Abstract: A circuit (10) for driving a piezoelectric transformer (12) in a phase locked mode without using an external reference signal. The circuit (10) utilizes a 555 timer circuit operated in a stable mode which is responsive to a feedback phase signal (18) coupled from an output signal (20) of the piezoelectric transformer (12). The feedback phase signal (18) overpowers the trigger circuit of the timer to phase lock the timer to an output of the piezoelectric transformer (12) at a resonant frequency of the piezoelectric transformer (12). The circuit (10) provides a simplified phase lock circuit without the need for a typical PLL configuration.

Abstract: A motor structure having a stator core including an armature coil wound on stator plates and arranged in parallel on the surface of the motor mounting plate and a bearing mechanism for supporting a rotor rotatably provided at the center of the stator oppositely to the stator wherein the stator core is coupled by an integrally molded form with a housing for holding the bearing mechanism

Abstract: A rotor for a motor which can provide a great supply of mechanical power using only slightly more input power, because magnetization is sped up when the rotor is rotated by a rotating magnetic field from a stator. The rotor includes laminated sheets of silicon steel. The weight of the rotor is separated into several pieces by inserting a non-magnetic plate between laminated sheets of silicon steel which make up the rotor. The phase angle of the rotor therefore remains synchronized with the rotating magnetic field from the stator.

Abstract: A magnetic field core and armature core are provided on a rotor in spaced-apart relation to each other. Windings for producing rotating magnetic poles are positioned on the magnetic field core, and armature windings are positioned on the armature core. The rotor includes a plurality of magnetic sections which are magnetically coupled with the magnetic field core and armature core, but the magnetic sections are magnetically separated from each other in a direction of rotation of the rotating magnetic poles. Magnetic poles produced on the rotor will be coupled together through a magnetic path formed by the rotor and armature core. Thus, by passing three-phase alternating currents, corresponding to the magnetic poles produced on the rotor, through the armature windings, torque is developed in accordance with the Fleming's rule, so that the rotor is caused to rotate as a motor at a synchronous speed.

Abstract: There is provided a piezoelectric transformer including (a) a cylindrical body made of piezoelectric material and longitudinally defining a driven section and a voltage generating section, the voltage generating section being polarized in one of directions in a direction of a longitudinal axis of the cylindrical body, (b) a pair of first electrodes formed at a curved surface of the cylindrical body in the driven section and defining a plurality of regions in the driven section in a direction of a longitudinal axis of the cylindrical body, the first electrodes being electrically isolated with each other, the regions being polarized so that every other regions are polarized in opposite directions in a direction of a longitudinal axis of the cylindrical body, the pair of first electrodes comprising a plurality of strip-shaped electrodes wound around the cylindrical body and disposed in parallel with one another in a direction of a longitudinal axis of the cylindrical body, every other strip-shaped electrodes bei

Abstract: A ground fault interrupter circuit ("GFIC") device having as a switching device a flextensional electroactive transducer which, when energized, opens a supply conductor between a current source and a load. When a fault current is detected a voltage is induced in a coil; due to the condition that there is less current running through the conductor from the load than through the conductor from the power supply which both extend through the core of the coil. The voltage induced in the coil is amplified by a transistor which causes the transducer to piezoelectrically "snap" from a first neutral position to a second neutral position thereby cutting of current from the power supply to the load.

Abstract: A power tool is provided having a housing with a handle for an operator, a rare earth permanent magnet motor oriented within the housing having a rotary output portion operatively driving an implement. The motor has a relatively high horsepower output for its size enabling the location of the motor relative to the implement and the handle to be functionally and ergonomically optimized.

Abstract: A hybrid type stepping motor includes coils located on the outer or inner periphery of stator yokes provided on a fixed shaft. This structure allows the coils to be disposed more easily and thus at a lower cost. Furthermore, it is possible to achieve a great increase in the density of winding. Auxiliary magnetic plates and auxiliary magnets are disposed at both ends of a stator yoke assembly so that a magnetic circuit is formed at both ends. According to the invention, a motor having any desired number of phases may be achieved. A magnet is disposed in each space between adjacent teeth of either a rotor or a stator or otherwise of both rotor and stator. The magnetomotive force of the magnet suppresses leakage magnetic flux and concentrates the magnetic flux within the region between the rotor and stator. As a result, in operation, an abrupt change in the magnetic flux can be obtained, which leads to an increase in the torque.

