Abstract: The system makes it possible to control at least one piezoelectric actuator having a capacitive impedance and includes a source of voltage, a control circuit branch in parallel with the source, in which the actuator is connected in series to two electronic switches each having a respective parallel diode; an energy accumulating inductor with one terminal connected between the said switches and the other connected to the voltage source; and an electronic unit operable to control the said controlled switches according to predetermined modes of operation.

Abstract: The system makes it possible to control at least one piezoelectric actuator having a capacitive impedance and includes

Abstract: An electromagnetic actuator, particularly for a valve for controlling the injection of fuel or fuel oil is described and comprises: a fixed permanent magnetic core, and an electrical control winding which is disposed in the magnetic field generated by the core and is movable relative to the core when an electrical current flows through the winding, in which the winding is intended to be connected to a movable member actuable by the device, in a manner such as to bring about movement of the movable member between a rest position and at least one operative position. The winding is also arranged to act on the movable member by exerting a resilient force which can hold the member in the rest position or return the member to the rest position.

Abstract: An actuator for a control valve includes a piezoelectric actuating member for bringing about the movement of a closure member of the valve between an open position and a closure position; the member has a reference portion for connection to a fixed portion of the device and a free portion for connection to the closure member, the free portion being movable relative to the reference portion as a result of mechanical deformations produced in the actuating member by the piezoelectric effect. The reference portion of the actuating member is controllable selectively between a condition in which it is locked in a reference position and is fixed firmly to the fixed portion of the device, and a free condition in which it is movable relative to the fixed portion.

Abstract: An electromagnetic actuator, particularly for a valve for controlling the injection of fuel or fuel oil is described and comprises:

Abstract: An actuator device for a control valve is described and comprises a piezoelectric actuating member for bringing about the movement of a closure member of the valve between an open position and a closure position; the member has a reference portion for connection to a fixed portion of the device and a free portion for connection to the closure member, the free portion being movable relative to the reference portion as a result of mechanical deformations produced in the actuating member by the piezoelectric effect.

Abstract: A control device for a coupling electromagnet in particular for a starter motor for a motor vehicle, operable to regulate the speed of engagement of the pinion of the ring gear in such a way as to avoid stresses wear and noise due to excessive speed of engagement in the initial phase of the starting operation. The device operates in a closed loop with a feedback signal generated by an estimator.

Abstract: A system for automatically controlling a motor vehicle drive unit, which system comprises a hydraulic actuating unit for actuating a control member controlling selection and engagement of the gears on the vehicle transmission; a hydraulic actuator for actuating a control member controlling the clutch; and an electronic control system for processing input signals relative to operating parameters of the drive unit and vehicle in general, and for controlling the actuators to varying degrees of automation. In particular, the control system produces variable control signals for respective porportional solenoid valves controlling the actuators, so as to vary hydraulic supply to the actuators and consequently the actuating force of the same, for simulating operation by a skilled driver; the aforementioned control system also providing, when shifting gear, for controlling the speed of the engine so as to minimize slippage of the clutch.

Abstract: There is disclosed an electromagnetic actuator which is provided with an electromagnet and a movable core which can be attracted by the electromagnet. The electromagnet is formed by a small plate having on its front surface facing the core a plurality of grooves in which are housed respective substantially rectilinear conductor elements. The conductor elements are electrically connected together in such a way as to define on the surface a plurality of elementary magnets disposed alongside one another and having alternately opposite polarity.