Abstract: An alternator system having an alternating current (ac) voltage source includes a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an output of the alternator system, and a controller coupled to said switched-mode rectifier so as to provide a controlled pulse sequence synchronized with an angular rotor position of the (ac) voltage source to activate and deactivate the switched-mode rectifier The controller further includes a PWM generator having a first input to receive a total duty ratio signal synchronized with an angular rotor position of the (ac) voltage source The switched mode rectifiers are controlled to increase power output levels at lower speeds near idle The controller combines improved idle speed power output levels with load matching improvements from PWM control for more efficient operation when compared to circuits using conventional control or PWM load matching control alone

Abstract: A double control apparatus capable of saving power and a power control method thereof are provided. The double control apparatus has a first power supply unit for converting alternating current (AC) power input from the outside into direct current (DC) power, and providing the DC power as the first power; a function performing unit, which is driven in response to a second power, for performing predetermined function(s); an external interface unit, which is driven in response to the first power and the second power, for receiving control information from the outside and outputting input state information to the outside; an auxiliary control unit, which is driven in response to the first power, for receiving the control information from the external interface unit, outputting the state information to the external interface unit, and in response to a sleep mode signal, outputting a power control signal; a main control unit, which is driven in response to the second power, for outputting the state information, which is obtained by executing a program for controlling the function performing unit, to the auxiliary control unit in response to the control information input from the auxiliary control unit, and generating the sleep mode signal in response to the result of checking whether or not performing the predetermined function by the function performing unit is completed; and a second power supply unit for outputting the first power as the second power in response to the power control signal. Therefore, power can be saved in the sleep mode.

Abstract: A plural output control station for operating electrical apparatus, such as model electric train engines and accessories. The control station employs a data processor for monitoring and controlling the signals generated at a plurality of transformer-driven power output terminals. An exemplary station includes two variable-voltage alternating current (AC) output channels (TRACK 1 and TRACK 2 ) and two fixed-voltage AC output channels (AUX 1 & AUX 2 ). The variable-voltage outputs are controlled by a data processor responsive to respective operator-controlled throttles for varying the AC output voltage and therefore the rate of movement and direction of electric train engines, typically three-rail O-gauge model trains. The variable-voltage outputs can also be offset by the data processor with positive and negative DC voltages for enabling engine functions such as horns, whistles and bells. The variable-voltage outputs are controlled by the data processor to also communicate control parameters to electric train engines for the operation and programming of various electric train engine features and accessories. The plurality of outputs are monitored by the data processor to ensure that predetermined voltage and/or current limits are not exceeded by any individual output and that a predetermined power limit is not exceeded by any individual output or by any combination of outputs.

Abstract: A direct-current power supply (40) is connected between the neutral points of two three-phase coils (24, 26) of a 2Y motor (22) constituted of the windings of the two three-phase coils (24, 26), which are connected in Y-connection and wound on a same stator, and to which three-phase alternating current power is severally supplied with a phase difference of a shifted angle between the windings from two inverter circuits (30, 32) having a positive pole bus (34) and a negative pole bus (36) for common use. A capacitor (38) is connected between the positive pole bus (34) and the negative pole bus (36). The electric potential difference between the neutral points of the three-phase coils (24, 26) is made larger or smaller than the voltage of the direct-current power supply (40) through the switching control of the inverter circuits (30, 32). Thereby, the capacitor (38) can be charged or discharged. Consequently, an inverter input voltage can be adjusted within a wide range.

Abstract: The stable operating-power limits of a small scale HVDC system composed of voltage source converters (VSC-HVDC system) are analyzed with a simple model. The VSC-HVDC system could operate where the AC system must be somewhat larger in capacity than the VSC-HVDC system capacity. The stable operating power limits were between one and two times the SCR (short circuit ratio). When the inverter of the VSC-HVDC system was operated with lead reactive (capacitive) power control conditions, the stable operating limits were increased through AC voltage stabilization. If there were loads near the inverter, the VSC-HVDC system could transmit a little bit larger power than those without loads.

