Magnetoelectric current-voltage transducer with frequency doubling
SUBSTANCE: transducer is a structure of a capacitor, the plates of which are made of magnetostrictive metal and mechanically connected to a piezoelectric plate inside and to an inductance coil wound on it, and of a magnetic core, made in the form of two U-shaped plates closely adjacent to the magnetostrictive plates, that ensures the magnetic flux closure. The input signal is the current of the inductance coil, and the output signal is taken from the capacitor plates.
EFFECT: to ensure the transducer's operation, it is not required to create a bias field, and it contains a magnetic core that ensures the magnetic flux closure, which leads to a reduction in energy losses.
SUBSTANCE: invention relates to devices for conversion of frequency driven by a network and may be used in plants, where frequency control is required. Two semiconductor units of a three-phase bridge module are made from semiconductor elements, besides, semiconductor elements of one semiconductor unit are combined and connected to the start of the load, and semiconductor elements of the other semiconductor unit are combined and connected to the end of the load. Semiconductor elements of one semiconductor unit and semiconductor elements of the other semiconductor unit are connected in pairs, and these pairs are connected to appropriate phases of a three-phase source of AC voltage. Semiconductor elements are transistors, which send current in a key mode from the emitter to the collector and from the collector to the emitter. Collectors of transistors of one semiconductor unit of the three-phase bridge module are combined and connected to the start of the load, and collectors of transistors of the other semiconductor unit of the three-phase bridge module are combined and connected to the end of the load. Emitters of transistor of one and other semiconductor units of the three-phase bridge module are combined in pairs and are connected to appropriate phases of the three-phase source of AC voltage.
EFFECT: generation of sign-changing voltage of different frequency on a load.
SUBSTANCE: invention relates to electrical equipment and is designed for use in an electric drive for control of speed of induction motors. Each of three semiconductor modules is connected to a three-phase AC network. Semiconductor transistors are used in each of three semiconductor modules. In the first semiconductor module collectors of the first, second and third transistors are combined and connected with a common point to the start of the first winding of the three-phase induction motor, emitters of the first, second and third transistors are connected to appropriate windings of the three-phase transformer. In the second semiconductor module collectors of the fourth, fifth and sixth transistors are combined and connected to the start of the second winding of the three-phase induction motor, emitters of the fourth, fifth and sixth transistors are connected to appropriate windings of the three-phase transformer. In the third semiconductor module collectors of the seventh, eighth and ninth transistors are combined and connected to the start of the third winding of the three-phase induction motor, emitters of the seventh, eighth and ninth transistors are connected to appropriate windings of the three-phase transformer. Ends of the first, second and third windings of the three-phase induction motor are combined and connected to zero of the transformer.
EFFECT: higher reliability, reduced dimensions, and also simplified control system due to reduced number of switching semiconductor equipment.
SUBSTANCE: invention relates to conversion equipment and is designed for use in electric AC drives controlled by optoelectronic insulators, and sources of secondary power supply. In the frequency converter with an intermediate link of DC and a power unit, representing a bridge circuit on transistor keys, apart from protection of these keys against failure in case of throughput current in a bridge arm and in transition processes of converter disconnection, an additional protection is introduced for control of a bridge inverter in transition processes of converter elements supply. The additional protection consists in the fact that control of the bridge inverter is provided only in the case, if voltage of converter elements supply is more than 4.5 V. Otherwise, control of the bridge inverter will be blocked.
EFFECT: introduction of additional protection of bridge inverter control in transition processes of converter elements supply.
SUBSTANCE: frequency-pulse duration alternating voltage controller has an adder, an integrator, a relay element, comparators, dynamic D flip-flops, switch elements (thyristors), load resistors connected in a star circuit with a neutral terminal, a setting signal source and a three-phase voltage source. Said alternating current controller includes three dynamic D flip-flops, which enable to generate 'packets' of sinusoidal voltage across the load with a whole number of periods of mains voltage.
EFFECT: high energy efficiency.
FIELD: radio engineering.
SUBSTANCE: by means of 4 similar balance (double balance) mixers there formed in parallel are 4 products of quadratures of input and heterodyne signals: (cosinpĚcoshet); (sininpĚsinhet); (sininpĚcoshet); (cosinpĚsinhet). Both input signal and heterodyne signal is pre-split into quadrature components - cosine (advanced) and sine (retarded); each component of input signal is multiplied by each component of heterodyne and in compliance with trigonometry formulae for cosine and sine of sum and difference of two angles thee formed are cosine and sine quadrature signal components of intermediate frequency. Essence of the device consists in the fact that phase splitters of input signal and heterodyne signal into quadrature projections, cosine and sine ones, are introduced to it; four multipliers - balance mixers are used as mixer, which are loaded onto the first (RH1) and the second (RH2) load resistors and connections between them.
