Abstract: A pump device includes a piezoelectric pump, a piezoelectric pump, and a driving circuit. The piezoelectric pump is driven at a first frequency when singly driven. The piezoelectric pump is driven at a second frequency when singly driven. The driving circuit drives the piezoelectric pump and the piezoelectric pump at the same driving frequency.

Abstract: A pump device including a first piezoelectric pump, a second piezoelectric pump connected in series with the first piezoelectric pump on a downstream side of the first piezoelectric pump, a drive unit configured to supply AC power as input power to each of the first piezoelectric pump and the second piezoelectric pump, a control unit configured to control input power to the first piezoelectric pump and the second piezoelectric pump, and a power supply unit configured to supply power to the drive unit, in which the control unit sets input power of the second piezoelectric pump to be larger than input power of the first piezoelectric pump.

Abstract: A mixed-fluid delivery device includes a piezoelectric pump that includes a piezoelectric vibrator having a piezoelectric element and a vibrating plate and a pump cabinet and discharges a fluid, and a case body including a pump housing chamber, a liquid reservoir portion, a mixing portion that generates a mixed fluid, a nozzle portion through which the gas discharged from the piezoelectric pump is ejected to the mixing portion, and a conducting portion that conducts a liquid toward the mixing portion. The case body has a reflux path through which a residual liquid that remains in the mixing portion without being delivered to the outside is returned to the liquid reservoir portion. The reflux path is provided so as to be in contact with at least a portion of the pump cabinet.

Abstract: The present disclosure provides a fluid control device and an output adjustment method with which the output of a pump can be easily adjusted even if an atmospheric pressure changes. A pump unit includes a first flow path, a u piezoelectric pump, a d piezoelectric pump, a second flow path, a third flow path, a control circuit capable of controlling driving of the u piezoelectric pump and the d piezoelectric pump, and a current sensor for detecting respective currents of the u piezoelectric pump and the d piezoelectric pump. The control circuit is capable of adjusting at least one of the output of the u piezoelectric pump and the output of the d piezoelectric pump on the basis of a difference (Iu?Id) between a current Iu of the u piezoelectric pump and a current Id of the d piezoelectric pump detected by the current sensor.

Abstract: A fluid control apparatus includes a piezoelectric pump, a pressure vessel, an input unit, a drive control unit, and a driving circuit. The piezoelectric pump has a pump chamber whose volume fluctuates due to displacement of a piezoelectric element, a valve chamber communicated with the pump chamber and has a valve diaphragm, a pump chamber opening that allows the pump chamber to be communicated with an outside of the pump chamber, and a valve chamber opening that allows the valve chamber communicate with an outside of the valve chamber. The pressure vessel is communicated with the valve chamber. The driving circuit drives the piezoelectric element upon application of a driving power-supply voltage from the drive control unit. The drive control unit adjusts the driving power-supply voltage or a driving current corresponding to the driving power-supply voltage in accordance with a vibration state of the valve diaphragm.

Abstract: A pump unit (100) includes a plurality of piezoelectric pumps (1), a flow path-defining member (50), and a heat-dissipating part (60). The plurality of piezoelectric pumps (1) each include a first flow path for sucking and discharging of fluid. The flow path-defining member (50) includes a second flow path for connection to the first flow paths in the plurality of piezoelectric pumps (1). Heat generated in the plurality of piezoelectric pumps (1) is dissipated through the heat-dissipating part (60). The heat-dissipating part (60) is disposed between the flow path-defining member (50) and each of the plurality of piezoelectric pumps (1). The heat-dissipating part (60) has through-holes through which the first flow paths are connected to the second flow path.

Abstract: Provided are a fluid control device capable of operating a piezoelectric pump even in a case where a low discharge pressure or a slow pressurization speed is required and a sphygmomanometer including the fluid control device. A fluid control device includes a piezoelectric pump that includes a piezoelectric element, a self-excited circuit that performs, upon application of a driving power source voltage thereto, self-excited oscillation to drive the piezoelectric element, a switch that interrupts the driving power source voltage for the self-excited circuit, and a control circuit that changes an on duty ratio of the self-excited circuit by switching between states of the switch at a predetermined switching frequency and a predetermined on duty ratio.

