Abstract: A phase control apparatus includes a first transistor whose source or emitter is connected to one end of an AC power supply and whose drain or collector is connected to one end of a load, a second transistor whose source or emitter is connected to the other end of the AC supply and whose drain or collector is connected to the other end of the load, a diode bridge that rectifies an AC voltage of the AC supply, and a parallel circuit of a zener diode and a capacitor. The parallel circuit generates a high potential relative to a bridge negative output terminal potential, or generates a low potential relative to a bridge positive output terminal potential. First and second transistor control terminal potentials are switched between the high and the bridge negative output terminal potentials, or between the low and the bridge positive output terminal potentials.

Abstract: A bi-power motor controlling apparatus, which is electrically connected with a motor, includes a driver IC having a first pin and a second pin. The first and second pins are used to receive a first power and a second power, respectively, from outside. The second power is supplied to the driver IC, and the first power is supplied to the motor for controlling the rotational speed of the motor.

Abstract: A boost converter including two or more inductors coupled to an input DC power source and to switches that can each be modulated with a modulation signal to control the output power of the boost converter. Two or more of the modulation signals have a relative phase other than 360° divided by the number of switches.

Abstract: There is provided an inverter device capable of simplifying the circuit structure, lowering the cast, and downsizing of the device. The inverter device detects a switching change of an inverter by a pulse and is equipped with a pulse signal detector capable of detecting a motor residual voltage or a phase and a detector for detecting a residual voltage or a phase. The inverter device includes a voltage detector, a circuit for detecting a pulse signal based on a comparison between a phase voltage detection value per one phase output from the voltage detector and a first reference voltage value, a circuit for detecting a line residual voltage based on phase voltage detection values of two phases output from the voltage detector, and a circuit for detecting a line phase based on a comparison between the line residual voltage and a second reference voltage value.

Abstract: A rotating electrical machine control device includes an inverter; a resolver; a unit; a three-phase/two-phase modulation switching unit; and a motor control unit that switches to a two-phase modulation in a specific region where an electric noise given to the resolver by a rotating electrical machine is large, even in a region where the modulation ratio is smaller than the three-phase/two-phase modulation switching boundary.

Abstract: A phacoemulsification system includes a phacoemulsification handpiece including a cutting tip ultrasonically vibrated by an ultrasonic transducer. A power supply is provided for driving the ultrasonic transducer at a resonant frequency of the transducer and cutting tip and varying power to the transducer, in response to loading of the cutting tip, by phase shifting voltage and current supplied to the transducer.

Abstract: The present invention discloses a control apparatus for a linear compressor which can vary a cooling force and prevent an inrush current. The control apparatus for the linear compressor includes a coil winding body laminated on the linear compressor, a first capacitor connected in series to the coil winding body, a capacitance varying unit being formed in a parallel structure to the first capacitor, and having a capacitor switch, and a control unit for inducing an output change of the linear compressor, by varying the whole capacitance of the control apparatus by controlling the capacitor switch.

Abstract: A control apparatus for an AC-AC direct converter. The control apparatus includes a calculator providing a phase command ?* of an output voltage of the converter, a calculator providing a q-axis current iq by using output currents iu and iw and the phase command ?*, a detector detecting a pulsation component contained in the q-axis current iq, a calculator providing a phase correction magnitude ?cmp so as to decrease the pulsation component, and an adder/subtractor correcting the phase command ?* by using the correction magnitude ?cmp. This apparatus can decrease the output voltage distortion and low frequency torque pulsation and can suppress the increase of an output current without weakening a magnetic flux, even when the converter is operated in an overmodulation region.

Abstract: The invention relates to a method for power control of an electric motor, in particular a motor for driving the suction fan of a vacuum cleaner connected to an AC mains power supply. The power control is effected by varying the phase angle of the electric alternating quantity supplied to the motor by the use of semiconductor switches. AC power supplied to the motor is switched by using different delay times for the switching in each half-period of a full AC period to suppress odd harmonics, particularly the third harmonic of the mains power line frequency. Half-periods of a full period are mirrored in the next consecutive full period in order to suppress even harmonics, particularly the second harmonic of the mains power line frequency. A set of delay times t1 and t2 are defined and selected to be used in further avoiding critical delay time areas for harmonics and minimize the generation of vibrations.

Abstract: A phacoemulsification system includes a phacoemulsification handpiece including a cutting tip ultrasonically vibrated by an ultrasonic transducer. A power supply is provided for driving the ultrasonic transducer at a resonant frequency of the transducer and cutting tip and varying power to the transducer, in response to loading of the cutting tip, by phase shifting drive signals to the resonant converter which supplies power to the transducer.