Abstract: In a resonator type surface acoustic wave filter, a fundamental mode of a mode to distribute in a direction perpendicular to propagating direction of a surface acoustic wave (hereinafter referred to as transverse mode) becomes a primary response, whereas a transverse secondary mode becomes spurious. In case of the surface acoustic wave device formed on a piezoelectric substrate having smaller electromechanical coupling factor of a quartz substrate or so forth, it is impossible to obtain sufficient restriction of the second mode spurious. This problem is solved by canceling electrical potential of transverse secondary mode and whereby restricting excitation with a resonator type surface acoustic device formed on a quartz substrate, in which a configuration of an interdigital electrode is selected to establish a ratio of an overlap width of an electrode finger versus an aperture width in a range greater than or equal to 0.75 to smaller than or equal to 0.85.

Abstract: The piezoelectric ignition mechanism of the present invention has a telescopic assembly having an inner and an outer members aided by a return spring for maintaining a maximum extension between the members. The inner member includes a piezoelectric element which is immobilized between an anvil and impact pad over which a plexor strikes to generate a spark. An impact spring for aiding the plexor is guided in the interior of the telescopic assembly and is disposed between the plexor and an end member connected to the outer telescopic member. A resistant spring is also disposed at or near the end member to provide additional resistance to the operation of the piezoelectric mechanism in order to discourage the undesirable operation by young users.

Abstract: A vibration actuator is provided with a rectangular parallelepiped elastic member of which a surface bears electromechanical converting elements adhered thereto and a relative moving member maintained in pressure contact with the other surface of the elastic member. A driving voltage is applied to excite the electromechanical converting elements to generate, in the elastic member, a longitudinal vibration vibrating in a plane parallel to the surface of the elastic member contacting the relative moving member and a bending vibration vibrating in a direction crossing the contacting surface, thereby generating a relative motion between the elastic member and the relative moving member. The elastic member has working portions for adjusting the difference of the resonance frequencies of the longitudinal and bending vibrations.

Abstract: An apparatus having a drive device using an electromechanical transducer capable of being used in an environment in vacuum, at high temperatures and shielded from outside, an environment where electromagnetic waves are shielded or the like, where a drive shaft and a slider block frictionally coupled thereto are arranged at the inside of a hermetically-sealed vessel, one end of a drive shaft is made to penetrate a wall face portion of the hermetically-sealed vessel and the drive shaft is coupled with a piezoelectric element arranged at the outside of the vessel, the wall face portion of the hermetically-sealed vessel where the drive shaft penetrates is made elastically deformable, a portion between the wall face portion and the drive shaft is shielded in airtight by an adhesive agent and elongation and contraction displacements having different velocities are caused at the piezoelectric element whereby the slider block frictionally coupled with the drive shaft and members fixed to the slider block at the insid

Abstract: An active magnetic bearing with auto position-detection includes first and second opposing electromagnets disposed on opposite sides of a ferromagnetic body (1) suspended without contract with the electromagnets. The bearing includes inductive type position detectors which are constituted directly by coils (11, 21) of the first and second electromagnets. A mechanism (14; 24) is provided for injecting a sinusoidal current I.sub.0 sin.omega.t of constant amplitude I.sub.0, of angular frequency .omega., and of identical phase, simultaneously to the inputs of power amplifiers (13, 23) powering the coils (11, 21) of the first and second opposing electromagnets in superposition with the main currents from the servo-control circuits (31, 32). Circuits (41 to 44) serve to extract the position information which determines the magnitude of the main current to be applied by the servo-control circuits (31, 32) to the power amplifiers (13, 23) directly from the voltages u.sub.1, u.sub.

Abstract: An improved composite ultrasonic transducer, and elements therefor, which may be made autoclavable, and a method of making these elements. A number of planar precursors comprising strips of piezoelectric ceramic material separated from one another by a polymer material are stacked one above another with the ceramic strips aligned with one another, and with electrical conductors disposed between each of the planar precursors. These precursors are then bonded to one another, to form a bonded assembly. The bonded assembly is then slit along parallel lines perpendicular to the direction of elongation of the ceramic strips, subdividing the strips into individual ceramic members and also subdividing the planar conductors, forming ribbon-like conductors extending between opposite sides of the array. The saw kerfs are filled with a hardening polymer material. The ribbon-like conductors reaching the edges of the assembly are then connected electrically in parallel, reducing the capacitance of the individual emitters.

