Abstract: There is provided a flow rate regulating device including a valve body section having a flat valve body surface, a valve seat section having a flat valve seat surface, a regulation mechanism that moves the valve body section along an axis, and a control unit that controls the regulation mechanism, wherein the regulation mechanism has a stepping motor that rotates a drive shaft about the axis, and a moving member that moves along the axis in response to the rotation of the drive shaft and is coupled to the valve body section, and the control unit controls the stepping motor so that the valve body section moves in a movement range in which the valve body surface and the valve seat surface maintain a non-contact state, in accordance with an excitation signal that changes by a micro step unit obtained by dividing a step by a predetermined division number.

Abstract: To prevent a defect in which a liquid is retained in a vicinity of a valley of a bellows part and particles such as impurities are accumulated. Provided is a valve including a valve element part and a diaphragm part that is coupled to the valve element part. The diaphragm part includes a base, a tip part, and a bellows part that couples between the base and the tip part. A wetted part in contact with the liquid at the tip part is formed in a cylindrical shape extending along a shaft line X. A lower end part of the bellows part is connected to the wetted part in a connection position CP coinciding with an outer peripheral surface of the wetted part. The valley of the bellows part is disposed in the connection position CP.

Abstract: There is provided a flow rate regulating device including a valve body section having a flat valve body surface, a valve seat section having a flat valve seat surface, a regulation mechanism that moves the valve body section along an axis, and a control unit that controls the regulation mechanism, wherein the regulation mechanism has a stepping motor that rotates a drive shaft about the axis, and a moving member that moves along the axis in response to the rotation of the drive shaft and is coupled to the valve body section, and the control unit controls the stepping motor so that the valve body section moves in a movement range in which the valve body surface and the valve seat surface maintain a non-contact state, in accordance with an excitation signal that changes by a micro step unit obtained by dividing a step by a predetermined division number.

Abstract: Provided is a flow control apparatus including a flow passage having a tube pump placed therein, a flow meter placed downstream of the tube pump in the flow direction, the flow meter measuring a flow rate of liquid passing the flow passage, and a flow controller controlling a liquid output of the tube pump so that the flow rate measured by the flow meter matches a target flow rate. The flow passage includes a straight tubular second flow passage that is flexible to be elastically deformed by the pressure of the liquid, the second flow passage being placed downstream of the tube pump in the flow direction, and a third flow passage at which a cross-sectional flow area of the flow passage in a plane orthogonal to the flow direction is smallest, the third flow passage being placed downstream of the second flow passage in the flow direction.

Abstract: To prevent a defect in which a liquid is retained in a vicinity of a valley of a bellows part and particles such as impurities are accumulated. Provided is a valve including a valve element part and a diaphragm part that is coupled to the valve element part. The diaphragm part includes a base, a tip part, and a bellows part that couples between the base and the tip part. A wetted part in contact with the liquid at the tip part is formed in a cylindrical shape extending along a shaft line X. A lower end part of the bellows part is connected to the wetted part in a connection position CP coinciding with an outer peripheral surface of the wetted part. The valley of the bellows part is disposed in the connection position CP.

Abstract: Provided is a thermal flow meter including a measurement tube made of resin having an inlet and an outlet, and an internal flow passage extending along an axis, a sensor substrate having a heating resistance wire and temperature detecting resistance wires formed on a detection surface along the axis, and a reinforcing plate. The sensor substrate is bonded to the measurement tube along the axis with an adhesive, and the reinforcing plate is bonded to the measurement tube along the axis with the adhesive with the internal flow passage interposed between the sensor substrate and the reinforcing plate.

Abstract: Provided is a thermal flow meter including an inlet-side body into which an inlet of a measurement tube is inserted, an outlet-side body into which an outlet of the measurement tube is inserted, an inlet-side nut having internal threads fastened to external threads formed on the inlet-side body, an outlet-side nut having internal threads fastened to external threads formed on the outlet-side body, an inlet-side ferrule of resin being deformed to form a seal area as the inlet-side nut 15a is fastened to the inlet-side body, and an outlet-side ferrule of resin being deformed to form a seal area as the outlet-side nut is fastened to the outlet-side body.

