Yazaki Corporation

Hironao Fujii

Jian Wang

Saki Oonishi

Kei Matsumoto

Takahiro Syouda

Tsutomu Saigo

Takaaki Izawa

Nobuyuki Takahashi

Yuichi Takahashi

Ayako Saito

A voltage detection circuit includes a differential amplification circuit and a microcontroller unit (MCU). The MCU detects a differential voltage output from operational amplifiers of the differential amplification circuit, and calculates an internal resistance value of a battery cell based on the detected differential voltage. At this time, the MCU controls an amplification factor adjustment circuit of the differential amplification circuit based on a maximum voltage representing the highest voltage detectable by the MCU and the differential voltage output from the differential amplification circuit so as to set the amplification factor of the operational amplifiers.

Voltage detection device

In a battery monitoring device, an amplifier circuit outputs an amplified differential voltage value obtained by amplifying a differential voltage value between a first voltage value of a battery and a reference voltage value, and outputs an amplified differential voltage value obtained by amplifying a differential voltage value between a second voltage value of the battery and the reference voltage value. A CPU calculates an internal resistance value of the battery based on the amplified differential voltage value outputted from the amplifier circuit, the amplified differential voltage value outputted from the amplifier circuit, a current value of a constant current adjusted by a constant current circuit, and a current value of a constant current adjusted by the constant current circuit. The reference voltage value is a voltage value between the first voltage value and the second voltage value.

Battery monitoring device

Provided is a differential voltage measurement device with enhanced measurement accuracy. A differential amplifying unit outputs a voltage corresponding to a difference voltage between a voltage held by the first capacitor and a voltage held by the second capacitor. The &#x3bc;COM connects a battery cell to both ends of the first capacitor, and connects the cell battery to both ends of the second after the first capacitor holds the voltage across the cell battery. SW disconnects the electrical connection between the first capacitor and the negative electrode of and the negative electrode of the cell battery. &#x3bc;COM, after the first capacitor holds the voltage across the cell battery, turns off the SW.

Differential voltage measurement device

A battery monitoring device is provided which improves communication quality, communication stability, and communication reliability. An ECU substrate and detection substrates which cannot directly communicate with the ECU substrate communicate via a relay substrate which is a detection substrate set up as relay of the detection substrates.

An object of the present invention is to provide a battery monitoring device in which communication quality is stabilized and improved. Detection boards are mounted respectively on a plurality of cells arranged in a line, and respectively have a first antenna for wirelessly communicating status information of the mounted cells. A second antenna for receiving the status information transmitted from the first antenna is mounted on an ECU board. The plurality of detection boards and the ECU board are disposed on upper surfaces of the plurality of cells as the same plane. The plurality of detection boards are arranged in a line along an arrangement direction. The ECU board is disposed at the center in the arrangement direction of the cells.

A differential voltage measuring device includes a first capacitor and a second capacitor each formed of a ceramic capacitor, a differential amplifier for outputting a voltage corresponding to a difference voltage between a voltage held by the first capacitor and a voltage held by the second capacitor, and &#x3bc;COM for introducing a first voltage to the first capacitor, and a second voltage to the second capacitor with the first capacitor holding the first voltage, and &#x3bc;COM introduces a third voltage to at least the first capacitor or the second capacitor, and after application of the third voltage stops, introduces the first voltage to the first capacitor or the second capacitor to which the third voltage was introduced.

Differential voltage measuring device

A differential voltage measurement device includes a first capacitor, a second capacitor of which the capacity is smaller than that of the first capacitor, a differential amplification unit which outputs a voltage according to a differential voltage between a voltage held in the first capacitor and a voltage held in the second capacitor, and a control unit which guides a first voltage to the first capacitor and guides a second voltage to the second capacitor in a state where the first capacitor holds the first voltage.

Provided is a battery state detection device suitable for detecting a state of a battery mounted on a vehicle. A &#x3bc;COM uses a first capacitor to measure a first sample of battery voltage, and after a predetermined standby time has elapsed, executes sample hold processing using the second capacitor for performing the second sample hold of the battery voltage. The &#x3bc;COM detects the state of the battery based on the output of the differential amplifier when a condition is satisfied that the battery current is constant during both the first sample hold and the second sample hold and the battery current fluctuates during the standby time.

Battery state detection device

One-side plates of first and second condensers are connected to a one-side electrode of one of a plurality of secondary cells. First switches connect the other-side electrode of the secondary cell to the other-side plate of one of the first condenser and the second condenser. An MCU controls the first switches to connect the other-side electrode of the secondary cell to the other-side plate of the first condenser when the plurality of secondary cells is in a first state, and then connect the other-side electrode of the secondary cell to the other-side plate of the second condenser when the plurality of secondary cells is in a second state. A differential amplifier circuit outputs a differential voltage of voltages of the other-side plates of the first condenser and the second condenser. A cell monitoring IC detects states of the secondary cells based on the differential voltage.

Secondary cell state detector

A voltage detection device for detecting a voltage across both ends of each of plural unit batteries which are connected to each other in series. The voltage detection device includes lowpass filters which are connected to the respective unit batteries, a first voltage detector which detects a voltage across both ends of each of the unit batteries that is supplied via a corresponding lowpass filter, a second voltage detector which detects a voltage across both ends of each of the unit batteries that is supplied without passage through the corresponding lowpass filter, and a failure detector which detects whether the lowpass filter is failing by comparing a voltage detection value detected by the first voltage detector with a voltage detection value detected by the second voltage detector.

Voltage detection device and equalization device

It is provided that pull-down resistors (Rto R) which are respectively connected in parallel to blocks (CBto CB) except for a block (CB) that corresponds to a battery monitoring IC () connected to a main microcomputer (3) via an insulation I/F (4) so as to be capable of communication, thereby equalizing current consumed in battery monitoring ICs (to).

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Susono, Japan

Hironao Fujii