EFFECT: improving interference immunity and simplifying frequency division of GLONASS signals.
2 cl, 3 dwg
SUBSTANCE: circuit of three-phase frequency converter comprises source of ua, ub, uc setting signals (1), the first group of summators (2-4), the second group of summators (5-1), the first-third amplifiers (8-10) generator of correction signal (11) generator of linearly varying signal (12) the first-third comparators (13-15) the first-third inverters (16-18) driver (19) unit of power switches (20), unit of three-phase load (21), unit of voltage sensors (22). Due to arrangement of correction signal generator (11) with the possibility to implement function with limitation of values ua+uk, ub+uk, uc+uk within the limits of linearly varying signal, three-phase frequency converter may operate with optimal power parameters, i.e. with reduction of losses capacity in load due to pulse-width modulation at balanced system of master voltages and preservation of maximum linear zone of output voltage without complication of three-phase frequency converter.
EFFECT: minimised capacity of losses in three-phase load connected to pulse-width modulation with preservation of maximum linear zone of output voltage.
FIELD: electrical engineering; ac consists.
SUBSTANCE: proposed device designed to control speed of fan driven by three-phase induction motor has traction transformer 1 with its primary winding 2 connected to supply mains 3, auxiliary winding 4 with terminal and intermediate leads, frequency converter built around two pairs of thyristors connected in parallel opposition, and control unit 9 whose outputs are connected to control inputs of thyristors. First pair of thyristors is connected to one terminal lead and second one, to other terminal lead of auxiliary winding. to terminal leads of auxiliary winding. Three-phase induction motor 10 is characterized in enhanced number of low-speed steps; its first phase lead is connected to loose lead of first pair of thyristors, its second phase lead, to loose lead of second pair of thyristors, and third phase lead, to intermediate lead of auxiliary winding.
EFFECT: enlarged range of fan capacity regulation by load current, reduced cost of locomotive auxiliary power.
1 cl, 1 dwg
FIELD: electrical engineering; ac consists.
SUBSTANCE: proposed device designed to regulate capacity of fans driven by three-phase induction motors has traction transformer 1 with its primary winding 2 connected to supply mains, auxiliary winding 4 with terminal and intermediate leads, frequency converter built around four thyristors, and control unit 9 whose outputs are connected to control inputs of thyristors. The latter are interconnected in two groups, each having two series-connected thyristors, and are connected to terminal leads of auxiliary winding. One thyristor group is connected to winding cumulatively and other group, differentially. Three-phase induction motor 10 is characterized in enhanced number of low-speed steps; its first phase lead is connected to common point of first-group thyristors, its second phase lead, to common point of second-group thyristors, and third phase lead, to intermediate lead of auxiliary winding.
EFFECT: enlarged range of fan capacity regulation by load current, reduced cost of locomotive auxiliary power.
1 cl, 1 dwg
FIELD: electric engineering, in particular, engineering of frequency transformers, in particular, engineering of transformer type multipliers, for example, doublers, possible use for powering high speed drives of wood-processing industry, reducer-less centrifuges, for induction heating of large metallic blocks and the like.
SUBSTANCE: frequency doubler contains transformer, on each rod of which four primary windings are positioned, combined in two pairs. Each pair of primary windings is closed on pair of synchronously enabled transistors, working in such a wag, that starting portion of powering voltage sinusoid is utilized. Common connection points of transistors of first and second pairs and windings of second pair are connected in accordance to direct series of phases alternation to input phase clamps. Common connection point of windings of first pair is connected to zero input clamp.
EFFECT: improved power coefficient due to use of starting portion of sinusoid of powering voltage in process of generation of EMF of doubled frequency in windings of transformer.
FIELD: electrical engineering, applicable for frequency conversion of multiphase alternating current.
SUBSTANCE: the method is based on the fact that the power switches of an active rectifier and self-excited inverter are controlled with the aid of two control channels, in this case the standard modulating signal defining the switching function in one channel is subjected in succession to phase and amplitude premodulations, pulse-length modulation and phase modulation, in the other channel - it is subjected to amplitude and adapting premodulation an in pulse-length modulation with the use of a high-frequency reference signal.
EFFECT: eliminated distortions of the useful components of output voltages.
6 cl, 6 dwg
SUBSTANCE: ultrasound piezoelectric converter comprises a body with a damping layer applied to its inner surface and inside the body there is a prism, a damper connected to the body and a piezoelectric cell installed at the prism and connected to the damper. At the prism base there are additional plane-parallel rectangular metal plates with spacers between them. The metal plates have different height and form a graded pyramid, and dimensions of the plane-parallel rectangular metal plates are selected on the basis of certain conditions.
