A cooling system and method for using the cooling system are described. The cooling system includes an array of cooling elements and a controller. The array of cooling elements corresponds to regions of the heat-generating structure where heat is generated in response to operation of the semiconductor. The controller is configured to activate portions of the array of cooling elements based on a determination that operation of the heat-generating structure is likely to generate heat in a given region of the heat-generating structure.

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.

An aircraft assembly having: a first part; a second part, the second part being movably mounted with respect to the first part; an electro-hydraulic actuator coupled between the second part and a first anchor point, the actuator comprising a cylinder defining a bore and a piston and rod assembly slidably mounted within the bore and an active chamber within which an increase in fluid pressure causes the actuator to change during a first phase between first and second extension states to move the second part relative to the first part. The electro-hydraulic actuator further includes a hydraulic fluid supply circuit comprising a piezo-electric pump operable to supply pressurised fluid to the active chamber to change the actuator between first and second extension states.

A system for cooling a mobile phone and method for using the system are described. The system includes an active piezoelectric cooling system, a controller and an interface. The active piezoelectric cooling system is configured to be disposed in a rear portion of the mobile phone distal from a front screen of the mobile phone. The controller is configured to activate the active piezoelectric cooling system in response to heat generated by heat-generating structures of the mobile phone. The interface is configured to receive power from a mobile phone power source when the active piezoelectric cooling system is activated.

A system for cooling a mobile phone and method for using the system are described. The system includes an active piezoelectric cooling system, a controller and an interface. The active piezoelectric cooling system is configured to be disposed in a rear portion of the mobile phone distal from a front screen of the mobile phone. The controller is configured to activate the active piezoelectric cooling system in response to heat generated by heat-generating structures of the mobile phone. The interface is configured to receive power from a mobile phone power source when the active piezoelectric cooling system is activated.

A fluid control apparatus includes a valve and a pump. The valve has a valve chamber. The first main plate has a first aperture through which the valve chamber communicates with the outside, and the second main plate has a second aperture through which the valve chamber communicates with the outside. The valve further includes a valve diaphragm disposed inside the valve chamber. The valve diaphragm is configured to switch the communication state. The pump includes a piezoelectric device. The pump has a pump chamber. The pump chamber communicates with the valve chamber through the second aperture. In addition, in flexural vibration of the vibration unit, a frequency coefficient of the first main plate is greater than a frequency coefficient of the second main plate.

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.

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).

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).

A miniature piezoelectric pump module is provided and includes a piezoelectric pump, a microprocessor, a driving component and a feedback circuit. The piezoelectric pump includes two electrodes and a piezoelectric element and has the best efficiency while operating under an ideal operating voltage. The driving component is electrically connected to the microprocessor and the piezoelectric pump and includes a transform element and an inverting element. The transform element outputs an effective operating voltage to the piezoelectric pump. The inverting element controls the two electrodes to receive the effective operating voltage or to be grounded. The piezoelectric element is subjected to deformation for transporting fluid due to piezoelectric effect. The feedback circuit generates a feedback voltage according to the effective operating voltage. The microprocessor adjusts the modulation signal according to the feedback voltage for adjusting the effective operating voltage outputted by the transform element to approach the ideal operating voltage.