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: 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 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 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: 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: An air conditioning apparatus includes a compressor, indoor and outdoor heat exchangers, an indoor fan, an expansion valve, a refrigerant-pressure-perceiving part, which perceives a pressure of refrigerant sent from the compressor to the indoor heat exchanger, and a control part, which performs startup fan control in which the indoor fan remains stopped until the compressor goes from being at rest to starting up and the pressure perceived reaches a high-pressure threshold. The control part repeats an action of reducing a flow rate of the indoor fan or stopping driving of the indoor fan when the pressure perceived is equal to or less than a low-pressure lower than the high-pressure threshold, and an action of increasing the flow rate of the indoor fan or initiating driving of the indoor fan when the pressure perceived reaches or exceeds a pressure threshold which is higher than the low-pressure threshold.

Abstract: An air conditioning apparatus includes a refrigeration circuit, a magnetic material member, a magnetic field generator, a detector and a controller. The refrigeration cycle has a compressor, an intake-side heat exchanger, a discharge-side heat exchanger, an expansion valve, and a refrigerant tube connected in series by first, second, third and fourth tube parts of the refrigerant tube to form a closed loop. The magnetic field generator generates a magnetic field in order to inductively heat the magnetic material member. The detector detects temperature or pressure in refrigerant flowing through a predetermined portion of the refrigerant circuit. The controller confirms satisfaction of a magnetic-field-generating-permission condition before initiating the magnetic field generator to generate the magnetic field after a startup of the compressor.

Abstract: An air conditioner includes a heat generating member, an electromagnetic induction heating unit, an air conditioning target space temperature detecting unit, an outdoor air temperature detecting unit, and a control unit. The heat generating member thermally contacts a refrigerant piping and/or refrigerant that flows through the refrigerant piping. The electromagnetic induction heating unit includes a magnetic field generating part that generating part generates a magnetic field in order to heat the heat generating member by induction heating. The control unit, when the refrigeration cycle is performing heating operation or defrosting operation, inhibits the generation of the magnetic field by the magnetic field generating part when the temperature of the space to be air conditioned and the outside air temperature do not satisfy a first prescribed condition or when a difference between a target set temperature and the temperature of the space does not satisfy a second prescribed condition.

Abstract: An air conditioner includes a refrigerant circuit, an electromagnetic induction heating unit, and a control unit. The refrigerant circuit has a compressing mechanism with an adjustable operating capacity, a heat source side heat exchanger, an expansion mechanism, and a utilization side heat exchanger. The electromagnetic induction heating unit heats a refrigerant piping and/or a member that is in thermal contact with a refrigerant that flows through the refrigerant piping. The control unit sets the electromagnetic induction heating unit to a forced inhibit state if any one of a condition in which the electromagnetic induction heating unit has been manually set to operation inhibited; a condition in which an air conditioning load is small; and a condition in which an amount of circulating refrigerant is small is satisfied.

Abstract: An air conditioner (10) composed of a refrigerating apparatus includes a controller (90). A heating control section (91) of the controller (90) feeds electric current in an open phase state to an electric motor (62) of a compressor (30) to heat the compressor (30) in operation stop of the air conditioner (10). The heating control section (91) monitors the detection value of an outdoor air temperature sensor (72) during the operation stop of the air conditioner (10) and keeps on stopping feeding the electric current to the electric motor (62) during the time when the detection value decreases.

Abstract: The present invention provides a sheet conveying apparatus and an image forming apparatus capable of preventing occurrence of skew feeding when correcting sheet lateral deviation. A pair of lateral-shift correcting rollers 305 to correct positional deviation in the sheet width direction based on positional deviation quantity detected by a lateral-registration detection sensor 204c is controlled after controlling a skew feeding correcting roller 203 so as to correct sheet skew feeding based on skew-feeding quantity at a sheet leading edge detected by skew-feeding detection sensors 204a and 204b. Then, skew-feeding quantity of the sheet leading edge to be detected by the skew-feeding detection sensors 204a and 204b for correcting skew feeding of the next sheet is adjusted with skew-feeding quantity at the sheet trailing edge detected by the lateral-registration detection sensor 204c after positional deviation in the sheet width direction is corrected.

Abstract: An image forming apparatus image which is capable of accurately correcting the magnification of an image without degrading the quality of the formed image or reducing productivity, to thereby make it possible to cope with an increase in the operating speed of the apparatus. The image forming apparatus is comprised of an image processing section having an image area-separating section, and an image forming section having an exposure control section. The image area-separating section separates image data into at least two kinds of areas. The exposure control section performs magnification correction on at least one area of the image data separated by the image area-separating unit.

Abstract: A heating dedicated air conditioner includes a compression mechanism, an indoor heat exchanger, an outdoor heat exchanger, an expansion mechanism provided between one end of the indoor heat exchanger and one end of the outdoor heat exchanger, a four-way switching valve switchable between first and second states of connection between the compressor and the heat exchangers, a fan ventilating the indoor heat exchanger, and a control unit controlling at least the compressor, the expansion mechanism, the four-way switching valve, and the fan. The control unit switches the four-way switching valve to the second state in a test operation mode, which includes a drain water inhibited interval during which drain water inhibition control is performed. The control unit operates the compressor and stops the fan when the drain water inhibition control is performed.

