Abstract: An electric power conversion device which performs conversion to desired voltage using charge and discharge of a DC capacitor includes: a reactor connected to a rectification circuit; a leg part in which diodes and first and second switching elements are connected in series between positive and negative terminals of a smoothing capacitor, and to which the reactor is connected; and the DC capacitor. A control circuit performs high-frequency PWM control for the first and second switching elements using the same drive cycle, with their reference phases shifted from each other by a half cycle, and controls a sum and a ratio of ON periods of the first and second switching elements in one cycle, thereby allowing both high-power-factor control for input AC current and voltage control for the DC capacitor.

Abstract: In this DC/DC converter, a first switching circuit is connected between a first winding of a transformer and a DC power supply, and a second switching circuit is connected between a second winding and a battery. A control circuit includes a first circuit for performing feedback control so as to reduce a difference between a detected value and a command value of charge current, and a second circuit for correcting one of control input and output of the first circuit on the basis of the detected value and the command value. In charging the battery, the control circuit controls a phase shift amount of a first diagonal element in the first switching circuit and a phase shift amount of a second diagonal element in the second switching circuit relative to the drive phase of a first reference element in the first switching circuit.

Abstract: A first winding, a second winding, a fourth winding, and a fifth winding functioning as a transformer are wound around respective side legs of a three-leg core. Third windings functioning as a DC reactor are wound around a center leg. Winding directions of the first winding, the second winding, and the third windings are set so that magnetic fluxes generated by DC currents flowing through the respective windings merge in the same direction at the center leg, and winding directions of the fourth winding and the fifth winding are set so that magnetic fluxes generated by AC currents flowing through the respective windings cancel each other at the center leg. Thus, the transformer and the DC reactor are integrated using the three-leg core, whereby size reduction and loss reduction of the integrated magnetic component are achieved.

Abstract: A gate drive circuit including a drive-on element that applies an on-state voltage to a gate of a drive target semiconductor element and a drive-off element that applies an off-state voltage to the gate is such that a recovery switch, a reactor, and a capacitor are connected in series between output terminals of the gate drive circuit as a recovery circuit that can recover a charge accumulated in input capacitance of the drive target semiconductor element when turning on, and the drive-on element, the drive-off element, and the recovery switch are controlled by a control circuit, whereby power consumption of the gate drive circuit is reduced.

Abstract: This power conversion device includes: a rectification circuit; an inverter circuit having a full-bridge configuration, and having a DC capacitor, and first and second legs each of which has two switching elements connected in series to each other; a transformer; and a control circuit for controlling operation of the inverter circuit, wherein the control circuit controls an ON period for the first leg, thereby controlling increase/decrease in current flowing through a first rectification circuit from an AC input, and controls an ON period for the second leg and a phase shift amount between the ON period for the first leg and the ON period for the second leg, thereby controlling voltage of the DC capacitor to be constant. Thus, it becomes possible to achieve high-power-factor control and output power control at the same time by a single stage of full-bridge inverter circuit.

Abstract: A printer has a printing mechanism for printing on roll paper; RAM storing font data for multiple languages having at least some character codes in common, and the starting address of the font data for each of the multiple languages; a communicator that receives a command specifying starting addresses and character codes; and a controller that reads font data corresponding to the character codes received by the communicator from RAM based on the starting address specified by the command, and controlling the printing mechanism to print based on the read font data.

Abstract: This power conversion device includes a rectification circuit, a reactor, an inverter circuit, and an isolation transformer. The inverter circuit is composed of a first leg A, a second leg B, and a DC capacitor connected in parallel between DC buses. A first AC end of the first leg A is connected to a positive DC terminal of the rectification circuit via the reactor. High power factor control of current iac flowing from an AC power supply via the rectification circuit is performed by PWM control for the first leg A, and voltage Vdc of the DC capacitor is controlled by PWM control for the second leg B using a duty cycle equal to or smaller than that for the first leg A, thereby controlling power outputted to the secondary side of the isolation transformer.

Abstract: A DC/DC converter includes: duty command calculation units for calculating duty command values for first, second, third, and fourth switching elements on the basis of difference voltage between a high-voltage-side voltage command value and a high-voltage-side voltage detection value; and a phase shift duty command calculation unit for calculating a phase shift duty command value corresponding to a phase difference between gate signals for the first and fourth switching elements and gate signals for the second and third switching elements, on the basis of difference voltage between a voltage target value and a charge voltage detection value of a charge/discharge capacitor, wherein gate signals for driving the first, second, third, fourth switching elements are generated on the basis of the duty command values and the phase shift duty command value.

Abstract: A power conversion device includes switching elements, a reactor, and capacitors in each of which plural capacitor elements are connected in parallel to each other. Then, a carrier frequency used for controlling switching of the switching elements is set so that it is less than series resonance frequencies of all of the capacitor elements in the capacitors, and integer multiples of that frequency are each not equal to a parallel resonance frequency.

