Abstract: A method and apparatus for measuring current by a single sensor for two motor phases driven by first and second set of switches to drive respective first and second phases of a motor under control of PWM signals. A first step 100 includes reading a duty cycle of each winding drive current. A next step configures 104, 110, 114, 116, 118 the PWM signals to provide at least one timing window wherein at least of one of the windings of the motor is being driven while the other winding is not being driven, and to provide a relative timing offset of approximately one-half cycle between the pulse width modulation signals driving a first winding and a second winding of the motor. A next step 90 includes gating the switches with the configured PWM signals. A next step 95 includes sampling the current of the at least one of the windings with a single sensor.

Abstract: A method and apparatus for measuring current by a single sensor for two motor phases driven by first and second set of switches to drive respective first and second phases of a motor under control of PWM signals. A first step 100 includes reading a duty cycle of each winding drive current. A next step configures 104, 110, 114, 116, 118 the PWM signals to provide at least one timing window wherein at least of one of the windings of the motor is being driven while the other winding is not being driven, and to provide a relative timing offset of approximately one-half cycle between the pulse width modulation signals driving a first winding and a second winding of the motor. A next step 90 includes gating the switches with the configured PWM signals. A next step 95 includes sampling the current of the at least one of the windings with a single sensor.

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 method and apparatus for measuring current by a single sensor for two motor phases driven by first and second set of switches to drive respective first and second phases of a motor under control of PWM signals. A first step 100 includes reading a duty cycle of each winding drive current. A next step configures 104, 110, 114, 116, 118 the PWM signals to provide at least one timing window wherein at least of one of the windings of the motor is being driven while the other winding is not being driven, and to provide a relative timing offset of approximately one-half cycle between the pulse width modulation signals driving a first winding and a second winding of the motor. A next step 90 includes gating the switches with the configured PWM signals. A next step 95 includes sampling the current of the at least one of the windings with a single sensor.

Abstract: A method and apparatus for measuring current by a single sensor for two motor phases driven by first and second set of switches to drive respective first and second phases of a motor under control of PWM signals. A first step 100 includes reading a duty cycle of each winding drive current. A next step configures 104, 110, 114, 116, 118 the PWM signals to provide at least one timing window wherein at least of one of the windings of the motor is being driven while the other winding is not being driven, and to provide a relative timing offset of approximately one-half cycle between the pulse width modulation signals driving a first winding and a second winding of the motor. A next step 90 includes gating the switches with the configured PWM signals. A next step 95 includes sampling the current of the at least one of the windings with a single sensor.

Abstract: A method and apparatus for measuring current by a single sensor for two motor phases driven by first and second set of switches to drive respective first and second phases of a motor under control of PWM signals. A first step 100 includes reading a duty cycle of each winding drive current. A next step configures 104, 110, 114, 116, 118 the PWM signals to provide at least one timing window wherein at least of one of the windings of the motor is being driven while the other winding is not being driven, and to provide a relative timing offset of approximately one-half cycle between the pulse width modulation signals driving a first winding and a second winding of the motor. A next step 90 includes gating the switches with the configured PWM signals. A next step 95 includes sampling the current of the at least one of the windings with a single sensor.

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: An apparatus (100) for measuring torque and flux current in an AC synchronous drive motor (108), having a shaft (110) magnetically coupled to an a-phase stator, a b-phase stator and a c-phase stator, includes a shaft position indicator (112) that is coupled to the shaft (110) and that generates a position signal indicative of a position of the shaft (110). A current sensing circuit (114) generates a current signal indicative of instantaneous direct link current of the motor (108). A sample and hold amplifier (116) samples the current signal when a trigger input is asserted. A processor (120) asserts the trigger input from trigger generation (124). The processor (120) calculates torque generated by the motor (108) and flux current in the motor (108) based on the current signal value and decoding algorithm (122).

Abstract: A method for measuring the current in each phase of a three-phase motor (26) by the sensor (32), the motor (26) being controlled by a plurality of switching devices (S1-S6) that receive pulse width modulation signals from a controller (34). In one embodiment, a first and second sampling window (t1 and t2) are monitored. When both the first and second sampling windows (t1 and t2) are less than a minimum sampling window (mw), the voltage pulse trains associated with the highest output (V_h) and the lowest output (V_l) are shifted to form a first modified sampling window (t1′) and a modified second sampling window (t2′). When the first sampling window (t1) is less than the minimum sampling window and the second sampling window (t2) is greater than the minimum sampling window (mw), then the voltage pulse train associated with the highest output (V_h) and/or the middle output (V_m) may be shifted to form the first and second modified sampling windows (t1′ and t2′).