Abstract: The characteristics of the address discharge of an alternating current plasma display panel (ac PDP) adopting a ramping reset pulse were studied using two-dimensional (2-D) numerical simulation. We investigated the principal parameters of the reset pulse for a successful address discharge. In this paper, we suggest a new parameter, the terminal voltage of the ramping reset pulse, and its effects on the minimum address voltage and current flow characteristics during the address discharge. The minimum addressing voltage decreased with increase in the ramping-down time and with increase in the terminal voltage of the ramping reset pulse, which were explained with the wall charge characteristics obtained by a 2-D simulation and confirmed through an ac PDP experiment.

Abstract: In a rectifier circuit that rectifies an alternating current voltage generated by a generator and supplies the alternating current voltage to a capacitor as a power storage unit, a plurality of level shifters supplies a voltage level-shifted by an offset voltage to respective comparators when the comparators corresponding to transistors perform an on-and-off control, based on voltages across terminals of each of a plurality of transistors forming the rectifier circuit. The offset voltage is set accounting for a response delay time of each comparator. Each transistor is reliably turned off at the time the transistor should be turned off in relation to the voltage across the output terminals of the generator. As a result, a reverse current from the capacitor is thus prevented. A delay in the timing of turning off each transistor is eliminated.

Abstract: A remote receiver unit is for use in an animal behavior modification system that applies an electrical shock to an animal. The remote receiver unit has an electrical shock device including two electrodes configured for contacting the animal, a source of alternating current voltage, and an electrical transformer with a primary coil and a secondary coil. The primary coil is electrically connected to the source of alternating current voltage. The secondary coil is electrically connected to at least one of the two electrodes. The transformer has an output impedance of less than 900 ohms. A receiver circuit is electrically connected to the shock device. The receiver circuit is configured for activating the shock device in response to a received signal.

Abstract: A flywheel uninterruptible power supply has an energy storage flywheel supported in a low pressure containment vessel for rotation on a bearing system. A brushless motor/generator is coupled to the flywheel for accelerating and decelerating the flywheel for storing and retrieving energy. The flywheel is rotated in normal operation at a speed such that the generator voltage is higher than the output voltage. Power supplied to the load from the generator is a regulated output that is maintained at a substantially constant voltage level by using switching regulation of the alternating current voltage generated by the generator. The switching regulation of each generator phase occurs at a frequency equal to or less than twice the frequency of the generator alternating current. As so operated, the flywheel uninterruptible power supply efficiently maintains power to an electrical load during an interruption of primary power by supplying power generated from the flywheel generator.

Abstract: A device and a method for controlling the flow of electric power in a transmission line carrying alternating current, in which a first voltage source converter is connected to the transmission line at a first point and a second voltage source converter is connected to the transmission line at a second point. Further, the first and second voltage source converters have their direct current sides connected to a common capacitor unit. Also included is a by-pass switch connected to the transmission line between the first point and the second point in parallel with the first and second voltage source converters so that the first and second voltage source converters will operate as a back-to-back station when the by-pass switch is open and as two parallel static var compensators when the by-pass switch is closed.

Abstract: A new generating method of compression waves in a liquid metal has been proposed in which a static magnetic field and an alternating current are simultaneously imposed. The theoretical expressions of intensities and distributions of pressure and velocity accompanied with the compression waves have been derived. The pressure change in liquid gallium excited by the method proposed here was measured under different intensities of the magnetic field and the alternating current. The measured pressures approximately agreed with the theoretical evaluation. The structure of a Sn–Pb alloy that was solidified under the imposition of the compression waves, was completely refined.

Abstract: The invention describes a method and a device for transporting a signal over a power line. The inventive method includes inducing an alternating current (AC) voltage from the power line, powering a transceiver device with the induced AC voltage, communicating the signal with the transceiver device via the power line. The method further may include transmitting and/or receiving the signal with an end user via the transceiver device. The transceiver device may be a fiber optic-based device that transmits data to the end user over non-metallic fiber optic links. The method may filter the induced AC voltage, and separately filter the signal.