EFFECT: potential input of rectangular ultrasonic waves to an element of a metal structure at angles values close to 90 degrees without the use of a complicated control system for time delay in voltage pulses.
3 cl, 2 dwg
SUBSTANCE: invention relates to piezoelectronics. Essence of the invention: the working body of the high-voltage generator is formed by inertial mass and a package of the plates of polarised composite ferroelectric materials with high values of piezoelectric voltage coefficient and compressive strength pre-set for each plate. The distances between the conducting surfaces applied on the plates is set such that their values multiplied by values of mechanical stress and piezoelectric stress coefficient be identical to each plate in the package. The method comprises the manufacture of each batch of the plates polarised composite ferroelectric materials by consecutive execution of the following operations: preparation of moulding powder of the synthesised material, preparation of mix of moulding powder of the synthesised material and pore agent, moulding from mix of work-pieces and their high-temperature processing by an agglomeration method, machining, metallisation, polarisation and measurement of parameters. The pre-set compressive strength for each batch of plates is achieved by a porosity variation due to change of concentration of pore agent in the plate.
EFFECT: conversion of mechanical compression stress to electric energy without explosive, reduction of time of formation and increase of occurring electric charge in unit of volume of the working body at high values of potential difference.
2 cl, 2 dwg, 2 ex
SUBSTANCE: shock pick-up includes piezoelectric working medium and recording system. The working medium is made of piezoceramics with cohesion of 3-0 with maximum values of voltage index g33. At that the pick-up has an additional a resonating piezoelectric cell for calibration, which surface is coupled to the working medium surface.
EFFECT: increasing sensitivity of the piezoelectric pick-up at minimum weight, potential calibration and functional check in zero gravity conditions.
4 cl, 3 dwg, 1 tbl
SUBSTANCE: invention relates to making magnetoelectric converters used as a base for magnetic field sensors, microwave electronic devices, for magnetoelectric information recording technology and for electromagnetic energy and vibration energy storages. The method involves forming a stack of alternating magnetostrictor and piezoceramic layers. Said stack is formed in three steps: first, electroconductive contacts are deposited on the entire surface of magnetostrictors; all surfaces of magnetostrictors and piezoceramic, except end surfaces, are coated with a layer of electroconductive epoxy adhesive, after which a stack of alternating magnetostrictor and piezoceramic layers is formed. The layers are joined by pressing at temperature of 60-100░C and excess pressure of (1.3-2.6)Ě105 Pa. The multilayer ceramic heterostructure contains 9-11 magnetostrictor and piezoceramic layers. The piezoeceramic layer has thickness of 0.10-0.13 mm and the magnetostrictor layer has thickness of 0.25-0.30 mm.
EFFECT: low power consumption and high sensitivity.
2 cl, 2 tbl, 4 dwg
SUBSTANCE: piezoelectric multilayer component has a stack (1) of piezoceramic layers (2) and electrode layers (3) arranged one above the other. At least one piezoceramic layer is printed with a layer (4) structured according to a predefined configuration in a piezoelectrically inactive zone of the stack. The structured layer has at least one connecting element (4a) by which piezoceramic layers which are adjacent in the stacking direction are mechanically connected to each other with a first strength. The structured layer has interspaces (4b) filled at least in part with piezoceramic material of the adjacent piezoceramic layers. The adjacent piezoceramic layers in the interspaces are mechanically connected to each other with a second strength, which is less than the first strength.
EFFECT: longer extension and period of operation.
15 cl, 1 tbl, 4 dwg
SUBSTANCE: acoustic line is made in form of a rectangular prism. Further, optically antireflecting coatings are deposited via vacuum deposition onto the faces of the rectangular prism. A first adhesive layer is then deposited on one of the faces of the rectangular prism by vacuum deposition. Using vacuum deposition, a first gold layer is deposited on said first adhesive layer. Further, a first indium layer is deposited on said first gold layer by vacuum deposition. Also, using vacuum deposition, a second adhesive layer is deposited on one of the larger faces of each of two plates made from lithium niobate of the (Y+36░)-section. Using vacuum deposition, a second gold layer is then deposited on said second adhesive layer. Using vacuum deposition, a second indium layer is deposited on said second gold layer. The acoustic line is the joined with the lithium niobate plates by pressing the lithium niobate plates with the pressure of each lithium niobate plate of the second indium layer to the corresponding first indium layer. Each of the lithium niobate plates is then ground off to the required thickness which corresponds to the operating frequency band. Using vacuum deposition, a third adhesive layer is deposited on each free large face of each lithium niobate plate. A third gold layer is then deposited on said third adhesive layer via vacuum deposition. The method is characterised by that the acoustic line material used is a TeO2 monocrystal, wherein the faces of the rectangular prism are directed perpendicular to the crystallographic direction , , , and deposition of optically antireflecting coatings is carried out on faces of the rectangular prism which are perpendicular to the the crystallographic direction ; when joining the lithium niobate plates to the acoustic line, the projections of polar axes of the lithium niobate plates are directed onto the same plates in opposite sides; the first adhesive layer is deposited on one of the faces of the rectangular prism (001); the first, second and third adhesive layers are made from chromium; said pressure lies in the range of 50-100 kg/cm2, during at least part of the time when the lithium niobate plates are pressed to acoustic line; voltage of 10-50 V is applied across each lithium niobate plate at antiresonance longitudinal vibrations of the corresponding lithium niobate plate for 1-3 minutes; the resulting workpiece, which is in form of an acoustic line with antireflection coatings, first adhesive layer, first gold layer and first indium layer lying successively on the acoustic line, and successively lying second indium layer, second gold layer, second adhesive layer of one of the lithium niobate plates and the lithium niobate plate itself, as well as the nearby successively lying second indium layer, second gold layer, second adhesive layer of another lithium niobate plate and the lithium niobate plate itself, as well as the third adhesive layer and third gold layer lying on each of said lithium niobate plates, is cut into separate elements in parallel to planes (110) of the TeO2 monocrystal.