Abstract: An apparatus (100) for measuring torque and flux current in an AC synchronous drive motor (108), having a shaft (110) magnetically coupled to an a-phase stator, a b-phase stator and a c-phase stator, includes a shaft position indicator (112) that is coupled to the shaft (110) and that generates a position signal indicative of a position of the shaft (110). A current sensing circuit (114) generates a current signal indicative of instantaneous direct link current of the motor (108). A sample and hold amplifier (116) samples the current signal when a trigger input is asserted. A processor (120) asserts the trigger input from trigger generation (124). The processor (120) calculates torque generated by the motor (108) and flux current in the motor (108) based on the current signal value and decoding algorithm (122).

Abstract: A method for measuring the current in each phase of a three-phase motor (26) by the sensor (32), the motor (26) being controlled by a plurality of switching devices (S1-S6) that receive pulse width modulation signals from a controller (34). In one embodiment, a first and second sampling window (t1 and t2) are monitored. When both the first and second sampling windows (t1 and t2) are less than a minimum sampling window (mw), the voltage pulse trains associated with the highest output (V_h) and the lowest output (V_l) are shifted to form a first modified sampling window (t1′) and a modified second sampling window (t2′). When the first sampling window (t1) is less than the minimum sampling window and the second sampling window (t2) is greater than the minimum sampling window (mw), then the voltage pulse train associated with the highest output (V_h) and/or the middle output (V_m) may be shifted to form the first and second modified sampling windows (t1′ and t2′).

Abstract: Control methods for operating a power converter circuit, consisting of a full bridge DC/DC converter stage and a full bridge DC/AC inverter stage, for use in automobiles and other vehicles. The DC/DC converter is operated by pulse width modulation and by “soft switching” and “synchronous switching” which involves turning MOSFET switches OFF and ON at strategic times to gain improvements in system performance. The DC/DC converter is also operated at a relatively high and relatively constant duty cycle, and is controlled in such a way as to make the output operate as a current source. The DC/AC inverter has a cycle by cycle overload current protection scheme.

Abstract: A three-phase invertor and control is disclosed for synthesizing low harmonic content AC voltage in the non-linear, or overmodulation, region of inverter operation. A field orientation control provides a reference voltage vector representing the desired AC output voltage in magnitude and angle. Three state, two state, and step inverter operations are used individually and in combinations in accordance with magnitude and angle parameters of the reference voltage vector.

Abstract: A DC Link for use with a multi-phase DC to AC converter provides soft-switch opportunities to the main inverter devices only when such opportunities are required. A quasi-resonant rail swings from source to ground potential either with or without the assistance of an auxiliary switch. The quasi-resonant rail swings from ground to source potential with the assistance of an auxiliary switch. Low switch stresses are characteristic in both the main inverter switch devices and the DC link switch devices. Main power is carried predominantly through a DC link switch thereby minimizing power handling requirements of DC link reactive components.

Abstract: A DC Link for use with a multi-phase DC to AC converter provides soft-switch opportunities to the main inverter devices only when such opportunities are required. A quasi-resonant rail swings from source to ground potential either with or without the assistance of an auxiliary switch. The quasi-resonant rail swings from ground to source potential with the assistance of an auxiliary switch. Low switch stresses are characteristic in both the main inverter switch devices and the DC link switch devices. Main power is carried predominantly through a DC link switch thereby minimizing power handling requirements of DC link reactive components.

Abstract: A lighting system comprising: an AC power line; an electronic ballast including structure for receiving and interpreting commands transmitted on the power line to control dimming of a fluorescent lamp, the ballast including structure defining an individual address, the ballast including structure for initiating an arc to start the fluorescent lamp, for limiting current through the fluorescent lamp after the arc is initiated, and for dimming the light output of the fluorescent lamp; and a control element spaced apart from the electronic ballast and including structure for sending commands on the power line in a format that the ballast is capable of interpreting, the control element including structure for sending an address with the command, the ballast including structure for comparing the sent address with its individual address and responding to the command if the sent address matches its individual address.

Abstract: An inverter circuit operating from line utilizes minimum, lower rating switches to operate at higher frequency, while maintaining substantially unity power factor and lower input current harmonics. The input rectified DC is transferred to a storage capacitor using a buck-boost regulator in which the current in inductor is always maintained discontinuous and proportional to the instantaneous input voltage. Filtering this input current will give substantially sinusoidal current at the input. The second switch in the buck-boost regulator and an additional third switch contributes to the necessary half bridge for an inverter. The inverter, which can be self oscillating or driven from a control circuitry, can give higher frequency, high voltage AC output with ability to control the load power hence provide for dimming, e.g. for a fluorescent lamp.

Abstract: An electronic ballast circuit for multiple fluorescent lamps. Control is achieved by varying the voltage and the frequency of operation of an inverter utilized to drive the fluorescent lamps. A separate voltage boost converter provides regulated voltage to the converter. Dimming is accomplished by varying the voltage either manually or in response to sensor circuitry.