Abstract: A traveling wave ultrasonic motor includes a ring-shaped stator (2) and two groups of electromechanical transducers (3 to 6). Each group comprises a pair of diametrically opposed longitudinal transducers, polarized in opposite directions, disposed perpendicularly to the stator (2). The transducers are in permanent contact with the stator (2) and excited by an alternating current with a &pgr;/2 phase shift between the groups so as to produce a traveling wave-like deformation on the surface of the stator (2). The motor comprises at least one rotor (1) held elastically in contact with the stator (2) for the rotational driving thereof by the traveling wave produced on the stator. The stator is in contact with the rotor only via two or four equal and diametrically opposed segments (9, 10) whose aggregate span is at most equal to a wavelength of the traveling wave produced in the stator.

Abstract: The device is meant to move the solar protection means from a first position, among at least two predetermined positions, toward a second position to adapt to a variation in sunshine. It comprises a logic (6) which breaks down movement from the first to the second position into a minimum of two steps separated by a time interval (T1). A command (STOP) activated by a user during said interval (T1) activates the following step and reduces the interval by a fraction. The activation of an order after the interval (T1) and during the operation of the following step increases the interval (T1) by a fraction. The control device is in this way capable of adapting to the behavior of the user.

Abstract: Power circuit for traveling or standing wave piezo-electric motors comprising a series resonant circuit, a switching element (T1) in parallel with the capacitor C of the resonant circuit and a switching element control (O) ensuring the cyclic closure thereof at a frequency close to the resonant frequency of the resonant circuit. The power circuit includes a transformer (Tr) whose primary constitutes the inductance of the resonant circuit and whose secondary is linked to the piezoelectric exciter, this transformer exhibiting a small magnetic inductance at the primary. An advantage of this power supply is in particular the almost-zero heating of the switching element and low current consumption.

Abstract: The device is meant to move the solar protection means from a first position, among at least two predetermined positions, toward a second position to adapt to a variation in sunshine. It comprises a logic (6) which breaks down movement from the first to the second position into a minimum of two steps separated by a time interval (T1). A command (STOP) activated by a user during said interval (T1) activates the following step and reduces the interval by a fraction. The activation of an order after the interval (T1) and during the operation of the following step increases the interval (T1) by a fraction. The control device is in this way capable of adapting to the behavior of the user.