Abstract: There is provided a flow rate adjustment apparatus in which a flow rate measurement mechanism includes: a thermal flowmeter; and a lower casing, a flow rate adjustment mechanism includes: an electric drive mechanism that moves a valve body part; a control board; a valve main body in which a valve chamber, a second flow passage that communicates with a valve hole, and a third flow passage that is connected to an external flow passage have been formed; and an upper casing that houses the electric drive mechanism and the control board thereinside, the flow rate adjustment mechanism is attached to the flow rate measurement mechanism in a state where a clearance communicating with an outside is provided between the lower casing and the valve main body, and in which the thermal flowmeter has a coupling part that couples the second flow passage to a first flow passage.

Abstract: A high-withstand-voltage normally-on transistor and a low-withstand-voltage normally-off transistor are connected in series, and diodes are provided in reverse parallel to the transistor. A gate terminal of the transistor is connected to a source terminal of the transistor, and a gate driving circuit that outputs a control signal to a gate terminal of the transistor is provided. Forward voltage of the diode is made lower than forward voltage of the diode, and an inductance component of a path connecting nodes via the diode is made greater than an inductance component of a path connecting the nodes via the diode. Accordingly, a switching circuit which includes transistors connected in series and in which transient current at a time of turning off is reduced is provided.

Abstract: A power factor correction circuit includes: a coil and MOSFETs that boost an input voltage to generate a boosted voltage; a first capacitor having one end connected to a first output terminal, and the other end connected to an intermediate node; and a second capacitor having one end connected to the intermediate node, and the other end connected to a second output terminal. In a first operation mode, the boosted vol tage is applied to the two ends of the first capacitor when a positive voltage is input, and applied to the two ends of the second capacitor when a negative voltage is input. In a second operation mode, the boosted voltage is applied to two ends of the first and second capacitors connected in series. Thus, there is provided a power factor correction circuit which has a high efficiency and is compatible with an input voltage in a broad range.

Abstract: A highly efficient and low-cost switching power supply device includes a high withstand voltage transistor and a low withstand voltage transistor. When current flows from a second node to a first node, the high withstand voltage transistor turns on and the low withstand voltage transistor turns off, causing current to flow through a built-in diode of the low withstand voltage transistor. Since current does not flow through the parasitic diode of the high withstand voltage transistor, the recovery current is reduced. Furthermore, since a first delay circuit including resistors and a diode is connected to the gate electrode of the high withstand voltage transistor, and a second delay circuit including resistors and a diode is connected to the gate electrode of the low withstand voltage transistor, precise adjustment of the switching speed during switching operation is possible, and losses are reduced.

Abstract: A high-withstand-voltage normally-on transistor and a low-withstand-voltage normally-off transistor are connected in series, and diodes are provided in reverse parallel to the transistor. A gate terminal of the transistor is connected to a source terminal of the transistor, and a gate driving circuit that outputs a control signal to a gate terminal of the transistor is provided. Forward voltage of the diode is made lower than forward voltage of the diode, and an inductance component of a path connecting nodes via the diode is made greater than an inductance component of a path connecting the nodes via the diode. Accordingly, a switching circuit which includes transistors connected in series and in which transient current at a time of turning off is reduced is provided.

Abstract: There is provided a flow rate adjustment apparatus in which a flow rate measurement mechanism includes: a thermal flowmeter; and a lower casing, a flow rate adjustment mechanism includes: an electric drive mechanism that moves a valve body part; a control board; a valve main body in which a valve chamber, a second flow passage that communicates with a valve hole, and a third flow passage that is connected to an external flow passage have been formed; and an upper casing that houses the electric drive mechanism and the control board thereinside, the flow rate adjustment mechanism is attached to the flow rate measurement mechanism in a state where a clearance communicating with an outside is provided between the lower casing and the valve main body, and in which the thermal flowmeter has a coupling part that couples the second flow passage to a first flow passage.