Abstract: A pressure-controlling device (10) includes a pump (21), a connection pipe (30), a first valve (41), and a second valve (42). The pump (21) has an inlet port (211) and an outlet port (212). The connection pipe (30) has a first end in communication with the outlet port (212), and a second end in communication with the inlet port (211) and that has a first space (31) that contains the first end, a second space (32) that contains the second end, and a third space (33) that is located between the first space (31) and the second space (32).

Abstract: A piezoelectric element driving circuit includes a boosting circuit, a driving circuit, a waveform shaping circuit, and a computing circuit. The driving circuit includes a differential amplifier circuit with an LPF, an amplifier circuit with a BPF, an inverter, a resistor, and a comparator. The driving circuit applies a driving signal to a piezoelectric element of a piezoelectric pump. The waveform shaping circuit extracts a voltage signal from the driving circuit. On the basis of the voltage signal, the waveform shaping circuit and the computing circuit determine a voltage value corresponding to driving current flowing through the piezoelectric element. The computing circuit outputs a control signal to the boosting circuit on the basis of the voltage value. The boosting circuit sets the value of a DC supply voltage on the basis of the control signal, and outputs the DC supply voltage.

Abstract: A piezoelectric element drive circuit includes a piezoelectric element driven at a predetermined frequency and having a resonant frequency of (2n+1) times the predetermined frequency (n is a predetermined natural number), and a drive voltage generator that has a first output terminal connected to a first terminal of the piezoelectric element and a second output terminal connected to a second terminal of the piezoelectric element. When the piezoelectric element is driven, a waveform of potential difference between the first output terminal and the second output terminal is a step wave which transitions while taking an intermediate potential. A time length for which the potential difference is the intermediate potential is around (t2?t1)/(2n+1) in a period of time from time t1 at which the potential difference falls to the intermediate potential to time t2 at which the potential difference falls to the intermediate potential subsequently.

Abstract: A fluid control device includes a piezoelectric pump, a piezoelectric pump, a container, and a control unit. The piezoelectric pumps and are connected in series. The piezoelectric pump is an upstream-side pump, and the piezoelectric pump is a downstream-side pump. The control unit controls driving of the piezoelectric pumps. The control unit makes the driving start timing of the piezoelectric pump on an upstream side earlier than the driving start timing of the piezoelectric pump on a downstream side.

Abstract: A fluid control device includes a piezoelectric pump, a piezoelectric pump, a valve, and a container. The piezoelectric pump and the piezoelectric pump repeat the operation and the stop in accordance with a drive control cycle. The valve starts a control to close at the start timing of one cycle of the drive control cycle and starts a control to open at the stop of the piezoelectric pump and the piezoelectric pump. The time from the start timing of one cycle of the drive control cycle to the time at which the piezoelectric pump on the upstream side pump reaches a normal operation drive voltage is longer than the time from the start timing to the time at which the piezoelectric pump on the downstream side reaches a normal operation drive voltage.

Abstract: A fluid control device includes a piezoelectric pump having a piezoelectric element, a driving circuit that receives a driving power supply voltage applied thereto and drives the piezoelectric element, and a startup circuit disposed between the driving circuit and an input terminal for a power supply voltage. The startup circuit increases the driving power supply voltage to a voltage (V1) lower than a constant voltage (Vc) in a first stage (P1) after startup, maintains or decreases the driving power supply voltage in a second stage (P2) following the first stage (P1), and increases the driving power supply voltage to the constant voltage (Vc) in a third stage (P3) following the second stage (P2).