EFFECT: high efficiency of the device while simultaneously increasing efficiency of the manufacturing process.
1 cl, 3 dwg
SUBSTANCE: piezoelectric device consists of a number of stacked layers of piezoceramic material. Each layer has two flat inner electrodes with engagement factor less than 100%; they contact in sequence with either left or right external electrodes which are located at side wall of the device. The device also contains additional uniformly distributed layers of material with high thermal conductivity, for example, aluminium nitride (AlN), beryllium oxide (BeO) or silicon carbide (SiC) or similar materials. Thickness of additional layers is not less than thickness of piezoceramic layers. Number of additional layers is determined by ratio for product of thickness, number of layers and thermal conductivity of main and additional layers.
EFFECT: reduction of inner temperature gradients, improvement of reliability and operating life.
2 cl, 1 dwg
SUBSTANCE: piezoelectric drive with 3D packet piezoelement for installation on basic structure has at least one surface of packet piezoelement, which is exposed to 2D or 3D profiling perpendicularly to layers of packet, and this at least one profiled surface is fit to circuit of basic structure, at which drive should be installed.
EFFECT: invention provides for high capacity of piezoelement and piezoelectric drive with simultaneous elimination of piezoelement damage risk in process of installation onto part.
17 cl, 12 dwg
SUBSTANCE: radiator of plane ultrasonic wave represents coaxial construction containing the set of piezoelements in the form of plane rings, which is enveloped on two sides with parts made in the form of bushes. In holes of piezoelements and bushes, along the construction axis there arranged is resonant waveguide acoustic transformer. This transformer serves as tie bar as well. At that, projection of connection of tie bar and the second bush to radiator axis includes the point belonging to the plane of equal amplitudes of coupled vibrations of itself and the construction tied with it if it can be assumed solid and when there is no that connection. Radiator can include several sets of piezoelements alternating with bushes and tied with common tie bar, which increases mechanical radiation power proportionally to the number of those sets.
EFFECT: increasing efficiency owing to decreasing energy losses in mechanical connections of its vibrating system.
1 tbl, 4 dwg
FIELD: piezoelectric drives.
SUBSTANCE: proposed piezoelectric drive characterized in high economic efficiency has housing accommodating thin-walled piezoelectric cylinder, electrodes exciting resonance-tuned bending vibrations, and at least two multilayer cylinders shielded by wear-resistant flexible shells within housing. Multilayer cylinders are assembled by inserting one into other for alternate vibration in convexo-concave manner relative to one another thereby varying cylinder-to-cylinder space filled with material in the form of liquid or air. This material in the form of liquid or air brought to water hammer condition in conjunction with hydraulic ram or supersonic air speed creates superfluidity of material in the form of liquid or air. In addition, proposed device is distinguished by high mechanical endurance at system resonance ensuring superconductivity; the latter and multilayer cylinders jointly provide for minimal voltage requirement for exciting and passing maximal current.
EFFECT: enhanced economic efficiency, ability of handling considerable forces and displacements.
2 cl, 2 dwg
SUBSTANCE: proposed converter designed for operation as actuating device in adaptive optical systems has multilayer stack of plates electrically connected in parallel with double-layer ferroelectric ceramic plate with diffused phase transition. One layer of double-layer plate has slot of depth equal to thickness of this layer. Axes of slots in adjacent double-layer plates are disposed in relatively perpendicular planes.
EFFECT: elongated travel distance of operating element, enhanced time and temperature stability.
1 cl, 2 dwg