any more than, for example, air would cause.
摘要:
A method and apparatus wherein a single dual element galvanomagnetic sensor, herein exemplified by a single dual element magnetoresistive sensor (16′), is utilized to sense crankshaft position and rotational speed from the passage of single tooth edges (12′) of a target wheel (10′) by continuous adaptive matching of both MR output signals (VMR1′, VMR2′) during sensor operation. Over a slot (28′) or tooth (26′), both MR output signals should be equal, and if not, they are matched by adjusting the current of one of the current sources (30′, 32′) driving the MRs, performed over a slot or a tooth. Due to higher magnetic sensitivity at smaller air gaps, matching by current adjustment over a tooth is preferred. In a preferred embodiment of the present invention, one MR is driven by a constant current source (30′) while the other MR is driven by a voltage controlled current source (32′). The output voltages of the MRs approximate the tooth pattern of the target wheel; they are high over a tooth and low over a slot. Hence, the signals over the teeth can be simply acquired by means of a peak detector (36a, 36b), one for each MR. The signals from the peak detectors are subtracted from each other in a comparator (36c), and then used as a control voltage (VC) for a voltage controlled current source changing its preset nominal current to a value that minimizes the mismatch of MR signals. If matching of MR signals over slots would be desired, valley detectors would be substituted for the peak detectors.
摘要:
A rotation sensor for high accuracy angle applications such as internal combustion engine crankshaft position sensing includes a pair of complementary target wheels and a dual-element magnetoresistive sensor. The target wheels are spaced from one another along the rotational axis by a predetermined distance. The individual magnetoresistive elements are similarly spaced one from the other and are influence by the ferrite effects of the target wheels. The spacing of the target wheels and magnetoresistive elements are selected in relation to one another and in relation to the mount of axial play in the crankshaft such that changes in ferrite effects of the target wheels upon the elements due to axial displacements of the crankshaft have minimal effect on the accuracy of the sensing apparatus.
摘要:
A motor control includes position transducers for generating crankshaft position and motor position pulse trains. The pulse trains are compared to detect any phase difference between engine and motor. Tables are generated to define the desired phase difference needed for particular valve characteristics. The phase difference represents the instantaneous deviation from the basic profile. One of the tables is selected according to the engine conditions and the motor is driven to achieve the desired phase differences.
摘要:
A device is provided which is capable of generating a surface that at least partially conforms to the contour of an article. The surface is defined by the ends of a number of threaded members which are supported within a suitable support structure. The threaded members are aligned so as to be substantially parallel to and threadably engaged with each other. As a result, rotation of an individual threaded member will cause that threaded member to be longitudinally moved relative to its adjacent threaded members and the support structure, without displacing an adjacent threaded member. The surface can be readily configured manually or automatically to serve as a die or mold cavity when the entire surface has been generated to conform to the entire contour of the article. Alternatively, the surface can be generated so as to provide a suitable fixture surface for supporting and securing a workpiece during a machining or welding operation. Due to its method of generation, the surface can be quickly and repeatedly reconfigured to conform to an article or workpiece having a completely different contour.
摘要:
A cam mechanism is employed to convert motor rotation to reciprocating valve motion. Motor speed is reduced at the valve opening and closing times to reduce stress on the cam mechanism.
摘要:
Each valve of an internal combustion engine is driven by a separate rotary electric motor. A cam mechanism for the valves comprises a cylindrical cam in line with the motor axis and the valve stem, the mechanism having inner and outer cylinders, one cylinder rotating with the motor and carrying a cam and the other containing a cam follower and reciprocating with the valve.
摘要:
A permanent magnet is heated in a pattern by a laser beam to a localized temperature above the Curie point or a temperature sufficient to reduce the magnet coercivity sufficiently for the field of the magnet or an external field to remagnetize the pattern in the reverse direction. Magnets so produced can have very high pole density, digital encoding and analog patterns having gradually varying local field strength.