Abstract:
Provided is a circuit for driving a magnetostrictive device including: a high voltage interrupting circuit section (C 2 ,R 1 ) for interrupting an instantaneously leaking high voltage depending on the switching operation of a power switch (SW); a voltage storage section (C 1 ) for rectifying an input voltage for a half of the positive cycle and storing it; a switching circuit section (Q 1 ) for supplying the voltage stored in the voltage storage section to the magnetostrictive device; and a voltage discharging circuit section (R 5 ) for discharge the voltage remaining in the voltage storage section when the power is interrupted.
Abstract:
The invention relates to devices that produce displacements and/or forces (defined as actuators), when a magnetic field source(s) is (are) placed in such a way that the resulting magnetic field is of suitable strength and orientation in relation to the actuating element made from a Magneto-Mechanical Adaptive (MMA) material, so as to produce the desired displacement of the MMA element; or to devices that dampen mechanical vibrations by absorbing the vibration energy into an MMA element and/or by converting the vibration energy into electric power in the device and/or senses displacement, velocity or acceleration. The electric energy can be dissipated to heat or led out from the device. In the latter case, the device works as a power generator. The principle of using the devices as sensors is also described. The MMA material here is defined as a material whose dimensions change when a magnetic field or stress is applied to it, based on twin boundary or austenite-martensite phase boundary motion or magnetostriction.
Abstract:
Esta invención se refiere a un generador sónico y/o ultrasónico para emisión en aire con una capacidad de potencia y unas características de radiación que permiten obtener de forma segura y controlada, los niveles de presión acústica necesarios (>170dB ref. 2.10- 4 μbar) para la rotura mecánica de las burbujas de alta consistencia que constituyen las espumas industriales.
Abstract:
A method of generating acoustic oscillations based on the shock excitation of a magnetostrictive converter with a pulse electric signal. The electric signal is generated in the form of unidirectional half-cycles of cosinusoidal voltage having the length of one to two half-cycles of acoustic oscillations of the loaded converter. The frequency of the electric pulses is chosen equal or multiple to the frequency of the acoustic oscillations. A source of acoustic oscillations comprises a power supply unit (7), a pulse frequency unit (10) and an energy storage capacitor (6) to the plates of which the exciting winding (2) of a magnetostrictive converter (1) is connected through the power circuit of a commutating element (5). The source comprises as well an additional exciting winding (3) placed also on the magnetostrictive converter (1) and concordantly to the winding (2), an additional commutating element (8) and a unit (9) for control of the commutating elements. The additional winding (3) is connected to the plates of the capacitor (6) through the power circuit of the commutating element (8) and through the power supply unit (7), whereas the output of the pulse frequency unit (10) is connected to the input of the unit (9) for control of the commutating elements, the outputs of that unit being connected correspondingly to the control circuits of the commutating elements (5 and 8). The source of acoustic oscillations is intended preferably for ultrasound cleaning of heat exchangers from sediments.
Abstract:
This invention refers to a sonic and/or ultrasonic generator for emission in air with a power capacity and certain radiation characteristics which permit the necessary acoustic levels (> 170 dB ref. 2.10 4 µbar) to be obtained in a way that is safe and controlled for the mechanical breakage of high consistency bubbles constituting industrial foams.