Abstract: A temperature monitoring circuit and control system for compensating for self-heating effects of a thermistor used for measuring a temperature within a system includes a thermistor, a pull-up resistor, a node configured to receive a reference voltage, and a node configured to supply a sensed voltage; the control system measures a voltage across the thermistor; determines a thermistor resistance based on a known supply voltage and a known biasing impedance supplying current to the thermistor; determines thermistor temperature based on the thermistor resistance; determines a thermal rise value due to thermistor self-heating based on the known supply voltage, the thermistor's heat dissipation constant, and the calculated thermistor resistance; and creates a compensated thermistor temperature value by subtracting the thermal rise value from the determined thermistor temperature thus providing a more accurate measurement of the device being monitored by the thermistor.

Abstract: A rotating electric machine includes a shaft angle sensor communicating with an external controller via differential signaling. This construction permits the controller to be located away from the axial end of the motor while reliably transmitting rotor angle or speed information to the controller over a relatively long electrical harness. The shaft angle sensor is mounted on a sensor board carried by the machine casing at the non-drive end of the rotor shaft. The sensor board can optionally act as a hub at which signals from multiple machine sensors are gathered to be placed in communication with the controller via the same electrical harness used to transmit the sensor information.

Abstract: A rotating electric machine with a rotor shaft having a target magnet. High current conductors conductively couples inverter circuitry with the stator windings. Control circuitry and a magnetic position sensor facing the target magnet are disposed on a printed circuit board, the printed circuit board being axially positioned between the target magnet and a heat sink. The high current conductors extend axially from proximate the heat sink to the stator assembly and are positioned radially outwardly of the magnetic position sensor. A ferrous shield member has a major surface defining a plane perpendicular to the rotational axis. The magnetic position sensor is axially disposed between the shield member and the target magnet and the shield member is positioned between the printed circuit board and the heat sink. The shield member has a surface area covering most of the area radially inward of the high current conductors.

Abstract: A variable reluctance sensor interface module having a variable attenuation circuit and a rectifier and differential to single-ended conversion circuit for operating in a current mode to attenuate a differential input voltage. The variable attenuation circuit receives an input differential voltage from a magnetic sensor, converts the differential voltage to current, and variably attenuates the current. The rectifier and differential to single-ended conversion circuit converts the variably attenuated current to a voltage output. The input circuit includes an RC filter that attenuates high frequency signals. An initial threshold circuit generates an initial threshold voltage that compensates for internal resistance variations.

Abstract: A variable reluctance sensor interface module having a variable attenuation circuit and a rectifier and differential to single-ended conversion circuit for operating in a current mode to attenuate a differential input voltage. The variable attenuation circuit receives an input differential voltage from a magnetic sensor, converts the differential voltage to current, and variably attenuates the current. The rectifier and differential to single-ended conversion circuit converts the variably attenuated current to a voltage output. The input circuit includes an RC filter that attenuates high frequency signals. An initial threshold circuit generates an initial threshold voltage that compensates for internal resistance variations.

Abstract: An improved method of measuring vehicle speed based on the output signal of a variable reluctance speed sensor responsive to the teeth of a transmission output gear adjusts the sensitivity of a signal processing circuit in dependence on the mode of operation of the vehicle so as to reduce sensitivity to output signals produced by gear tooth vibration. The signal processing circuit only passes portions of the sensor output signal that have an amplitude greater than a predefined threshold and a frequency less than a predefined frequency, except when an electronic controller identifies a condition of potentially erroneous speed sensing characterized by substantially stationary vehicle operation with the engine decoupled from the output gear and an engine speed in excess of a calibrated threshold.

Abstract: An inductive load energized by a variable duty cycle pulse signal contains ripple at steady state conditions, and the average current is used as feedback to a controller. The average current is obtained without filtering by synchronously sampling the local maxima and minima of the current and averaging the last two samples. The maxima and minima are detected by sampling at the falling and rising edges of the pulse signal. The method is implemented by software in a microprocessor or by hardware comprising a pulse generator, sample and hold circuits, and an averager. The resulting average value is then asynchronously sampled by a microprocessor.