Abstract: A generator having a field coil L, and an SW1 control circuit 2 for controlling field current flowing through the field coil L. When a generating operation of the generator is to be ended, a switch 1 SW1 is turned off to interrupt the field current flowing through the field coil L, and a switch 2 SW2 is turned off to allow the field current remaining the field coil L to the current path including a resistance element 1 with a resistance element capable of quickly attenuating the field current.

Abstract: A feedback control method and circuit for inclusion in a control system of an electrical power generating source that comprises a free piston Stirling engine driving a linear alternator. An instantaneous value of a variable, Vinternal, is continuously derived from other sensed and computed parameters and used in a negative feedback control loop of the control system to control engine piston stroke in order to maintain the power produced by the engine equal to the power transferred from the engine to the alternator. Vinternal is the sum of the voltage induced on the alternator winding and the voltage across the equivalent circuit lumped resistance of the alternator winding and a switching mode rectifier connects the alternator winding to an energy storage capacitor or battery.

Abstract: A portable range extender can be used to supply electrical power to an electric vehicle operable by an electric traction motor. The portable range extender includes an engine, a dynamoelectric machine coupled to the engine by a shaft, an autonomous range extender controller for controlling operations of the range extender independently of a controller for the vehicle, and circuitry associated with the engine and machine. To start operation, electrical energization is applied from the vehicle battery to the dynamoelectric machine for operation as a motor to drive the shaft. As the shaft accelerates, the rotational speed of the shaft and the temperature of the engine are sensed. When the speed and temperature obtain predetermined thresholds, fuel is supplied to the engine and ignition is activated. The engine then operates as a prime mover to drive the shaft in lieu of the machine.

Abstract: A piezoelectric micromachined ultrasonic transducer comprising a substrate and a first dielectric film formed on the substrate. An opening having a sidewall is formed through the substrate and first dielectric film. A bottom electrode is formed on the first dielectric film spanning the opening. A piezoelectric element is formed on the bottom electrode. A second dielectric film surrounds the piezoelectric element. A conformal insulating film is formed on the sidewall of the opening. A conformal conductive film is formed in contact with the bottom electrode and on the sidewall of the opening, wherein an open cavity is maintained in the opening. A top electrode is formed in contact with the piezoelectric element.

Abstract: A hybrid piezoelectric energy harvesting transducer system includes: (a) first and second symmetric, pre-curved piezoelectric elements mounted separately on a frame so that their concave major surfaces are positioned opposite to each other; and (b) a linear piezoelectric element mounted separately on the frame and positioned between the pre-curved piezoelectric elements. The pre-curved piezoelectric elements and the linear piezoelectric element are spaced from one another and communicate with energy harvesting circuitry having contact points on the frame. The hybrid piezoelectric energy harvesting transducer system has a higher electromechanical energy conversion efficiency than any known piezoelectric transducer.

Abstract: An engine speed detector detects an engine speed of an engine having a baseline torque versus engine speed curve. A torque sensor detects an engine torque of the engine. A data processor determines if the detected engine speed is within a first speed range and if the detected engine torque is within a first torque range. A motor controller activates an electric motor to rotate substantially synchronously with a corresponding engine speed associated with the detected engine torque in an electric propulsion mode in accordance with a supplemental torque versus engine speed curve if the detected engine speed is within the first speed range and if the detected engine torque is within the first torque range. The supplemental torque versus engine speed curve intercepts the baseline torque versus engine speed curve at a lower speed point and a higher speed point.

Abstract: A resonator of an acoustic compressor is provided at each side of an actuator so that the two resonators are arranged side by side. Two pistons are provided at the inner ends of the resonators and actuated by the actuator. At the outer end of the each of the resonators, a gas is introduced into the resonator through a suction hole. When the pistons are actuated by the actuator, the gases in the two resonators are oscillated and compressed by the piston and discharged through discharge holes at the outer ends of the resonators.

Abstract: A piezoelectric/electrostrictive device is provided, including a substrate, an electrode layer adhering to the surface of the substrate, and a piezoelectric/electrostrictive layer adhering to the electrode layer. The electrode layer is deformed by high-temperature creep. A method for manufacturing the piezoelectric/electrostrictive device is provided including a step of cooling the piezoelectric/electrostrictive device, after firing, at a temperature decreasing rate of at least the rate of natural cooling. The cooling step includes a sub-step of holding the piezoelectric/electrostrictive device at a constant holding temperature that is lower than the firing temperature. The holding temperature is within a range of temperatures at which high-temperature creep occurs in the metal of the electrode layer so that residual stress in the piezoelectric/electrostrictive layer can be reduced.

Abstract: A stacked-type piezoelectric device comprising a ceramic stacked body constituted by alternately stacking ceramic layers and internal electrode layers one upon another, and a pair of external electrodes bonded respectively to a pair of bond surfaces formed on an outer peripheral surface of the ceramic stacked body, in which the ceramic stacked body has, at least partially in a peripheral direction, a groove portion recessed in a groove shape from its outer peripheral surface in such a fashion as to be adjacent to a stacking surface of each internal electrode layer, and a production method thereof.

Abstract: A piezoelectric actuator 1 includes a piezoelectric element 2, which has a pair of electrodes formed on the surface of a piezoelectric ceramic member, as a drive source. The piezoelectric actuator 1 satisfies at least one of the following requirements (a) to (c): (a) the variation width WC in an apparent dynamic capacity C [F] due to a change in temperature should fall within ±11% over a specific temperature range from ?30° C. to 80° C.; (b) the variation width WL in a displacement L [?m] due to a change in temperature should fall within ±14% over the specific temperature range from ?30° C. to 80° C.; and (c) the variation width WL/C in a quotient L/C due to a change in temperature should fall within ±12% over the specific temperature range from ?30° C. to 80° C., wherein C [F] denotes the apparent dynamic capacity and L [?m] denotes the displacement.