Abstract: A fluid control device includes a piezoelectric pump having a piezoelectric element, a driving circuit that receives a driving power supply voltage applied thereto and drives the piezoelectric element, and a startup circuit disposed between the driving circuit and an input terminal for a power supply voltage. The startup circuit increases the driving power supply voltage to a voltage (V1) lower than a constant voltage (Vc) in a first stage (P1) after startup, maintains or decreases the driving power supply voltage in a second stage (P2) following the first stage (P1), and increases the driving power supply voltage to the constant voltage (Vc) in a third stage (P3) following the second stage (P2).

Abstract: A driving device includes a voltage regulation circuit, a driving signal generation circuit, a current limiting circuit, and a voltage control circuit. The voltage regulation circuit regulates a power supply voltage and outputs a driving voltage. The driving signal generation circuit generates a driving signal to a piezoelectric element of a piezoelectric pump by using the driving voltage. The current limiting circuit limits a driving current corresponding to the driving voltage to a specified current or less, and generates a current control voltage. The voltage control circuit limits the driving voltage based on the current control voltage.

Abstract: A pump device (1) includes a piezoelectric pump (10) and an outer casing (70). The piezoelectric pump (10) includes a pump casing having inlets (400) and an outlet (520), a vibration plate (31) disposed inside the pump casing and dividing an internal space (500) of the pump casing into a first space (501) on a side near the inlets (400) and a second space (502) on a side near the outlet, and a piezoelectric element (20) disposed on the vibration plate (31). The outer casing (70) forms a flow path composed of an internal space (700) that allows communication between an external inlet (701), which communicates with the outside, and the inlets (400). The flow path has a part that is parallel to an outer main surface (40op) of the pump casing in which the inlets (400) are formed, the part being located outside the outer main surface (40op).

Abstract: A pump device including a first piezoelectric pump, a second piezoelectric pump connected in series with the first piezoelectric pump on a downstream side of the first piezoelectric pump, a drive unit configured to supply AC power as input power to each of the first piezoelectric pump and the second piezoelectric pump, a control unit configured to control input power to the first piezoelectric pump and the second piezoelectric pump, and a power supply unit configured to supply power to the drive unit, in which the control unit sets input power of the second piezoelectric pump to be larger than input power of the first piezoelectric pump.

Abstract: An atomizer includes a first piezoelectric pump, a second piezoelectric pump, a first flow path connected to the first piezoelectric pump, a second flow path connected to the second piezoelectric pump and merged with the first flow path, a third flow path connected to a merging portion of the first flow path and the second flow path, the third flow path having a first end and a second end, a liquid storage portion, and a nozzle including a gas supply flow path connected to the second end of the third flow path, a liquid supply flow path connected to the liquid storage portion, and a blow-out port, wherein the third flow path has a bent portion between the first end and the second end.

Abstract: A fluid control device (10) includes a container (13), a pump (11), a solenoid valve (12), and a capacitor. The pump (11) is driven by a main power source, and is capable of pressurizing or depressurizing the inside of the container (13). A suction port and a discharge port of the pump (11) internally communicate with each other. The solenoid valve (12) is connected at both ends thereof to the container (13) and the pump (11). If the voltage of the main power source is reduced or lost, the solenoid valve (12) releases pressure in the container (13) by being driven by the power stored in the capacitor or secondary battery.

Abstract: A piezoelectric element drive circuit includes a piezoelectric element driven at a predetermined frequency and having a resonant frequency of (2n+1) times the predetermined frequency (n is a predetermined natural number), and a drive voltage generator that has a first output terminal connected to a first terminal of the piezoelectric element and a second output terminal connected to a second terminal of the piezoelectric element. When the piezoelectric element is driven, a waveform of potential difference between the first output terminal and the second output terminal is a step wave which transitions while taking an intermediate potential. A time length for which the potential difference is the intermediate potential is around (t2?t1)/(2n+1) in a period of time from time t1 at which the potential difference falls to the intermediate potential to time t2 at which the potential difference falls to the intermediate potential subsequently.