Abstract: A pulse width modulator (305) for driving a load in a multi-phased power system having circuitry (270) responsive to channel signals for providing an average signal by summing the channel signals at a node (221) which is coupled with a plurality of resistive elements, and having further circuitry for providing an error between said load and said reference potential, and having still further circuitry (250) for summing the channel signals, average signal, and error for providing a respective drive signal for each of the power switches, wherein the error signal and the average signal have complementary effects on a duty factor of the drive signals and the channel signal has an effect contrary to the error signal and the average signal. Further, a plurality of pulse width modulators (305) can be combined as a system (300) by connecting respective nodes (221) for providing current sharing between all phases.

Abstract: Imaginary orthogonal circuit state variables are established to enable transformation of real circuit state variables of a single-phase converter or the zero-sequence circuit of a three-phase converter from stationary coordinates to DQ rotating coordinates, thereby transforming the sinusoidal steady-state operating point of the real circuit into a DC operating point. A control provides the imaginary circuit state variables in a shifted queue comprising memory blocks for storing quarter-cycle shifted real circuit variables. Control of the converter is thus implemented in rotating DQ coordinates to achieve a theoretically infinite control loop gain at the fundamental frequency.

Abstract: A circuit for inputting an ac signal to a digital processor includes a capacitor connected to the input and ground. A rectifier, preferably a transient voltage suppression device, permits the capacitor and also the stray capacitance which couples false signals to the input lead, to charge to one polarity only. A shunt resistor discharges the capacitor on half cycles of opposite polarity, but there is no discharge path for the stray capacitance which therefore charges up to block steady state false ac signals. Series resistors between the rectifier and the input determine, together with the shunt resistor, the minimum input signal level and increase the over surface breakdown voltage to protect the input from transient voltage conditions. A resistor connected between the series resistors and the rectifier, and to ground determines the charging rate of the stray capacitance. The TVS device provides high transient voltage withstand and breaks down without damage in the event of large transients.

Abstract: A flicker compensating apparatus for compensating for flickering due to a variation in the reactive power generated from a DC arc furnace connected by an AC/DC converter to an AC power system, comprises: a current detector for detecting a DC current flowing in the DC arc furnace; a controller for determining the phase control angle of a thyristor included in the AC/DC converter in accordance with the difference between the detected DC current and a predetermined reference current; a calculator for calculating reactive power to be generated by the DC arc furnace, from the detected DC current, the determined phase control angle, and a no-load DC voltage; a compensator including a reactive load connected via thyristor to the power system; and a controller for controlling the phase control angle of the thyristor of the compensator in accordance with the calculated reactive power, for controlling a current flowing across the reactive load, and for permitting the compensator to generate such reactive power as to co

Abstract: Phase shifter to which are applied two signals in a phase opposition (v, -v) is constituted by a first series circuit of a resistor and a capacitor (R.sub.1, C.sub.1), and a second series circuit of a resistor and a capacitor (R.sub.2, C.sub.2). So that neither the relative amplitudes nor the relative phases of all the signals used at the outputs (5, 6, 7, 8) are degraded by the impedance of the stages that follow, the phase shifter includes a first network of a resistor and a capacitor connected in parallel (C.sub.3, R.sub.3), and a second network of a resistor and a capacitor connected in parallel (C.sub.4, R.sub.4). Both the four resistors and the four capacitors of the phase shifter are each substantially equal in value.

Abstract: A method of controlling a six pulse bridge phase controlled rectifier using a microprocessor is provided by the invention herein. The method involves synchronizing an oscillator to the frequency of an ac power source and driving first and second counters with the oscillator. The first counter is used in conjunction with a phase locked loop to monitor and adjust the oscillator frequency. The count of the second counter generates an .alpha. value used in a firing angle match routine. The match routine compares the desired output voltage to the cosine of .alpha. minus an inductance factor. The match routine takes less than 20 microseconds to run allowing a new .alpha. value to be checked every 0.5 degrees for a 60 hertz power source. When a match is found, the thyristors are fired and a reload value projecting a subsequent firing in 60.degree. is calculated for the second counter.

Abstract: A phase shifter includes first and second series-connected resistor circuits each including first and second resistors and each interposed between each one of two input terminals and each one of two output terminals, and includes capacitors each interposed between each one of medium points of the series-connected circuits and each one of two output terminals. The phase shifter also establishes a relationship of RgRl=R.sup.2 where the value of the first resistor is Rg/2, the value of the second resistor is R, and the output resistance between the two output terminals is Rl.