Abstract: A motor drive control apparatus according to the present invention includes: a three-phase rectifier to rectify an AC voltage supplied from a three-phase AC source; a booster circuit including a reactor, a switching element, and a backflow preventing element, to boost a DC bus voltage supplied from the three-phase rectifier; a smoothing capacitor to smooth an output of the booster circuit; and an inverter circuit to convert the DC bus voltage smoothed by the smoothing capacitor into an AC voltage and supplying the AC voltage to a motor. During a starting operation of a boosting operation of the booster circuit or a stopping operation of the boosting operation thereof, a rotation speed of the motor is fixed.

Abstract: Provided is a power converter for converting electric power between a power source and a load, including: a boosting device including a boost rectifier configured to prevent a backflow of a current from the load side to the power source side, the boosting device being configured to change a voltage of electric power supplied from the power source to a predetermined voltage; a commutation device configured to perform a commutation operation of directing a current flowing through the boosting device to another path; and a controller configured to perform control related to the voltage change of the boosting device and control related to the commutation operation of the commutation device, in which the commutation device is configured to flow, when the commutation device performs the commutation operation, a current generating a voltage causing reverse recovery of the boost rectifier to the commutation device side.

Abstract: A backflow preventing device includes a backflow preventing element that is connected between a power supply and a load and that prevents electric current from flowing backward from the load side toward the power supply side, a commutating device that performs a commutation operation for causing the electric current to flow to a commutation path connected in parallel with the backflow preventing element, and a controller that sets a time for performing the commutation operation and causes the commutating device to perform the commutation operation based on the set time. The backflow preventing device has a plurality of the commutation paths and has, for example, elements with small current-carrying capacities disposed in the commutation paths to achieve cost reduction and to cope with, for example, failures, thereby allowing for enhanced reliability for reducing recovery electric current.

Abstract: An air conditioner includes: an outdoor fan provided in an outdoor unit; a permanent magnet synchronous motor that drives the outdoor fan; an inverter that uses a DC power source as a power source and applies a voltage to the permanent magnet synchronous motor; an inverter control means that controls the output voltage of the inverter; and a shunt resist connected between the DC power source and the inverter. If the outdoor fan is rotating due to an external force while the inverter is stopped, the inverter control means causes the inverter to operate using a brake sequence that brakes the rotation of the outdoor fan, and then causes the inverter to operate using a drive sequence that power-drives the outdoor fan.

Abstract: A power conversion device includes: a rectifier, a converter unit including a reactor, a backflow prevention element, and a switching element, the converter unit being configured to boost a DC voltage rectified by the rectifier, a smoothing capacitor, a reactor current detection unit, a bus voltage detection unit, a temperature detection unit, and a control unit. The control unit includes a converter control unit configured to calculate a switching command value for driving the switching element, on the basis of a target command voltage which is the bus voltage to be targeted, the bus voltage detected by the bus voltage detection unit, and the reactor current detected by the reactor current detection unit, and a temperature correction unit configured to correct the temperature of the switching element detected by the temperature detection unit, on the basis of the switching command value calculated by the converter control unit.

Abstract: A power conversion device configured to convert electric power from a power source to a load, the power conversion device including: a voltage boosting device including a boost rectification unit configured to prevent backflow of a current from a side of the load to a side of the power source, the voltage boosting device being configured to change voltage of power from the power source to a predetermined voltage; and a commutation device including a transformer and configured to perform commutation operation, in the commutation operation, the transformer applying a voltage induced by a current flowing through a primary-side winding to a secondary-side winding, which is on an other path different from that for the voltage changing device, wherein the transformer includes at least part of windings that are wound such that an inter-winding distance is uniform.

Abstract: A power conversion apparatus includes a rectifier, a converter including a reactor, a switching element, and a reverse current prevention element, a smoothing capacitor configured to smooth the output voltage, a current detector configured to detect a reactor current, a voltage detector configured to detect the output voltage, and a converter control unit configured to control operation of the switching element of the converter. The converter-control unit includes a switching command calculation unit configured to calculate a switching command value responsive to a ratio of the rectified voltage to the output voltage in accordance with the output voltage and the reactor current, a switching control unit configured to control operation of the switching element in accordance with the switching command value, and a supply abnormality determination unit configured to determine occurrence of a momentary power failure or voltage sag in accordance with the switching command value.

Abstract: A first sheet transfer guide plate includes a first divided sheet guide plate and a second divided sheet guide plate separable from each other. The first divided sheet guide plate is capable of being drawn out or pushed in relative to the second sheet transfer guide plate in a sheet width direction. The first divided sheet guide plate and the second divided sheet guide plate are separable from each other by a draw-out operation or a push-in operation of the first divided sheet guide plate. The first divided sheet guide plate is configured to release nipping of a sheet by paired sheet transfer rollers corresponding to the first divided sheet guide plate, along with the draw-out operation or the push-in operation of the first divided sheet guide plate.

