Nidec Corporation

Rohm Co., Ltd.

Masaki Yoshinaga

Akiko Ikeda

Taro Amagai

Kengo Araki

Tomohiro Fukumura

Katsuhiko Yoshihara

Toru Takahashi

Takumi Okada

Masato Nakanishi

Yasuo Ishiyama

An offset of an output voltage of a magnetic sensor caused by an external magnetic field is removed. A motor according to a disclosed embodiment includes: a first magnetic sensor that detects a rotational position of a rotor; a second magnetic sensor that is arranged at a predetermined mechanical angle with respect to the first magnetic sensor and detects the rotational position of the rotor; a signal amplifier that amplifies a difference between a first signal which is a signal output from the first magnetic sensor and a second signal which is a signal output from the second magnetic sensor; and a pulse signal generator that converts an output signal of the signal amplifier into a pulse signal.

Motor

An offset of an output voltage of a magnetic sensor caused by an external magnetic field is removed. A motor according to a disclosed embodiment includes: a first magnetic sensor that detects a rotational position of a rotor; a second magnetic sensor arranged at a position shifted by &#x3c0;/N in a rotation direction of the rotor with respect to the first magnetic sensor when the number of pole pairs is N; a signal amplifier that amplifies a difference between a first signal which is a signal output from the first magnetic sensor and a second signal which is a signal output from the second magnetic sensor; and a pulse signal generation unit that converts an output signal of the signal amplifier into a pulse signal.

A motor according to a disclosed embodiment includes: a plurality of magnetic sensors that output sine wave signals having a certain phase difference in order in accordance with rotation of a rotor; a signal amplifier that amplifies a difference between an output signal of each of the plurality of magnetic sensors and an average signal that is an average of the output signals of the plurality of magnetic sensors; and a pulse signal generation unit that converts an output signal of the signal amplifier into a pulse signal.

A motor according to a disclosed embodiment includes: a first magnetic sensor that detects a rotational position of a rotor; a second magnetic sensor arranged at a rotation center of the rotor; a signal amplifier that amplifies a difference between a first signal, which is a signal output from the first magnetic sensor, and a second signal which is a signal output from the second magnetic sensor; and a pulse signal generation unit that converts an output signal of the signal amplifier into a pulse signal.

An arithmetic circuit includes an auto-zero amplification circuit that compensates an offset of an entered differential signal, and a comparator circuit that converts an output signal from the auto-zero amplification circuit to a digital signal. The auto-zero amplification circuit and comparator circuit are provided in the same package.

Arithmetic circuit, control circuit, and display orientation detecting system

A signal processing circuit amplifies a signal of a magnetic sensor that changes according to the magnitude of a magnetic force. The signal of the magnetic sensor is a pair of signals inverted from each other with respect to a reference voltage. The signal processing circuit includes: a high-pass filter that performs a high-pass filtering process on the complementary signals from the magnetic sensor; a differential amplifier that receives the complementary signals having been subjected to the high-pass filtering process by the high-pass filter as a differential input signal and amplifies the differential input signal at a predetermined amplification factor based on the reference voltage; and a comparator that outputs a binary signal indicating a comparison result between an output signal of the differential amplifier and the reference voltage.

Signal processing circuit and motor drive system

A circuit element includes an upper switching device, a lower switching device, an upper diode device, and a lower diode device. An upper drain is connected to a first terminal connected to a positive electrode of a power supply, and an upper source is connected to a third terminal. A lower drain is connected to a fourth terminal, and a lower source is connected to a second terminal connected to a negative electrode of the power supply. An upper anode is connected to the fourth terminal, and an upper cathode is connected to the first terminal. A lower anode is connected to the second terminal, and a lower cathode is connected to the third terminal. The third terminal and the fourth terminal are arranged so as to be able to be short-circuited outside of a package.

Growing community of inventors

Kyoto, Japan

Masaki Yoshinaga