Abstract: It is an object of the present invention to provide an air conditioner for inhibiting noise increase and heating performance degradation due to frost attachment onto an outdoor heat exchanger. In an air conditioner (1), a determining part (43) of a control unit (4) determines that the amount of frost attaching onto an outdoor heat exchanger (13) is increased when a difference between an outdoor temperature To and an outdoor heat exchanger temperature Te is increased, and executes a frost attaching condition operation control for reducing the rotation speed of an outdoor fan (23). The operating frequency of the compressor (11) is herein increased in accordance with the reduction amount of the temperature of an indoor heat exchanger (15). The control unit (4) includes change amounts preliminarily set for changing the operating frequency of the compressor (11) in stages. The change amounts correspond to the stages on a one-to-one basis.

Abstract: An air conditioning apparatus includes a compressor, an indoor and outdoor heat exchangers, an indoor fan, an outdoor expansion element, a refrigerant-pressure-perceiving part, which perceives a pressure of refrigerant sent from the compressor to the indoor heat exchanger, and a control part, which performs startup fan control in which the indoor fan remains stopped until the compression element goes from being at rest to starting up and the pressure perceived reaches a high-pressure threshold, the indoor fan is driven when the pressure perceived reaches or exceeds the high-pressure threshold. An action of reducing or stopping air volume of the indoor fan when the pressure perceived decreases to or falls below a low-pressure lower than the high-pressure threshold, and an action of increasing air volume or initiating driving of the indoor fan when the pressure perceived reaches or exceeds a pressure threshold which is higher than the low-pressure threshold.

Abstract: An air conditioning apparatus includes a refrigeration cycle, a magnetic field generator, a detector and a control part. The refrigeration cycle has a compression element, a refrigerant tube in thermal contact with a refrigerant flowing through the refrigerant tube and/or a heat-generating member in thermal contact with a refrigerant flowing through the refrigerant tube. The magnetic field generator generates a magnetic field to inductively heat a heating target portion. The detector detects a state quantity in a state quantity detection portion of the refrigeration cycle. The control part performs startup magnetic field generation control during startup of an air-warming operation in which maximum magnetic field output is initiated until the state quantity detected reaches a first target state quantity, and post-startup magnetic field generation control in which the magnetic field output is restricted after the startup magnetic field generation control has ended.

Abstract: An air conditioning apparatus includes a refrigeration cycle, a magnetic field generator, a detector and a control part. The refrigeration cycle has a compression element, a refrigerant tube in thermal contact with a refrigerant flowing through the refrigerant tube and/or a heat-generating member in thermal contact with a refrigerant flowing through the refrigerant tube. The magnetic field generator generates a magnetic field to inductively heat the heat-generating member. The detector detects either temperature or temperature change or pressure or pressure change in refrigerant flowing through a predetermined portion of the refrigeration cycle. The control part permits magnetic field generation in a first compression element state and a higher output second compression element state, and when a magnetic-field-generating-permission condition is satisfied. The condition is either that a value detected by the detector change or that a change be detected in the value detected by the detector.

Abstract: An air conditioner includes a compressing element, a refrigerant cooler, an expansion element, a refrigerant heater, a magnetic field generating part, a circulation volume rate ascertaining part and a control unit. The magnetic field generating part generates a magnetic field in order to perform inductive heating. The circulation volume rate ascertaining part ascertains a circulating refrigerant volume rate. The control unit performs magnetic field output control when the circulating refrigerant volume rate ascertained by the circulation volume rate ascertaining part has increased. When this control is performed the magnetic field generating part is caused to generate a magnetic field, the magnetic field generated by the magnetic field generating part is increased, or the upper limit of the strength of the magnetic field generated by the magnetic field generating part is increased.

Abstract: An air conditioning apparatus includes a compression element, a refrigerant cooler, an expansion element, a refrigerant heater, a magnetic field generator, a generated heat temperature sensor and a control part. The magnetic field generator generates a magnetic field in order to induction-heat a refrigerant tube circulating refrigerant and/or a member in thermal contact with refrigerant flowing through the refrigerant tube. The generated heat temperature sensor senses temperature of a portion that generates heat due to the induction heating. The control part performs superheating protection control in order to increase an opening degree of the expansion mechanism when the temperature sensed by the generated heat temperature sensor reaches or exceeds a predetermined generated heat temperature, or when a rate of increase of the temperature sensed by the generated heat temperature sensor reaches or exceeds a predetermined rate of increase.

Abstract: An air conditioner includes a heat generating member, an electromagnetic induction heating unit, an air conditioning target space temperature detecting unit, an outdoor air temperature detecting unit, and a control unit. The heat generating member thermally contacts a refrigerant piping and/or refrigerant that flows through the refrigerant piping. The electromagnetic induction heating unit includes a magnetic field generating part that generating part generates a magnetic field in order to heat the heat generating member by induction heating. The control unit, when the refrigeration cycle is performing heating operation or defrosting operation, inhibits the generation of the magnetic field by the magnetic field generating part when the temperature of the space to be air conditioned and the outside air temperature do not satisfy a first prescribed condition or when a difference between a target set temperature and the temperature of the space does not satisfy a second prescribed condition.