Abstract: In an inverter which implements drive control on a three-phase AC motor by detecting a first-phase current value and a second-phase current value among three-phase alternating current values with two current sensors, one of the current sensors is determined to be abnormal if one of the absolute value of the deviation of the first-phase current detection value relative to a first current command value and the absolute value of the deviation of the second-phase current detection value relative to a second-phase current command value exceeds a first judgement reference value while the three-phase AC motor is being driven.

Abstract: An apparatus for controlling an elevator which has a high energy-saving effect based on charging while using a low-capacity and low-priced secondary battery The apparatus has a converter for converting an alternating current from an ac power supply into a dc power by rectifying the alternating current, an inverter for driving an electric motor by converting the dc power from the converter into variable-voltage variable-frequency ac power, the motor being driven for the operation of the elevator, and a power accumulator connected to a dc bus between the converter and the inverter The power accumulator accumulates dc power from the dc bus during regenerative operation of the elevator, and supplies the accumulated dc power to the dc bus during power-drive operation of the elevator The apparatus also has charge/discharge control circuit for controlling charging/discharging of the power accumulator from or to the direct current bus, and a measuring device for measuring at least one of the temperature, current and voltage of the power accumulator The charge/discharge control circuit adjusts the maximum value of the current for charging/discharging of the power accumulator according to an output from the measuring device

Abstract: A new high-voltage, high-speed pulsed electro-acoustic (PEA) apparatus for real-time measurements of space-charge distribution in solid insulators subjected to rapidly varying voltages is described. Very high-rate PEA measurement is accomplished with the use of a high-speed real-time data acquisition module known as the `Eclipse' unit and a purpose-built high-voltage FET switch pulse generator. Real-time space-charge measurements with good phase resolving capability can be made under time varying applied stresses, e.g. voltage transients or ac conditions. The high-field PEA system has been used to investigate the space-charge dynamics in polyethylene samples stressed by 0.2 and 50 Hz sinusoidal ac voltages.

Abstract: Providing a discharge lamp device to reduce noise radiation and to reduce a surge pulse current resulting from a shield sheath involves providing a ballast, including a DC/DC conversion circuit for boosting a direct current voltage from a battery, an inverter circuit for converting the voltage boosted by the DC/DC conversion circuit into an alternating current voltage, a starting circuit having a second transformer for boosting to such a voltage that causes a breakdown between electrodes of a lamp in starting up the lamp, and a metal case for accommodating the DC/DC conversion circuit, the inverter circuit, and the starting circuit. A secondary winding of the second transformer of the starting circuit is connected between the lamp and the inverter circuit connected to the lamp. An electrode member is interposed between the second transformer and the metal case.

Abstract: A wind power plant that comprises at least one wind power station which includes a wind turbine (12), an electric generator (6) driven by the wind power station, and an electric alternating current connection (10) which connects the wind power station to a transmission or distribution network (14). The wind turbine (12) and the generator (6) are connected directly via an elastic coupling (4).

Abstract: An apparatus and method are disclosed for accurately detecting the detachment of both electrically conductive and non-conductive implants which have been introduced to and are intended to remain at a desired therapeutic site. The detachment detection apparatus may include a conductive or an electrically-isolated implant, such as a vasoocclusive coil, connected to a wire by an electrolytically severable joint. The detachment assembly further includes a power supply having a direct current drive circuit for supplying a direct current to the joint, an alternating current drive circuit for independently supplying an alternating current to the joint, and an alternating current monitoring circuit for monitoring an alternating current level of the alternating current supplied to the joint. The detection assembly includes a central processing unit for selecting a first mode and a second mode for determining a detachment threshold level indicating detachment of the implant. Additionally, a direct current monitoring circuit is providedfor measuring a direct current impedance level of the direct current supplied to the joint wherein a percentage increase in the direct current impedance level indicates detachment of the implant if the alternating current level is greater than the detachment threshold level.

