Murata Manufacturing Co., Ltd.

Omron Healthcare Company Ltd.

Toshinari Tabata

Gaku Kamitani

Yoshinao Nishioka

Masao Nishimura

Midori Sunaga

Mitsuru Kitagawa

Kenjiro Okaguchi

Hiroyasu Ariga

Naoki Fujii

Ryoji Yamato

Masato Ikuta

A first cell string provided in a first battery module has a larger allowable current value than a plurality of cell strings provided in second and third battery modules. The battery module is provided with a current limiting circuit that limits the charge and discharge currents of the second cell string. When the current value detected by a current sensor is zero, the switch is turned off. In this condition, when the terminal voltage value of the third cell string is different from the terminal voltage value of the second cell string, a second switch switches the connection between the second and third battery modules in order to interpose the current limiting circuit between the second and third cell strings.

Battery pack

In the present invention, a pump driving circuit includes a step-up unit that steps up a first DC voltage from a power supply and outputs it as a second DC voltage, and an H bridge unit that has first and second series circuits that each include two switching elements connected in series between a high potential corresponding to the second DC voltage and a reference potential. According to a control signal from the control unit, the two switching elements of the first series circuit and the two switching elements of the second series circuit are switched on and off. A voltage generated between a first contact point between the two switching elements of the first series circuit, and a second contact point between the two switching elements of the second series circuit is used as a driving voltage for driving a pump.

Blood pressure meter and pump driving system

In a piezoelectric actuator driver circuit, a resistor provided to detect current is inserted in a current path for a piezoelectric actuator. A signal of a decreased voltage of the resistor is subjected to positive feedback to an amplifier circuit via a band-pass filter. An output signal of the amplifier circuit is subjected to negative feedback to the amplifier circuit via a band-elimination filter. The band-pass filter allows a signal of a fundamental resonant frequency of a piezoelectric device, which includes the piezoelectric actuator, to pass therethrough, and the band-elimination filter blocks the signal of the fundamental resonant frequency. Thus, a loop gain at a higher-order resonant frequency with respect to the fundamental resonant frequency becomes very low and a higher-order resonant mode can be effectively suppressed.

Piezoelectric actuator driver circuit

In a piezoelectric-actuator driving circuit for driving a piezoelectric actuator, an amplifier circuit amplifies a signal output from a feedback circuit and supplies the amplified signal to a non-inverting amplifier circuit and an inverting amplifier circuit. The non-inverting amplifier circuit amplifies the output voltage of the amplifier circuit with a predetermined gain and applies the amplified voltage to a first terminal of the piezoelectric actuator. The inverting amplifier circuit inverts and amplifies the output voltage of the amplifier circuit with the same gain as that of the non-inverting amplifier circuit and then applies the amplified voltage to a second terminal of the piezoelectric actuator through resistors. The feedback circuit amplifies a difference between voltages at respective ends of the resistor and supplies the amplified difference to the amplifier circuit.

A piezoelectric ceramic device is heated so that the temperature is increased to a temperature in the vicinity of the maximum temperature at which the device, when the temperature is returned to ordinary temperature, is returned to substantially the same piezoelectric characteristic before heating. In the state that the piezoelectric ceramic device is heated, and the temperature is increased, at least one of the piezoelectric phase characteristic and the impedance characteristic of the piezoelectric ceramic device is measured. The measurement is compared with a standard characteristic, whereby an internal defect of the piezoelectric ceramic device is detected, based on results of the comparison. For the heating and temperature-increasing, and the measuring, a high frequency measurement signal having a power level that is higher than the rated level of the piezoelectric ceramic device is applied, and simultaneously with the piezoelectric ceramic device itself being dielectric-heated by the application of the high frequency signal, at least one of the piezoelectric phase characteristic and the impedance characteristic is measured.

Method of inspecting piezoelectric ceramic device

Capacitor characteristics measurement apparatus and packing apparatus includes a turntable ( ) intermittently driven at a constant pitch to supply capacitors (C) from a parts feeder ( ) to a holder section ( ) of the turntable ( ) in a one-by-one manner. A capacitance measurement section ( ) and an IR prediction section ( ) are provided to determine whether each capacitor is acceptable or defective in quality based on the measured values obtainable from these sections ( ). The IR prediction section ( ) applies a DC voltage to a capacitor while predicting the current value at termination of chargeup by use of its initial current value in the charge region of an insulation polarization component thereof upon application of the voltage thereto. A defective product ejection section ( ) is provided for ejecting defective capacitors and an acceptable product extraction section ( ) is provided for putting acceptable capacity into a storage section ( ) of a base material tape ( ) conveyed by a taping device ( ) and then packing the acceptable capacity by a process including a step of pasting a cover tape onto the base material tape ( ).

Capacitor characteristics measurement and packing apparatus

A capacitor can be charged at a high speed by applying a direct current voltage intermittently to the capacitor. The direct current voltage is intermittently applied to the capacitor such that a preceding applied voltage E,is larger than a succeeding applied voltage E,. Thus, the charging is swiftly progresses and the capacitor can be charged at a higher speed than when the voltage is applied continuously.

Method for charging capacitor

When DC voltages are intermittently applied to a capacitor and when an initially applied voltage E.sub.1 is higher than a subsequently applied voltage E.sub.2, charging rapidly advances even during a period in which no voltage is applied. Higher-speed charging is performed than in a case in which the same voltage is continuously applied.

Capacitor charging method

A method for accurately measuring the insulation resistance of a capacitor while reducing time taken for the measurement. To this end, a current calculation equation is first obtained based on an equivalent circuit of a capacitor; then, the calculation equation is modified or corrected based on the degree of coincidence between an actually measured current value m(t) and a calculated current value i(t), the former being within a charge-up region of a dielectric polarization component upon initial application of a voltage; next, the current value at a time point of chargeup termination is predicted or estimated by use of this modified calculation equation.

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Otsu, Japan

Toshinari Tabata