Murata Manufacturing Co., Ltd.

Hiroshi Takemura

Tatsuya Hosotani

Akio Nishida

Daisuke Kondo

Hiroki Achiwa

Yasuji Okamoto

Takashi Noma

Nobuhira Tanaka

Yukiharu Kodama

Kenichiro Kawamura

Takanori Koyama

Takahiro Minagawa

Kenjiro Okaguchi

Yoshiyuki Uno

Masaaki Fujisaki

Kiyoshi Kurihara

Hiroaki Wada

Hiroyuki Yokoi

Satoshi Yamaguchi

Yoshinori Ando

Fumi Kitao

Kosuke Narita

A pump includes a housing, a first vibrating body, a second vibrating body, and a peripheral wall portion that define a pump chamber, and a driving body. The housing has a first wall portion opposed to the first vibrating body and a second wall portion. The first wall portion includes a first concave portion that opens toward the first vibrating body and opposed to a central portion of the first vibrating body and a first circumferential portion adjacent to the first concave portion. A first chamber includes a first wide portion defined by the first concave portion and the first vibrating body, and a first narrow portion defined by the first circumferential portion and the first vibrating body. The first narrow portion overlaps with at least part of the first vibrating body.

Piezoelectric pump with an upper and lower vibrating body

A gas control device includes a pump, a valve, a cuff, and a controller. The valve includes a first plate having a first vent hole and a first vent hole, a channel forming plate having an exhaust hole and an exhaust channel, a second plate having a second vent hole, and an edge separation plate. A manchette rubber tube in the cuff is joined to the periphery of the second vent hole in the second plate by an adhesive, and thus the valve is connected to the cuff. The exhaust hole is opened to the atmosphere. The pump includes a pump housing having a discharge hole and a discharge hole. The upper surface of the pump housing is joined to the bottom surface of the edge separation plate.

Valve, gas control device, and sphygmomanometer

A valve includes a first valve housing, a second valve housing, a diaphragm, a first fixing part, and a second fixing part. The diaphragm defines an upstream valve chamber together with the first valve housing. The diaphragm defines a downstream valve chamber together with the second valve housing. The diaphragm is movable between a first position in which the diaphragm blocks communication between the upstream valve chamber and the downstream valve chamber, and a second position in which the diaphragm allows communication between the upstream valve chamber and the downstream valve chamber. When in its second position, the diaphragm makes contact with the inlet of the second discharge channel or the wall surface of the downstream valve chamber to seal between the second discharge channel and the first discharge channel, and when in its first position, the diaphragm allows communication between the first discharge channel and the second discharge channel.

Valve, and fluid control device including valve

A fluid control device () includes a case () including a case top plate, a case side plate, and a case bottom plate and having an internal space () and a cavity, a pump () provided at a position at which the pump () divides the internal space () into a bottom-plate-side region and a top-plate-side region, the pump () being configured to generate a flow of a fluid between the bottom-plate-side region and the top-plate-side region and control the flow direction of the fluid, and a fixing member () that fixes the case () in place. The case () is mounted on the fixing member () by using the case top plate or the case bottom plate as a mounting surface (B).

Fluid control device, decompression device, and compression device

Provided is a suction device that can suppress sound and vibration during use. A suction device includes a flow-passage forming section () having a suction port () from which fluid is sucked, a discharge port () from which the fluid is discharged, and a flow passage () which is sealed from an outside except at the suction port () and the discharge port () and through which the fluid flows, and a piezoelectric driving part () that generates a flow of the fluid in the flow passage (). The piezoelectric driving part () includes a diaphragm () and a piezoelectric element () as a moving part that transmits driving force to the fluid. The moving part is entirely disposed inside the flow passage ().

Suction device

An inhalation device includes a nozzle, a separator, a housing, a battery portion, a circuit board, and a piezoelectric blower. The piezoelectric blower has a suction hole that opens near the center of an upper surface of the piezoelectric blower and a discharge hole that opens at the center of a bottom surface of the piezoelectric blower. The piezoelectric blower is mounted on a first main surface of the circuit board on the side of an upper housing. The circuit board applies a drive voltage to the piezoelectric blower to drive the piezoelectric blower. The circuit board has a through-hole facing the discharge hole. The through-hole overlaps the discharge hole, out of the suction hole and the discharge hole, when the first main surface of the circuit board is viewed from a front side.

Inhalation device

A switching power-supply unit uses a time when a transformer voltage Vt inverts due to a rectifier diode (Ds) entering a non-conducting state as a trigger, and a first switching control circuit (CNT) turns on a first switching element (Q) after a predetermined delay time passes. A second switching control circuit (CNT) turns on a second switching element (Q) using a time when the transformer voltage Vt inverts due to turning off of the first switching element (Q) as a trigger. A third switching control circuit (CNT) turns on a third switching element (Q) using turning off of the second switching element (Q) as a trigger. The first switching control circuit (CNT) determines a period tonof the first switching element (Q) such that a first output voltage Vois set to a predetermined value. The second switching control circuit (CNT) determines an ON-period tonof the second switching element (Q) such that a second output voltage Vois set to a predetermined value. The third switching control circuit (CNT) determines an ON-period tonof the third switching element (Q) such that a third output voltage Vois set to a predetermined value.

