Abstract: Apparatus and methods for reducing unwanted conducted noise generated by a DC load 17. Load 17 is powered by a voltage source 11. A current sense 13 senses pulse current Ifan flowing through the load 17. First converting means 14, 15, 16 converts the sensed pulse current Ifan to a correction voltage Vp. The correction voltage Vp is then converted to a correction current Ip, which offsets the deleterious effects of Ifan. The current Is flowing through the voltage source 11 equals Ifan plus the correction current Ip.

Abstract: Apparatus and methods for reducing unwanted conducted noise generated by a DC load 17. Load 17 is powered by a voltage source 11. A current sense 13 senses pulse current Ifan flowing through the load 17. First converting means 14, 15, 16 converts the sensed pulse current Ifan to a correction voltage Vp. The correction voltage Vp is then converted to a correction current Ip, which offsets the deleterious effects of Ifan. The current Is flowing through the voltage source 11 equals Ifan plus the correction current Ip.

Abstract: An integrated electric motor and controller reduces weight and provides improved performance of devices associated with internal combustion engines such as EGR valves, turbocharger wastegates and the like. The integrated motor and controller includes an electric motor having an output shaft driving a first segmented wheel and adjacent sensor which provide signals regarding the rotation and direction of rotation of the motor output. The motor also drives a gear train having an output member which bi-directionally either rotates or translates linearly. A position coding feature is disposed on the output member and adjacent sensors provide signals regarding the position of the output member. The sensors drive a microcontroller which in turn drives the electric motor. The sensors, the electric motor, the gear train and the microcontroller are all disposed within a common housing.

Abstract: A transfer case for a four-wheel drive motor vehicle includes an electronic control unit (ECU) and a synchronizer which facilitates shift on the fly operations such as, for example, a shift from two wheel high to four wheel high. A temperature sensor disposed either in the transfer case or elsewhere in the motor vehicle provides a temperature signal to the ECU which is utilized to adjust the on time of the synchronizer to compensate for the viscosity of the lubricating fluid within the transfer case or other temperature related variables which affect the time required to synchronize the drive line components prior to engagement. Such temperature compensation also facilitates fault detection and system oversight since the ECU can accurately anticipate the variability of the operating parameters based upon temperature and determinate malfunctions when operation occurs outside such temperature based parameters.

Abstract: An integrated shift motor and electronic controller reduces weight and provides improved performance. The shift control motor includes an output shaft having a first sensor wheel and adjacent sensor which provide signals regarding the rotation and direction of rotation of the motor. The motor drives a gear train having an output member which is coupled to and rotates a shift rail. A sensing wheel is disposed on the output member and adjacent sensors provide signals regarding the angular position of the output member. The sensors drive a microcontroller which in turn drives the shift control motor. Preferably, the sensors, the drive motor, the gear train and the microcontroller are all disposed in a housing. The rotating shift rail includes a pair of spaced-apart followers which engage a cam member which bi-directionally positions a shift fork associated with a multiple position clutch or shift collar.

Abstract: Shift control assembly for a power transmission device includes an electric drive motor and gear train having an output which is coupled to and bi-directionally rotates a shift rail. The shift rail includes a pair of spaced-apart cam followers. Freely rotatably receiving the shift rail and disposed thereon between the cam followers is a shift fork assembly. The shift fork assembly includes a body having a pair of spaced-apart helical cam surfaces engaged by the cam followers and a fork engaging a shift clutch collar. As the shift rail rotates bi-directionally, the shift fork assembly and clutch collar bi-directionally translate. A circular plate is disposed for rotation with the shift rail and includes an array of apertures. A plurality of sensors are disposed in adjacent, sensing relationship to the circular plate.

Abstract: An integrated shift motor and electronic controller reduces weight and provides improved performance. The shift control motor includes an output shaft having a first sensor wheel and adjacent sensor which provide signals regarding the rotation and direction of rotation of the motor. The motor drives a gear train having an output member which is coupled to and rotates a shift rail. A sensing wheel is disposed on the output member and adjacent sensors provide signals regarding the angular position of the output member. The sensors drive a microcontroller which in turn drives the shift control motor. Preferably, the sensors, the drive motor, the gear train and the microcontroller are all disposed in a housing. The rotating shift rail includes a pair of spaced-apart followers which engage a cam member which bi-directionally positions a shift fork associated with a multiple position clutch or shift collar.

Abstract: A shift mechanism position sensor for a transfer case or transmission includes a plurality of Hall effect sensors disposed adjacent a ferrous, metallic plate having a plurality of apertures arranged to provide multi-bit binary signals in gray code. The metallic plate is secured to an internal component such as a shift control rod of the transfer case or transmission and translates bi-directionally adjacent the Hall effect sensors. Data coded in numerous distinct three or four bit binary numbers provides high resolution of the position of the shift mechanism, shift fork and associated clutch. Many four wheel drive motor vehicle transfer cases include a gear reduction assembly which provide direct and reduced speed drives. Such gear selection is often achieved by an electronic control system and it is important to provide information regarding the actual physical position of such gear selection mechanism to the control system.

Abstract: The present invention provides a diagnostic circuit for detecting fault conditions in a Hall effect digital gear tooth sensor in a vehicle's four-wheel drive system. The diagnostic circuit includes a voltage divider circuit connected to a window comparator circuit which is interfaced with a four-wheel drive system controller. Fault conditions, normally difficult to detect in a Hall effect sensor because of the usual open collector configuration, are detected and identified depending on the type and location of the fault. In an alternate embodiment, a safety feature is added to the voltage divider circuit to indicate a fault and prevent gear shifting in the event that the supply voltage and ground wires are inadvertently reversed.

Abstract: A heat sink apparatus dissipates heat from an integrated circuit which is connected to a printed circuit board. A support member is connected to the circuit board for supporting the integrated circuit with respect to the circuit board. A metal tab in thermal communication with the integrated circuit extends from the support member in a plane substantially parallel to the circuit board. An electrically insulating thermally conductive compressible pad is positioned in contact with the metal tab for receiving heat from the tab when compressed. A thermally conductive housing is positioned adjacent the pad for compressing the pad against the tab and for receiving heat from the pad when compressed. The housing includes a plurality of fins extending therefrom for heat dissipation. A method for dissipating heat from an integrated circuit which is connected to a printed circuit board is also provided.