Abstract: In order to provide a piezo valve in which it is possible to accurately predict the remaining lifespan of a piezo actuator, there are provided a valve seat, a valve body that is able to move between a fully closed position in contact with the valve seat and a fully open position, a piezo actuator that drives the valve body, a drive circuit that receives an input signal, and outputs to the piezo actuator a corresponding drive voltage, and a leakage current detector that, when the drive circuit outputs a voltage equal to or greater than a maximum rated voltage that drives the valve body to the fully closed/open position, detects leakage current from the piezo actuator. When the leakage current is detected or in a state immediately prior to detection, a fluid is flowing between the valve seat and the valve body.

Abstract: A fluid control valve can suppress heat generation when discharging charges from a piezo actuator for contraction and reduce energy necessary to drive the piezo actuator. The fluid control valve includes a piezo actuator and a drive circuit connected to the piezo actuator is adapted so that the drive circuit includes: a flyback transformer including a primary side coil connected to a DC power supply DV and a secondary side coil connected to the piezo actuator; a charge switch that is connected to the primary side coil and switched from on to off when the piezo actuator charges; a discharge switch that is connected to the secondary side coil and switched from off to on when the piezo actuator discharges; and a regenerative capacitor that is connected to the primary side coil and into which electric energy due to the discharge of the piezo actuator is regenerated.

Abstract: In order to provide a piezo valve in which it is possible to accurately predict the remaining lifespan of a piezo actuator, there are provided a valve seat, a valve body that is able to move between a fully closed position in contact with the valve seat and a fully open position, a piezo actuator that drives the valve body, a drive circuit that receives an input signal, and outputs to the piezo actuator a corresponding drive voltage, and a leakage current detector that, when the drive circuit outputs a voltage equal to or greater than a maximum rated voltage that drives the valve body to the fully closed/open position, detects leakage current from the piezo actuator. When the leakage current is detected or in a state immediately prior to detection, a fluid is flowing between the valve seat and the valve body.

Abstract: A fluid control valve can suppress heat generation when discharging charges from a piezo actuator for contraction and reduce energy necessary to drive the piezo actuator. The fluid control valve includes a piezo actuator and a drive circuit connected to the piezo actuator is adapted so that the drive circuit includes: a flyback transformer including a primary side coil connected to a DC power supply DV and a secondary side coil connected to the piezo actuator; a charge switch that is connected to the primary side coil and switched from on to off when the piezo actuator charges; a discharge switch that is connected to the secondary side coil and switched from off to on when the piezo actuator discharges; and a regenerative capacitor that is connected to the primary side coil and into which electric energy due to the discharge of the piezo actuator is regenerated.