A method for operating a circuit for charging and discharging a capacitive actuator. The circuit has a series circuit of first and second power transistors with respective parallel-connected diodes connected between the potentials of a supply voltage source. The node between the power transistors is connected via a coil to the capacitive actuator. For charging the actuator, the first power transistor, which connects the capacitive actuator to the positive potential, is periodically turned on during a prescribed time and turned off when a first prescribed threshold value is reached by the current through the actuator, until a lower threshold value is reached by the current. If the actuator current no longer reaches the first prescribed threshold value then the first power transistor is turned off after a time that corresponds to the maximum value reached by the actuator current.

A method is provided of controlling at least two interacting piezoelectric actuators for commonly displacing an object attached thereto. The method comprises the following steps: a. Step A: applying a first cyclic drive voltage signal with a constant frequency to the first piezoelectric actuator, b. Step B: applying a second cyclic drive voltage signal with a constant frequency to said second piezoelectric actuator, whereby the frequencies of the first and second cyclic drive voltage signals are substantially identical and whereby the frequencies of the first and second cyclic drive voltage signals are substantially oppositely phased, and in which at least in a predetermined time period the cyclic drive voltage signals in step A and B are synchronized such that at least one time phase is comprised in which the drive voltage signals of the first and second piezoelectric actuators have both a gradient of decreasing or increasing the respective drive voltage signal having the same sign or one of these gradients is zero and the other is not zero.

A drive circuit, an electronic device, and a method of controlling a drive circuit that can reduce power consumption. The drive circuit includes: a control circuit that controls application of an AC voltage to a capacitive load; an inductive element which constitutes a closed circuit along with the capacitive load; a diode , which is connected in series to the inductive element between the capacitive load and the inductive element so as to constitute the closed circuit; and a switch element, which is connected in series to the diode between the capacitive load and the inductive element so as to constitute the closed circuit.

The invention relates to a method for activating at least one portion, to be specific a change portion, of an electromechanical element (3), comprising the following steps: providing an electromechanical element, wherein at least the change portion has at least two electrodes, which are spaced apart from one another, and arranged between the electrodes a polycrystalline and ferroelectric or ferroelectric-piezoelectric material with a multiplicity of domains, wherein, in an initial state, at least some of the domains have directions of polarization that are different from one another; generating an electrical field between the electrodes of the change portion by applying an electrical voltage in the form of at least one voltage pulse with a defined amplitude and a defined duration; transforming some of the domains with directions of polarization that are different from one another into a state of the same direction of polarization as a result of the at least one voltage pulse, and thereby producing an increase in the extent of the electromechanical element along a direction of extent V that is defined and persists without the presence of an electrical voltage, or transforming some of the domains with the same direction of polarization into a state with directions of polarization that differ from one another as a result of the at least one voltage pulse, and thereby producing a decrease in the extent of the electromechanical element along the direction of extent V that is defined and persists without the presence of an electrical voltage. The invention also relates to the use of an electromechanical element activated by this method as an adjusting element and to the arrangement of an electromechanical element activated by this method between two elements (1, 2) that are to be moved with respect to one another.

A control device actuates at least one fuel injection valve with a high voltage and a comparatively lower voltage in temporally consecutive phases. The control device has supply connections for supplying energy from a motor vehicle battery. One of the connections is connected to vehicle ground. First output connections provide a positive first output voltage with respect to vehicle ground, the voltage being smaller than or equal to a hazard voltage of 60 volts of direct current according to TRBS2131. Second output connections provide a positive second output voltage with respect to vehicle ground, the voltage being greater than the hazard voltage and smaller than a sum of the first output voltage and the hazard voltage. The positive potentials of the first and second output voltages (U1, U2) are linked together.

A linear actuator has a base, a linear guide coupled to a flat, planar side of the base and extending in a travel length of an object to be moved, a contact plate extending along the flat, planar side of the base, and a carriage. The carriage includes an enclosure formed of an acoustically isolating material, a moving element configured to move along the guide and is coupled to the enclosure, a piezoelectric element including a contact site in physical contact with the contact plate, and a housing elastically holding the piezoelectric element, the housing coupled to the enclosure with no direct contact with the moving element. An electrical power source is in electrical communication with the piezoelectric element, wherein the power source energizes the piezoelectric element to effectuate movement of the carriage along the linear guide via the physical contact between the contact site and the contact plate.

The invention describes a piezo driving circuit, comprising an input at which a temporally variable voltage signal is applied; a piezo interface for connecting terminals of a piezo actuator arrangement with at least one voltage controlled piezo actuator; a sync control circuit realized to detect the phase position of the voltage signal; and an inverter circuit between the input and the piezo interface; whereby the sync control circuit is realized to control the inverter circuit, based on the phase position of the voltage signal, such that a control voltage with a predefined voltage curve is applied at the piezo interface. The invention further describes a method of controlling a piezo actuator arrangement. The invention also describes a piezo actuator configuration comprising a piezo actuator arrangement and an inventive piezo driving circuit. The invention also describes a metering valve comprising the inventive piezo actuator configuration.

A fluid jet dispenser using at least two multilayer piezoelectric actuators is provided. The fluid jet dispenser includes a dispensing head and an electrical driver. The dispensing head includes at least two d.sub.31-mode multilayer piezoelectric actuators, a displacement magnifying element mechanically coupled to the d31-mode multilayer piezoelectric actuators, a piston, and a nozzle. More preferably, the two d31-mode multilayer piezoelectric actuators operate in an anti-phase condition. The electrical driver is electrically coupled to the d31-mode multilayer piezoelectric actuators for displacing the actuators in directions substantially perpendicular to polarization of piezoelectric layers in the d31-mode multilayer piezoelectric actuators in response to charging and discharging of the actuators by the electrical driver, to generate a fast movement of the piston to jet a pressurized fluid out of the nozzle of the dispensing head.

A system for contactless transmission of energy and control signals between a primary device and a secondary device. The primary device has a primary set with at least one primary coil and an electronic supply driver for supplying primary signals to the primary set of primary coils. A secondary device has a secondary set with at least one secondary coil, at least one piezoelectric actuator, and electronic components including a resonant circuit powered by the secondary set. The piezoelectric actuator is powered and controlled through the secondary set of secondary coils and the electronic components.

A stick-slip stage device includes a carriage assembly configured to support a payload, the carriage assembly comprising at least three piezoelectric stick-slip actuators each having one or more contact points. At least two rails are positioned on opposing sides of the carriage assembly and configured to interact with one or more of the contact points to form a guideway for movement of the carriage assembly. A fixed structure connects the at least two rails and is configured to generate a friction force between the at least two rails and one or more of the contact points of the at least three piezoelectric stick-slip actuators. A method of making a stick-slip stage device is also disclosed.