Abstract: The invention relates to a composite piezoelectric multilayer element of which, in operation, only a part is piezoelectrically active, and to a method of manufacturing such an element. In accordance with the invention, the piezoelectrically inactive part has larger dimensions in one or more directions than the part which, in operation, is piezoelectrically active when a voltage is applied across the electric connections of the element. Moreover, the inactive part is built up of ceramic foils and electrode layers whose thickness and composition correspond to the thickness and composition of the part of the element which, in operation, is piezoelectrically active. The element in accordance with the invention can be manufactured in a simple and inexpensive manner.

Abstract: The invention comprises a versatile AC dynamo-electric machine (10) comprising isolated dual stators (50 and 50B and 50C), each both concentrated windings (53C) energizable with single-phase AC, and main windings (53) and a single high inertia sleeve (75) and drive plate (74 and 74A) connected to a rotor shaft (70-73A). The sleeve contains independent electrical rotors (80 and 80A), one for each stator. Each rotor has an innermost layer (82) of magnetizable permanent magnetic material in which the concentrated coils in the stator produce a desired pattern of magnetic poles reacting with the rotating field of the main windings. The machine can function (a) as a synchronous AC motor, or (b) a constant frequency output dual AC generator or (c) as an AC motor-generator with long ride-through time. A UPS system (100) comprises the machine (10) in the motor-generator mode, with clutch means (124) to connect an engine (114) to the rotor shaft (73A) to start the engine.

Abstract: A surface acoustic wave position-sensing device comprising two surface acoustic wave transducing units, a nonpiezoelectric plate and a controlling system connected with the units. Each unit consists of two piezoelectric substrates, a first group of interdigital transducers (IDTs) and a second group of interdigital transducers (IDTs). The second group of the IDTs is placed such that the finger direction thereof is slanting to that of the first group of the IDTs by an angle .alpha.. The thickness of each piezoelectric substrate is smaller than an interdigital periodicity of the IDTs. The thickness of the nonpiezoelectric plate is larger than three times the interdigital periodicity. When an electric signal is applied to the first group of the IDTs, a SAW is excited in one of the piezoelectric substrates and transmitted to the other of the piezoelectric substrates through the upper end surface of the nonpiezoelectric plate.

Abstract: Although a rotor shaft of a spindle motor for driving an optical disc is constituted by stainless steel not to cause damage or friction when the disc is mounted or removed, it is intended to provide a spindle motor which does not require to use a material with bad workability such as stainless steel. A rotor shaft or a rotor cap mounted on the rotor shaft is made from a resin material or an alloy material with good workability such as brass, and a hard coating is provided on its surface to provide hardness necessary for components made of a material with good workability.

Abstract: An apparatus for electromagnetically and rotationally vibrating a rotary body that is supported by bearings. The apparatus comprises a ring-shaped magnet bipolarly magnetized and mounted coaxially on a shaft of the rotary body, a ring-shaped stator having a coil and adapted to generate a rotating magnetic field by controlling an electric current supplied to the coil, and a frequency variable vibration power source adapted to supply alternating electric power to the coil in the stator. The distance between a location of a magnetic pole in the stator and an axis of the shaft is different than the distance between a location of a magnetic pole in the magnet and the axis of the shaft. The magnet and the stator are disposed so as to be adjacent to each other. Thus a rotational exciting force is applied to the rotary body by an interaction of the rotating magnet field generated by the stator with the magnet.

Abstract: A hybrid stepping motor according to the present invention has coils wound on stator yokes arranged on a fixed shaft or coils arranged on the inner peripheral surface of stator yokes. For this reason, the coils can be easily formed, a coil mounting density higher than that by a conventional technique can be obtained, and cost reduction can be obtained. An auxiliary magnetic plate and an auxiliary magnet are arranged on both the sides of a stator yoke member to form magnetic circuits at both the ends of the stator yoke member. Therefore, motors having various numbers of phases can be obtained, and a core are partially or entirely constituted by a non-layered structure, thereby improving torque/current characteristics.