Switching power supply

A power supply unit includes a main power-supply circuit and a secondary power-supply circuit which are connected to an alternating current power supply AC. The main power-supply circuit includes a full-wave rectifier and an input current control circuit corresponding to a harmonic current suppression circuit. The input current control circuit includes a resistor as circuit current detection element and a control circuit for controlling a switch element by detecting a current flowing in the resistor. A connection is provided such that a current flowing in a diode as a second rectifying circuit of the secondary power-supply circuit may return to the alternating current power supply through the resistor.

Power supply unit

A switching power supply device includes a primary winding of a transformer that is connected in series to a first switching element, and a secondary winding is provided with a rectifier circuit and an output voltage control circuit arranged to detect an output voltage and feed it back to a control circuit. The control circuit is provided with an on-period control circuit arranged to turn off the first switching element in an on-state based on a feedback signal from the output voltage control circuit and an off-period control circuit arranged to control an off-period thereof by delaying turn-on of the first switching element based on the feedback signal.

Switching power supply device and electronic apparatus

A ripple converter includes a transistor for switching an input direct-current voltage, a choke coil and a smoothing capacitor for smoothing the switched direct-current voltage, a flywheel diode for causing a current to flow through the choke coil when the transistor is turned off, and a comparing unit for controlling the ON/OFF of the transistor according to ripple in an output voltage. In the ripple converter, a waveform converter is provided on a connecting path between an output terminal and a non-inverting input terminal of a comparator in the comparing unit. A result of converting the waveform of the output voltage is compared with a reference voltage, and a result of the comparison is fed back to the transistor.

Ripple converter

A switching power supply apparatus includes a first inductor that is serially connected to a primary winding of a transformer, and a second inductor that is arranged so as to apply a voltage of a capacitor with sine waves obtained by rectifying an AC input voltage for an on-period of a first switching circuit. A diode for preventing the inverse current to the second inductor and a capacitor that is charged by excitation energy charged to the second inductor and applies a voltage to the primary winding for on-period of the first switching circuit. Further, a capacitor is arranged so that the inductor, the primary winding, and a second switching circuit define a closed loop. Switching control circuits control the on-period of a first switching element to control an output voltage Vo, and further control an input voltage Vi by controlling the on-period of a second switching element.

Switching power supply apparatus

A switching power supply apparatus includes first and second switch circuits (S) and (S) including switch devices (Q) and (Q), diodes (D) and (D), and capacitors (Cds) and (Cds), and a transformer (T). A first inductor (Lr) is connected in series with a primary winding (Lp) of the transformer (T), and a second inductor (Li) is arranged so that a voltage of a third capacitor (Ca) is applied during an on-period of the first switch circuit (S). A diode (Di) preventing a reverse current from flowing in the second inductor (Li), and a capacitor (Ci) that is charged by excitation energy stored in the second inductor (Li) and that applies a voltage to the primary winding (Lp) during the on-period of the first switch circuit (S) are further provided. A capacitor (Cr) is further provided so as to define a closed loop together with the inductor (Lr), the primary winding (Lp), and the second switch circuit (S).

A switching power supply includes a control circuit disposed between a feedback winding and a switching device. The control circuit includes an on-period control circuit that, in an operation under a non-low load condition, controls an on-period of the switching device such that the on-period decreases with decreasing load, a minimum on-period setting circuit that disables the on-period control circuit in an operation under a low load condition so that the on-period of the switching device does not become shorter than a predetermined minimum on-period, and an off-period control circuit that controls an off-period of the switching device in the operation under the low load condition such that the off-period increases with decreasing load. As a result, the output voltage is maintained at a constant value in accordance with a feedback signal.

Fly-back converter with constant pulse width and variable duty cycle using a capacitor in control circuit

A switching power supply unit includes a transformer including a primary winding, a secondary winding, and a feedback winding; an input power supply and a first switching element that are connected in series with the primary winding; a control circuit provided between one end of the feedback winding and a control terminal of the first switching element; a rectification circuit connected to the secondary winding; and an output voltage detection circuit for detecting output voltage output from the rectification circuit and for sending a feedback signal to the control circuit. The control circuit includes an on-period control circuit for stabilizing the output voltage by turning off the first switching element in an on-state in accordance with the feedback signal. The control circuit also includes an off-period control circuit for stabilizing the output voltage by delaying turning on of the first switching element in accordance with the feedback signal.

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Muko, Japan

Hiroshi Takemura