Abstract: Disclosed is an array for contactless transmission of electrical signals or energy from at least one transmitter to several receivers. The invention is characterized in that each transmitter contains an alternating current source or a source of current (1) and several inductive coupling elements (2, 22), (3, 23), (4, 24) powered by the latter, which are transformed into resonance-capable elements by a capacitor (32, 33, 34), in addition to a control element that controls the alternating current source or the source of current in such a way that it operates at a resonance frequency of the resonance-capable element.

Abstract: A method of and a device for operating a gas discharge lamp which is fed with an alternating voltage or an alternating current and wherein the instantaneous power of the lamp is increased at given time intervals are used to form the electrodes. The value of an operational datum of the lamp which varies in time is continuously or discontinuously measured and the frequency of the alternating voltage or the alternating current (operating frequency) is selected in dependence on the measured values.

Abstract: An alternator system having an ac machine includes a switched-mode rectifier operating at a duty cycle selected based upon at least one of the emf, frequency or speed of operation of the ac machine. The switched-mode rectifier operates such that the alternator system provides a load match which results in output power levels which are relatively high compared with output power levels of conventional alternator systems. In one embodiment a system for charging a first source from a second source includes an alternating current (ac) voltage source having a connecting system for selectively connecting a positive terminal of the second source to the ac voltage. The charging system approach may be utilized in a dual output voltage alternator system.

Abstract: In many applications, piezoelectric transducers are driven at AC voltage levels well beyond the level for which the material was nominally characterized. In this paper we describe an experimental setup that allows for the determination of the main transducer or resonator properties under large AC drive. A sinusoidal voltage from a waveform generator is amplified and applied across the transducer/resonator in series with a known high power resistor. The amplitude of applied voltage and the amplitude and the relative phase of the current through the resistor are monitored on a digital scope. The frequency of the applied signal is swept through resonance and the voltage/current signals are recorded. After corrections for the series resistance and parasitic elements the technique allows for the determination of the complex impedance spectra of the sample as a function of frequency. In addition, access to the current signal allows for the direct investigation of non-linear effects through the application of Fourier transform techniques on the current signal. Results determined from resonators of both soft and hard PZT and a ultrasonic horn transducer are presented.

Abstract: A flywheel uninterruptible power source has a charging system that uses a high frequency pulse width modulated inverter inside the motor drive with a very low frequency, line commutated converter that regulates by switching the alternating current from the utility power at frequencies under 200 Hz and 60 Hz. The placement of the motor power regulation switching is moved from the motor drive preferably to the input AC line current that provides power to charge the flywheel system. The switching is preferably done using natural commutation so that the devices are turned off when the current passes through zero for very low loss and device stresses. Preferable devices for switching include thyristors or triacs. The turn on switching can be accomplished using phase angle firing or in one embodiment zero cross over switching is employed to reduce harmonic distortion and radio frequency interference to the primary source.

Abstract: An apparatus for controlling an elevator which has a high energy-saving effect based on charging while using a low-capacity and low-priced secondary battery. The apparatus has a converter for converting an alternating current from an ac power supply into a dc power by rectifying the alternating current, an inverter for driving an electric motor by converting the dc power from the converter into variable-voltage variable-frequency ac power, the motor being driven for the operation of the elevator, and a power accumulator connected to a dc bus between the converter and the inverter. The power accumulator accumulates dc power from the dc bus during regenerative operation of the elevator, and supplies the accumulated dc power to the dc bus during power-drive operation of the elevator. The apparatus also has charge/discharge control circuit for controlling charging/discharging of the power accumulator from or to the direct current bus, and a measuring device for measuring at least one of the temperature, current and voltage of the power accumulator. The charge/discharge control circuit adjusts the maximum value of the current for charging/discharging of the power accumulator according to an output from the measuring device.

