Semiconductor Components Industries, LLC

Sanyo Electric Co., Ltd.

Sanyo Semiconductor Co., Ltd.

Kazumasa Takai

Yoshihiro Niwa

Takeshi Naganuma

Kosaku Hioki

Fumio Kumazawa

Masanori Okubayashi

Hitoshi Yasuda

Masaki Yamashita

Masatoshi Sato

Tomonori Matsumuro

Tomofumi Watanabe

Toshiyuki Shutoku

Hiroyuki Morihara

Implementations of a resolver sensor system may include a signal amplifier portion configured to be coupled to a magnetoresistive sensor coupled with a movable element where the signal amplifier portion configured to receive a sine signal and a cosine signal from the magnetoresistive sensor; and a sensor offset canceling portion coupled with a signal amplifier portion. The sensor offset canceling portion may be configured to generate a direct current offset correction signal to the signal amplifier portion which uses two or more amplifiers included in the signal amplifier portion to receive the sine signal and the cosine signal and to generate corresponding adjusted digital sine and cosine signals. The signal amplifier portion may be configured to provide the adjusted digital sine signal and the adjusted digital cosine signal to one of the servo signal processor or the system controller for use in determining a position of the movable element.

Offset cancel systems and methods for resolver-type sensors

A method of driving a three-phase motor includes, while a first phase is energized, driving a second phase using a first drive function which is sinusoidal. The first phase is switched to a non-energized state and a back electromotive force (BEMF) voltage of the first phase is detected. For at least a portion of a time when the first phase is non-energized the driving of the second phase depends on the output of a second drive function different from the first drive function. The second drive function may be non-sinusoidal and may be a cosine function. The second drive function may drive the second phase when the output of the second drive function is a modulation ratio less than 1. When the output of the second drive function is a modulation ratio greater than or equal to 1 the second phase may be driven to a modulation ratio of 1.

Drive methods for a three-phase motor

Implementations of methods for sensing rotor positions of a motor may include coupling a controller with a PMSM and applying, using the controller, a plurality of vectors to the PMSM, the plurality of vectors including a plurality of dummy vectors and a plurality of measured vectors, wherein at least one measured vector is applied quadrature to a dummy vector from the plurality of dummy vectors immediately preceding each measured vector. The method may also include measuring, with a measurement circuit, a plurality of values from a three-phase inverter coupled with the PMSM, each value of the plurality of values corresponding with one of the plurality of measured vectors, and calculating, with one or more logic elements coupled with the PMSM, based on the plurality of values and using one or more position algorithms, a position of a rotor of the PMSM relative to a stator of the PMSM.

Rotor position sensing system for three phase motors and related methods

A system and method for sensing rotor position of a three-phase permanent magnet synchronous motor (PMSM) includes a controller coupled with the PMSM and causing a plurality of voltage pulses to be applied thereto. A timer and/or an analog-to-digital converter is coupled with the PMSM and measures a plurality of values (measured values) from a three-phase inverter coupled with the PMSM. Each measured value may correspond with one of the plurality of voltage pulses and includes a current value or time value corresponding with an inductance of the PMSM. One or more logic elements calculates, based on the measured values and on one or more position algorithms, a position of a rotor of the PMSM relative to a stator of the PMSM. The system is configured to calculate the position of the rotor when the rotor is in a stopped configuration and when the rotor is in a rotating configuration.

An amount of a motor drive current is controlled to an appropriate value. Two coils are provided, and a rotor is rotated by the coils by setting different phases for the supplied currents to the two coils. During a phase where one of the coils is in a high-impedance state, an induced voltage generated in the coil is detected. According to the state of the induced voltage, an output control circuit controls the amounts of the motor drive currents supplied to the two coils.

Driver circuit and method

A drive-signal-generating circuit includes: a current-detecting unit to detect a current flowing through a three-phase motor; a calculating unit to calculate d- and q-axis currents based on a detection output of the current detecting unit; a reference-signal-output unit to output a reference signal indicating a first-reference value of the q-axis current for rotating the motor at a target-rotational speed; first- and second-control-signal-output units to output first- and second-control signals corresponding to respective errors between current values of the d- and q-axis currents and a second and the first reference values, respectively; a drive-signal-output unit to output such a drive signal that the d- and q-axis currents reach the second and first reference values, respectively; and an adjusting unit to adjust the detection output so that a ripple of the second-control signal become smaller, after a rotational speed of the motor reaches a predetermined rotational speed corresponding to the target-rotational speed.

Drive signal generating circuit

When a driver unit is in a high impedance state as viewed from a first coil or a second coil, an induced voltage detector detects the voltage across the first coil or that across the second coil so as to detect an induced voltage occurring in the first coil or the second coil. The induced voltage detector includes a differential amplifier circuit for differentially amplifying an electric potential across the first coil or that across the second coil, and an analog-to-digital converter circuit for converting an analog value outputted from the differential amplifier circuit into a digital value and outputting the converted digital value to a control unit. The control unit generates a drive signal based on an input signal set externally and adjusts the drive signal in accordance with the induced voltage detected by the induced voltage detector so as to set the adjusted drive signal in the driver unit.

Motor drive circuit for rotating a rotor by supplying the currents to two coils

Driver circuit for driving a stepping motor

A coil current detector detects a current component flowing through a coil. A scaling unit scales a drive signal. An induced voltage component extraction unit extracts an induced voltage component by removing the drive signal, scaled by the scaling unit, from the coil current component detected by the current detector. A phase difference detector detects a phase difference between the phase of the drive signal and that of the induced voltage component. A signal adjustment unit adjusts the drive signal so that the phase difference detected by the phase difference detector can be brought close to a target phase difference.

Motor drive circuit for driving a synchronous motor

The effect of chattering on the measurement of the pulse period is reduced. The pulse period representing the rise interval of target pulses appearing in a pulse signal PI is measured. The pulse signal PI is sampled in synchronization with a measurement clock CLK. Measurement of a designated inhibition period is started in synchronization with the fall of the signal PI. Measurement of the current pulse period is completed and measurement of a new pulse period is started if the inhibition period has elapsed at the rise of the signal PI. Counting of the current pulse period is continued if the inhibition period has not elapsed.

Pulse period measurement method

A differential amplifier detects a coil current Is at the time of steady rotation of a synchronous motor. An application voltage Sat this time is detected from an output of an ATT circuit and so on. With the use of the coil current Is which is detected, the application voltage Sat that time, and a predetermined scaling factor As, an induced current Ib is obtained based on Ib=As&#xb7;S&#x2212;Is. The application voltage to the motor is controlled based on the induced current Ib which is obtained.

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Kakamigahara, Japan

Kazumasa Takai