Abstract: This invention provides a vibration wave driving apparatus which makes it possible to reduce the localized abrasion of a contact member, and reduce the deterioration of performance due to long-term driving. This vibration wave driving apparatus has a contact member which is provided with fixed portions fixed to the lengthwise opposite end portions of the vibration expanding portion of the vibration member, and a connecting portion integrally connecting the two fixed portions together and having opposite ends fixed beam structure divided into a plurality.

Abstract: A power generating system provides high voltage AC power and low voltage DC power using a single generator. The generator includes a rotor and a stator that is wound with a first winding and a second winding. The first winding has a greater number of turns than the second winding and generates high voltage AC power in response to the rotating magnetic field created by the rotor. The second winding generates low voltage AC power in response to the rotating magnetic field created by the rotor. The low voltage AC power is converted to low voltage DC power by a rectifier. The low voltage DC power is further controlled by a DC-DC converter to generate controlled DC power. A controller monitors the DC power generated by the DC-DC converter, and generates pulse width modulation signals that are provided to the DC-DC converter, selectively increasing or decreasing the controlled DC power provided by the DC-DC converter.

Abstract: The piezoelectric actuator comprises: a plate-shaped piezoelectric body which has a portion polarized in a thickness direction of the piezoelectric body and a portion polarized in a direction oblique to the thickness direction; and a pair of electrodes which are disposed on opposite surfaces of the piezoelectric body facing each other in the thickness direction across the piezoelectric body, have plane-symmetrical portions and plane-asymmetrical portions in relation to the piezoelectric body, are used as polarization electrodes for polarizing the piezoelectric body so that the portion polarized in the thickness direction and the portion polarized in the direction oblique to the thickness direction are formed in the piezoelectric body, and are used as drive electrodes for inducing strain in the piezoelectric body.

Abstract: A system for generating electrical power supply signals includes at least one heat engine having a chamber that undergoes heating/cooling cycle and corresponding pressure variations. At least one piezoelectric transducer is deformed in response to the pressure variations of the heat engine. A power converter transforms the electric signals generated in response to deformation of the piezoelectric transducer(s) to a desired electrical power supply signal. The heat engine preferably uses a geothermal source of cold and an ambient source of hot or vice-versa. Hydrogen can be used as a working fluid, and metal hydride material can be used for absorbing and desorbing hydrogen during the cycle of heating and cooling of the heat engine. A phase change material can also be used. The power converter preferably includes an electromechanical battery with a flywheel storing rotational energy and possibly an electrostatic motor that adds rotational energy to the flywheel.

Abstract: An actuator mechanism having a different magnet polarity arrangement than the conventional mechanisms is provided. The actuator mechanism 100 has a magnet unit 210 that includes magnets 30 and an electromagnetic coil unit 110 that includes an electromagnetic coil. the relative positions of the magnet unit 210 and the magnetic coil unit 110 can change. The magnet unit 210 includes a yoke member 20 and two or more magnets 30. The two magnets 30 are pulled toward the yoke member 20 in the state where identical poles face each other across the yoke member 20.

Abstract: A resonator which is capable of modulating frequencies has a main body having a vibrating body and an elastic supporting body supporting the vibrating body and a frequency modulating unit having a movable contacting part that is movable between a first position away from the elastic supporting body and a second position which is contactable with the elastic supporting body. Since there is a variable vibration length of the elastic supporting body during vibration of the vibration body by the contact between the contacting part and the elastic supporting body, it is possible to change the frequency of vibration extracted from the resonator, when it is necessary.

Abstract: The invention provides means of limiting maximum current conducted through windings of an electric machine having a rotor and a stator. By encouraging an appropriate leakage flux around a winding, a leak impedance can be achieved which may be used, according to the invention, to limit the maximum current in the winding as a matter of machine design.

Abstract: A pizoelectric filter capable of improving the shielding property and increasing the heat releasing property is provided. The piezoelectric device includes a cover and piezoelectric device chips which are stacked and sealed together. The piezoelectric device also includes first external electrodes exposed at an upper surface of the cover and a grounded second external electrode exposed at the upper surface and a side surface of the cover. Electroconductive bonding materials are disposed between the cover and the piezoelectric device chips and all around an outer edge which connects the cover to the piezoelectric device chips so as to form a seal. The electroconductive bonding materials are also connected to the grounded second external electrode.

Abstract: A piezoelectric motor comprising a vibratory element is configured to move a first driven element by vibrations generated by the vibratory element. A second driven element is brought into frictional contact with the first driven element to form a multistage piezoelectric drive system. Alternatively, a selected contacting portion on a support for the first driven element is provided for drivingly engaging the second driven element. The system is configured to also move the second driven element by vibrations generated by the vibratory element, these vibrations being transmitted from the vibratory element into the first driven element and possibly also into the support for the first driven element. The system is preferably configured to move the first and second driven elements independently from each other using only electric signals that are applied to the same one vibratory element.

Abstract: A structure of an upwind type wind turbine and the operating method thereof capable of preventing the occurrence of damage of the blades by evading excessive irregular loads from acting on the blades in the slanting direction in the event of power failure when strong wind blows, are provided. In the upwind type wind turbine having a nacelle supported for rotation on a support, the nacelle is rotated to a downwind position by rotating it by 180° from a normal upwind position and kept in stand-by condition at a downwind position when detected wind speed is higher than the predetermined cutout wind speed, which is the reference wind speed for shifting to an idle operation state. When the detected wind speed is higher than the DWSS wind speed determined based on the maximum permissible instantaneous wind speed, the nacelle is rotated from an upwind position to a downwind position and the yaw brake is released.