Abstract: A power factor correction circuit includes: a coil and MOSFETs that boost an input voltage to generate a boosted voltage; a first capacitor having one end connected to a first output terminal, and the other end connected to an intermediate node; and a second capacitor having one end connected to the intermediate node, and the other end connected to a second output terminal. In a first operation mode, the boosted vol tage is applied to the two ends of the first capacitor when a positive voltage is input, and applied to the two ends of the second capacitor when a negative voltage is input. In a second operation mode, the boosted voltage is applied to two ends of the first and second capacitors connected in series. Thus, there is provided a power factor correction circuit which has a high efficiency and is compatible with an input voltage in a broad range.

Abstract: There is provided a differential pressure type flowmeter that includes an orifice provided in a main flow channel, a first pressure sensor configured to detect pressure of fluid on an upstream side of the orifice, a second pressure sensor configured to detect pressure of fluid on a downstream side of the orifice, a first pressure introduction flow channel configured to guide the fluid on the upstream side of the orifice to the first pressure sensor, and a second pressure introduction flow channel configured to guide the fluid on the downstream side of the orifice to the second pressure sensor, wherein a flow channel length and a flow channel diameter of the first pressure introduction flow channel coincide with those of the second pressure introduction flow channel, respectively, and a ratio of the flow channel length to the flow channel diameter is not less than 20 times and not more than 30 times.

Abstract: A switching circuit (10) is used as a high-side rectifying unit of a boost chopper. The switching circuit (10) includes a low-breakdown voltage transistor (11), a high-breakdown voltage transistor (13) having a drain connected to a drain of the low-breakdown voltage transistor (11), and a diode (high-speed flyback diode) (15) having a cathode connected to a source of the low-breakdown voltage transistor (11) and an anode connected to a source of the high-breakdown voltage transistor (13). Before the generation of a flyback current by the turning off of a low-side transistor (22), the low-breakdown voltage transistor (11) is turned on while the high-breakdown voltage transistor (13) is kept off. After that, the low-side transistor (22) is turned off.

Abstract: The flow rate adjusting device includes: a valve body disposed so as to open and close the fluid passage; a dial operation part which adjusts minute opening of the valve body in the slow-leaking mechanism; a lock nut part which fixes the adjusting position of the minute opening; and a lock cap which prevents motion of the dial operation part and the lock nut part. The lock cap includes: a first insertion hole into which the substantially cylindrical dial operation part is inserted; a second insertion hole into which a rod protruding upward from the housing is inserted; and an arm part which connects the first insertion hole and the second insertion hole.

Abstract: Provided is a flow control apparatus including a flow passage having a tube pump placed therein, a flow meter placed downstream of the tube pump in the flow direction, the flow meter measuring a flow rate of liquid passing the flow passage, and a flow controller controlling a liquid output of the tube pump so that the flow rate measured by the flow meter matches a target flow rate. The flow passage includes a straight tubular second flow passage that is flexible to be elastically deformed by the pressure of the liquid, the second flow passage being placed downstream of the tube pump in the flow direction, and a third flow passage at which a cross-sectional flow area of the flow passage in a plane orthogonal to the flow direction is smallest, the third flow passage being placed downstream of the second flow passage in the flow direction.

Abstract: Provided is a thermal flow meter including an inlet-side body into which an. inlet of a measurement tube is inserted, an outlet-side body into which an outlet of the measurement tube is inserted, an inlet-side nut having internal threads fastened to external threads formed on the inlet-side body, an outlet-side nut having internal threads fastened to external threads formed on the outlet-side body, an inlet-side ferrule of resin being deformed to form a seal area as the inlet-side nut 15a is fastened to the inlet-side body, and an outlet-side ferrule of resin being deformed to form a seal area as the outlet-side nut is fastened to the outlet-side body.

Abstract: Provided is a thermal flow meter including a measurement tube made of resin having an inlet and an outlet, and an internal flow passage extending along an axis, a sensor substrate having a heating resistance wire and temperature detecting resistance wires formed on a detection surface along the axis, and a reinforcing plate. The sensor substrate is bonded to the measurement tube along the axis with an adhesive, and the reinforcing plate is bonded to the measurement tube along the axis with the adhesive with the internal flow passage interposed between the sensor substrate and the reinforcing plate.