Abstract: A system and method for reducing torque ripple in a motor controller includes a step (60) of measuring an output voltage at each phase of the motor controller. A next step (61) includes determining a voltage mismatch between the phases. A next step (62) includes phase grounding one phase of the motor. A next step (63) includes calculating a voltage gain for the phases to compensate for voltage mismatches therebetween. The compensating gain can include a gain and/or offset, which are applied as a function of motor angle and is used to generate a PWM signal for driving the motor with reduced torque ripple.

Abstract: While a PWM-controlled, FET-switched three-phase motor is operating in a mechanical damping mode, a single current sensor is used to measure current in the motor. When mechanical feedback into the motor exceeds a predetermined threshold, a bank of the FET switches can be closed to provide damping of the mechanical feedback. This causes currents to circulate within the motor, which an external single current sensor cannot measure to determine current load or when the mechanical feedback is no longer a problem. The present invention periodically switches selected switches necessary to sample the current in at least one phase of the motor to determine when the mechanical feedback into the motor is no longer a problem, while preferably also maintaining an average zero voltage vector.

Abstract: A method and system for detecting faults in an electric power-assisted steering system includes determining a voltage vector of an electric power-assisted steering motor and measuring a current vector of the motor. Acceptable angular relationships are defined between the voltage vector and the current vector, which are then compared to find a fault if the angle does not meet the acceptable angular relationship. Additionally, motor direction and position can also be used against an angular check of the voltage and/or current vector. Similarly, torque direction can be used. In this way, several different faults can be determined dynamically under transient conditions.

Abstract: A printed circuit board having a first switching device (S1 or S2), a second switching device (S3 or S4), a third switching device (S5 or S6), and a common source node (26 or 166) that are each mounted to a surface of the printed circuit board (50 or 150). The printed circuit board further includes at least a first set of conductive paths in a first layer, a second set of conductive paths in a second layer, and a plurality of vias that connects the first layer to the second layer. The first set of conductive paths provides electrical conductivity between the common source node, the first switching device, the second switching device, and third switching device. The second set of conductive paths in the second layer provides electrical conductivity between the common source node, the first switching device, and the third switching device.

Abstract: A fuel injector control circuit and method include first switching circuitry (128, 134, 138, 142, 148, 152, 154) to selectively apply a first electrical signal (171) to a solenoid (114) to vary a load signal (176) between a first maximum (201) threshold and a first minimum (203) threshold. Second switching circuitry (130, 132, 136, 140, 148, 154) to selectively applies a second electrical signal (198) to the load (114) to vary the load signal (176) between a second maximum (205) threshold and a second minimum (207) threshold. The second electrical signal (198) has a magnitude substantially higher than the first electrical signal. Preferably, the second maximum threshold (205) has a magnitude less than a magnitude of the first maximum threshold (201), and greater than a magnitude of the first minimum threshold (203), and the second minimum threshold (207) has a magnitude less than the magnitude of the first minimum threshold (203).