Abstract: A power converter for converting electrical power from a power source to a load, including: a boosting device including a boost rectifier configured to prevent a backflow of a current from the load to the power source, the boosting device being configured to change a voltage of electrical power from the power source to a predetermined voltage; and a commutation device including: a commutation operation device configured to perform a commutation operation of directing a current flowing through the boosting device to an other path; and a commutation rectifier including a plurality of rectifiers and connected in series on the other path, the commutation rectifier being configured to rectify a current relating to commutation, thereby reducing a capacitance component.

Abstract: A backflow preventing device includes a backflow preventing element connected between a power source and a load, for preventing a backflow of a current from the load side to the power source side, a commutation device configured to perform a commutation operation of causing a current to flow through an other path connected in parallel to the backflow preventing element, and a controller configured to change a pulse width of a commutation drive signal for controlling the commutation device to perform the commutation operation based on a current flowing through the backflow preventing element, and transmitting the commutation drive signal having the changed pulse width to the commutation device. The controller transmits the pulse to the commutation device only for a necessary time period so that the commutation device performs the commutation operation, to thereby reduce electric power relating to the commutation operation not contributing to the power conversion.

Abstract: Provided is a power converter for converting electric power between a power source and a load, including: a boosting device including a boost rectifier configured to prevent a backflow of a current from the load side to the power source side, the boosting device being configured to change a voltage of electric power supplied from the power source to a predetermined voltage; a commutation device configured to perform a commutation operation of directing a current flowing through the boosting device to another path; and a controller configured to perform control related to the voltage change of the boosting device and control related to the commutation operation of the commutation device, in which the commutation device is configured to flow, when the commutation device performs the commutation operation, a current generating a voltage causing reverse recovery of the boost rectifier to the commutation device side.

Abstract: When a face of a paper sheet to be discharged on which an image is formed faces downward, a paper discharge device divides an image region of image data on the paper sheet to be discharged into areas along a discharge direction, detects an area in which maximum image density for each divided area is higher than or equal to a specified threshold, and controls a discharge angle so that the detected area does not come into contact with a stacked paper sheet until the paper sheet to be discharged has been discharged from a discharge roller.

Abstract: A paper discharge device including discharge rollers that discharge a paper sheet and a paper discharge tray on which discharged paper sheets are stacked further includes a control unit that controls the discharge angle of a paper sheet according to at least the stacked amount of paper sheets that are stacked on the paper discharge tray so that the position at which the front end of a paper sheet to be discharged begins to come into contact with the stacked paper sheets on the paper discharge tray is within a specified range from the front end of the stacked paper sheets.

Abstract: A first sheet transfer guide plate includes a first divided sheet guide plate and a second divided sheet guide plate separable from each other. The first divided sheet guide plate is capable of being drawn out or pushed in relative to the second sheet transfer guide plate in a sheet width direction. The first divided sheet guide plate and the second divided sheet guide plate are separable from each other by a draw-out operation or a push-in operation of the first divided sheet guide plate. The first divided sheet guide plate is configured to release nipping of a sheet by paired sheet transfer rollers corresponding to the first divided sheet guide plate, along with the draw-out operation or the push-in operation of the first divided sheet guide plate.

Abstract: An air conditioner includes: an outdoor fan provided in an outdoor unit; a permanent magnet synchronous motor that drives the outdoor fan; an inverter that uses a DC power source as a power source and applies a voltage to the permanent magnet synchronous motor; an inverter control means that controls the output voltage of the inverter; and a shunt resist connected between the DC power source and the inverter. If the outdoor fan is rotating due to an external force while the inverter is stopped, the inverter control means causes the inverter to operate using a brake sequence that brakes the rotation of the outdoor fan, and then causes the inverter to operate using a drive sequence that power-drives the outdoor fan.

Abstract: An enveloping machine includes a first feed path for feeding an envelope sheet, a second feed path for feeding a content sheet, a feed roller mechanism disposed on the first feed path and provided with nip rollers for feeding the envelope sheet, an insertion and seal unit disposed downstream from a confluent point of the first and second feed paths for inserting the content sheet into the folded envelope sheet and then sealing the folded envelope sheet, a position correction unit disposed upstream from the confluent point for correcting a lateral position of the envelope sheet, and a controller. The controller controls the feed roller mechanism to hold the envelope sheet by the nip rollers, and concurrently controls the position correction unit to shift the envelope sheet laterally to a predetermined lateral position. According to the enveloping machine, time required for position correction of the envelope sheet can be shortened.

Abstract: When the width of an envelope has sufficient margin for the width of a paper sheet, the aligning operation is skipped to improve productivity. As shown in FIG. 2, in an aligning apparatus 1 including an aligning unit 4 that aligns both side edges of the conveyed paper sheets, a difference value and a predetermined threshold value for use in an aligning operation execution determination are compared. The difference value is calculated by subtracting width dimension obtained from sheet size information of the paper sheet to be aligned from width dimension obtained from envelope size information of the envelope to enclose the paper sheet. The controller 7 controls not to execute the aligning operation if the difference value exceeds the predetermined threshold value.