Abstract: Each cell of a PDP is provided with a pair of narrow and substantially U-shaped plane electrodes, which are connected to a corresponding trace electrode at the open ends thereof (located at the respective non-discharging gap sides) to operate as scan electrode and common electrode. A plane discharging gap is defined between the closed front ends of the plane electrodes. The plane electrodes have a curved profile at the front ends thereof with the highest point located at the longitudinal central axis of the cell. With this arrangement, the effective length of the plane electrodes can be increased without increasing the surface area of the plane electrodes so that the plane electrodes overlap the data electrode at the front ends thereof over an expanded area.

Abstract: Electric fields were measured using laser induced fluorescence spectroscopy and the wall voltage was estimated from the measured electric fields in a surface-type alternating current plasma display panel cell with a helium discharge (100 Torr) driven by square sustaining pulses. The wall voltage showed very complicated, temporally dynamic behavior. The polarity of the wall voltage changed rapidly as soon as the plasma was ignited, and its magnitude continuously increased due to the continuous injection of charged particles onto the dielectric surface from the afterglow plasma during the rest of the pulse-on period. When there was a self-erasing discharge at the instant of the pulse turn-off, the wall voltage dropped sharply by about 110 V and decreased continuously owing to the diffusion-induced charge redistribution or leakage. The decay rate of the wall voltage during the pulse-off period was very dependent on the surface condition of the protecting layer of the dielectric.

Abstract: A measuring system has at least four electrodes and an electric current measuring resistance placed in a material under measurement in a desired manner. A power supply supplies an alternating current between two of the electrodes through the resistance. A current measuring unit measures an electric current flowing through the resistance. A voltage measuring unit measures an electric potential difference between electrodes other than the electrodes supplied with the alternating current. A computing unit obtains a conductivity, and performs conversion based on calibration data to obtain the amount of a specific substance mixed in the material under measurement. An electrode rod has a plurality of annular electrodes and a plurality of spacers, each having an inner diameter corresponding to the outer diameter of the inner cylindrical portion. A cable lead-in opening is provided in the wall surface of the inner cylindrical portion. The annular electrodes are fitted onto the outer periphery of the inner cylindrical portion one after another at spacings determined by the spacers, and cables are led to the annular electrodes through the cable lead-in opening.

Abstract: An electrical power generating system is described for generating electrical energy for an electric vehicle, via the motion of the non-drive wheels, which converts kinetic energy to electrical energy to replenish the batteries of said vehicle. The preferred version places one or more alternator/generator(s) at the non-driven wheels of the vehicle. Each alternator/generator is unitarily formed with respect to a mounting plate unitarily formed with respect to said mounting plate and said vehicle's suspension, and each alternator/generator includes a rotating field means integrated with the rotating mounting plate attached to the wheel and a stationary stator means stationarily attached to the frame through the suspension. Conventional electrical contact means attached to between said rotating field means and said stationary stator means for generating electrical current for said vehicle. Since the mechanical loading on the spindle bearing assemblies has been substantially increased, the bearing assemblies of the invention are of a heavy-duty design. That is, such bearing assemblies are large enough to handle the weight of said vehicle, including that of the alternator, as well as the weight of the wheel assembly, including tire and brakes. As the vehicle moves forward or backward, the rotational force applied to the vehicle's wheels will rotate the integrated rotating field means relative to the stationary stator means to produce alternating current (AC). Alternating current is converted to direct current (DC) either by a diode bridge, transformer, or controller, for distribution to the EV's electrical system. DC electricity is used to recharge storage batteries, provide electricity for the drive motor and operate the vehicle's electrical equipment. Thus, the regenerative system, does not add any additional load on the drive motor. Wheel bearing assemblies are usually used for all wheels on vehicles and the very nature of bearing assemblies are to reduce friction. By the incorporation of alternators into the wheel bearing assemblies, a vehicle can generate electricity when moving, without additional workload to the drive train; since wheel bearing assemblies are a necessary and integral part of any rolling vehicle and by their very nature reduce friction and resistance.