Abstract: An electric power converter including an electric-power conversion circuit that performs bidirectional conversion of a voltage between a DC power source and a motor and outputs the voltage, a first voltage detector that detects an inter-terminal voltage at the DC power source side of the electric-power conversion unit, a second voltage detector that detects an inter-terminal voltage at the motor side of the electric-power conversion unit, and a controller. The controller includes a first calculator that calculates a main duty, based on a target voltage and the inter-terminal voltage at the motor side, and a second calculator that calculates a sub-duty, based on the main duty, the inter-terminal voltage at the motor side, and the inter-terminal voltage, at the DC power source side, detected by the second voltage detection unit. The controller calculates a duty amount for operating the electric-power conversion unit, based on the main duty and the sub-duty.

Abstract: A power conversion device includes switching elements, a reactor, and capacitors in each of which plural capacitor elements are connected in parallel to each other. Then, a carrier frequency used for controlling switching of the switching elements is set so that it is less than series resonance frequencies of all of the capacitor elements in the capacitors, and integer multiples of that frequency are each not equal to a parallel resonance frequency.

Abstract: In a DC/DC converter, a first switching circuit is connected between a first winding of a transformer and a DC power supply, and a second switching circuit is connected between a second winding and a battery. In charging the battery, a control circuit controls respectively phase shift amounts of first and second diagonal elements in the first and second switching circuits relative to the drive phase of a first reference element in the first switching circuit. During a step-up charge control period, if charge current is positive or zero, the control circuit performs control so that the phase shift amount becomes greater than the phase shift amount by an amount exceeding a short-circuit prevention time for the switching elements, allowing step-up operation to be performed, improving controllability in step-up control.

Abstract: An electric power conversion device includes a transformer composed of three or more windings magnetically coupled with each other, wherein power supply sources, are connected to at least two windings, via switching circuits, a load is connected to at least one winding, and a control circuit temporally divides, within one switching period, a total ON time during which power is supplied, in accordance with the number of the power supply sources, to supply power, the one switching period being the minimum repetitive unit during which power is supplied alternately. The control circuit allocates the divided ON times to the respective switching circuits, and the switching circuits, supply power from the power supply sources, to the load side during the allocated ON times, respectively.

Abstract: An object of this invention is to obtain a control apparatus and a control method for a DC/DC converter, with which a DC/DC converter can be controlled with superior stability and responsiveness while reducing the size of a storage medium. A calculation value is calculated in accordance with a specific control method using a differential voltage between a target output voltage and an output voltage, whereupon a control calculation value is calculated from the calculation value and an input voltage.

Abstract: To provide a DC/DC converter which does not need to switch a change direction of a control value depending on a power transmission direction between low voltage side and high voltage side, and can control a voltage of a charge and discharge capacitor. A DC/DC converter which controls voltage of a charge and discharge capacitor by a controller that performs a ?duty control which changes an ON duty ratio difference of semiconductor circuits, and a phase shift control which changes a phase difference of an ON period of semiconductor circuits.

Abstract: To provide a DC/DC converter which does not need to switch a change direction of a control value depending on a power transmission direction between low voltage side and high voltage side, and can control a voltage of a charge and discharge capacitor. A DC/DC converter which controls voltage of a charge and discharge capacitor by a controller that performs a ?duty control which changes an ON duty ratio difference of semiconductor circuits, and a phase shift control which changes a phase difference of an ON period of semiconductor circuits.

Abstract: A main circuit of a power conversion device includes: an AC/DC converter for performing power factor correction control for a single-phase AC power supply; and a DC/DC converter connected to the AC/DC converter via a DC capacitor. In order to reduce ripple voltage and ripple current for the DC capacitor, a control circuit superimposes, onto a DC current command, an AC current command having the minimum value at the zero cross phase of the single-phase AC power supply and having the maximum value at the peak phase thereof, to generate an output current command for the DC/DC converter, and performs output control for the DC/DC converter, using the output current command.

Abstract: A medium processing apparatus includes a sensor that is intermittently energized and detects a predetermined physical quantity and outputs the detection value in the energization period, the sensor stabilizing its output after an output stabilization period, which is shorter than the energization period, has lapsed, a storage unit that stores the detection value that has been detected by the sensor before the lapse of the energization period and after the lapse of the output stabilization period, and a controller that reads the detection value from the storage unit and performs a predetermined process by using the detection value read.

Abstract: In a DC/DC converter, a first switching circuit is connected between a first winding of a transformer and a DC power supply, and a second switching circuit is connected between a second winding and a battery. In charging the battery, a control circuit controls a phase shift amount of a first diagonal element in the first switching circuit and a phase shift amount of a second diagonal element in the second switching circuit relative to the drive phase of a first reference element in the first switching circuit. During a step-up charge control period, if charge current is positive or zero, the control circuit performs control so that the phase shift amount becomes greater than the phase shift amount by an amount exceeding a short-circuit prevention time for the semiconductor switching elements. Thus, step-up operation is prevented from becoming unable to be performed due to the short-circuit prevention time.

Abstract: A power conversion device that distributes input power to multiple outputs in accordance with power requirement of a load, using a plurality of magnetically coupled windings. In the case of supplying power from an AC power supply, at least one of an AC/DC converter and first to fourth switching circuits controls voltage on an output side of the AC/DC converter, based on a deviation between a detected value and a target value of the voltage. In the case of supplying power from a first DC voltage source or a second DC voltage source, the second switching circuit or the fourth switching circuit provided between the first DC voltage source or the second DC voltage source and the transformer supplies power based on an arbitrary time ratio.