Abstract: In an electronic device, a stay is fixed to a surface of a heatsink on the side of a substrate or to a side surface of the heatsink, and is also fixed to the substrate. A contact portion of the stay which is in contact with the heatsink is in contact with the heatsink by mating therewith. The electron device is further provided with a fastening member for fixing the contact potion to the heatsink in detachable manner.

Abstract: The rectifier includes: a main circuit unit configured to perform power conversion between AC power on a side of a three-phase AC power supply and DC power on a DC side by rectifying operation of a rectifying device and ON-OFF operation of a switching device; a power calculation unit configured to calculate a value of a power flowing between the side of the three-phase AC power supply and the DC side via the main circuit unit; and a control unit configured to perform control to execute the ON-OFF operation of the switching device, wherein the control unit changes a length of an ON period per cycle in the ON-OFF operation executed on the switching device according to the value of the power calculated by the power calculation unit.

Abstract: A power conversion apparatus includes: a converter converting AC voltage supplied from an AC power supply via a switch unit, into DC voltage; a smoothing capacitor smoothing the DC voltage output from the converter; a resistor suppressing electric current flowing into the smoothing capacitor; a switch short-circuiting the both ends of the resistor; a filter including reactors and capacitors and that removes noise; and a control unit controlling opening and closing of the switch unit and the switch. The control unit changes the switch unit from the open state to the closed state with the switch in an open state if the voltage across the smoothing capacitor is lower than a voltage threshold, and changes the switch unit from the open state to the closed state with the switch in an closed state if the voltage across the smoothing capacitor is equal to or greater than the voltage threshold.

Abstract: A rectifier according to an aspect of the present disclosure includes: a bridge circuit that derives a positive voltage component and a negative voltage component from an AC power supply voltage; a smoothing capacitor that smooths an output voltage from the bridge circuit; a pre-charge resistor that is provided between the bridge circuit and the smoothing capacitor, and reduces an inrush current; a charge switch that is provided in parallel with the pre-charge resistor; and a controller that controls the charge switch between an open state and a close state, wherein when application of the AC power supply voltage to the bridge circuit is started, the controller closes the charge switch if a voltage applied between ends of the pre-charge resistor is determined to become equal to or lower than a predetermined resistor threshold voltage.

Abstract: The rectifier includes: a main circuit unit configured to perform power conversion between AC power on a side of a three-phase AC power supply and DC power on a DC side by rectifying operation of a rectifying device and ON-OFF operation of a switching device; a power calculation unit configured to calculate a value of a power flowing between the side of the three-phase AC power supply and the DC side via the main circuit unit; and a control unit configured to perform control to execute the ON-OFF operation of the switching device, wherein the control unit changes a length of an ON period per cycle in the ON-OFF operation executed on the switching device according to the value of the power calculated by the power calculation unit.

Abstract: A motor drive apparatus includes a converter which converts AC power into DC power and outputs it to a DC link, an inverter which converts the DC power of the DC link into AC power for driving a motor, DC link capacitors connected in series with each other, resistors connected in parallel with the DC link capacitors and connected in series with each other, a DC link voltage detection unit, a current-carrying element which is connected between one of connection points connecting the DC link capacitors to each other and one of connection points connecting the resistors to each other, and carries a current when the applied voltage is higher than a predetermined value, and a short-circuit judgment unit which judges that at least one of the DC link capacitors has shorted when the DC link voltage value is larger than an upper limit or smaller than a lower limit.

Abstract: A power conversion apparatus includes: a converter converting AC voltage supplied from an AC power supply via a switch unit, into DC voltage; a smoothing capacitor smoothing the DC voltage output from the converter; a resistor suppressing electric current flowing into the smoothing capacitor; a switch short-circuiting the both ends of the resistor; a filter including reactors and capacitors and that removes noise; and a control unit controlling opening and closing of the switch unit and the switch. The control unit changes the switch unit from the open state to the closed state with the switch in an open state if the voltage across the smoothing capacitor is lower than a voltage threshold, and changes the switch unit from the open state to the closed state with the switch in an closed state if the voltage across the smoothing capacitor is equal to or greater than the voltage threshold.

Abstract: A rectifier according to an aspect of the present disclosure includes: a bridge circuit that derives a positive voltage component and a negative voltage component from an AC power supply voltage; a smoothing capacitor that smooths an output voltage from the bridge circuit; a pre-charge resistor that is provided between the bridge circuit and the smoothing capacitor, and reduces an inrush current; a charge switch that is provided in parallel with the pre-charge resistor; and a controller that controls the charge switch between an open state and a close state, wherein when application of the AC power supply voltage to the bridge circuit is started, the controller closes the charge switch if a voltage applied between ends of the pre-charge resistor is determined to become equal to or lower than a predetermined resistor threshold voltage.

Abstract: A motor driving device includes a printed board on which a pattern is printed, and a resin board which is formed by molding a resin and on which no pattern is printed, and the printed board is provided on the resin board.

Abstract: A motor driving device includes a heat sink, a rectifier provided on the heat sink and configured to rectify an AC voltage supplied from an AC power supply to a DC voltage, a charging resistor provided on the heat sink and configured to be used for charging a smoothing capacitor for smoothing the DC voltage rectified by the rectifier, and a temperature sensor with which the charging resistor is provided.

Abstract: A motor control device includes a rectifier which converts AC power into DC power and outputs it to a DC link, an inverter which converts the DC power of the DC link into AC power for each motor and outputs it, an AC voltage detection unit which detects an AC voltage value on the AC input side of the rectifier, a state determination unit which determines that a voltage dropped state has been set when the AC voltage value is smaller than a certain specified voltage and that a normal state has been set when the AC voltage value is equal to or larger than the specified voltage, and an output control unit which controls each motor in accordance with the amount of voltage drop with respect to the specified voltage of the AC voltage value when the state determination unit determines that the voltage dropped state has been set.

Abstract: A motor drive device capable of attaching a fan unit to a mounting member more easily. The motor drive device includes the mounting member formed with a mounting hole, the fan unit including a lid positioned facing the mounting member to cover the mounting hole and being fixed to the mounting member, and a restricting member movably attached to the lid, the restricting member being movable between a restriction position for engaging with the mounting member and a non-restriction position for releasing from the mounting member.

Abstract: A motor drive apparatus includes a PWM converter configured to convert AC power of an AC power supply into DC power, a DC link unit including capacitors provided on the DC output side of the PWM converter and connected in series with each other, an inverter configured to convert the DC power of the DC link unit into AC power for driving a motor and output the AC power, a DC link voltage detection unit, a power supply voltage detection unit, a short-circuit judgment unit configured to judge that at least one of the capacitors has shorted when the DC link voltage value is smaller than the peak value of the power supply voltage, and a shut-off unit configured to shut off flow of AC power from the AC power supply into the PWM converter when the short-circuit judgment unit judges that at least one of the capacitors has shorted.

Abstract: A motor drive apparatus includes a converter which converts AC power into DC power and outputs it to a DC link, an inverter which converts the DC power of the DC link into AC power for driving a motor, DC link capacitors connected in series with each other, resistors connected in parallel with the DC link capacitors and connected in series with each other, a DC link voltage detection unit, a current-carrying element which is connected between one of connection points connecting the DC link capacitors to each other and one of connection points connecting the resistors to each other, and carries a current when the applied voltage is higher than a predetermined value, and a short-circuit judgment unit which judges that at least one of the DC link capacitors has shorted when the DC link voltage value is larger than an upper limit or smaller than a lower limit.

Abstract: A motor driving device includes a heat sink, a rectifier provided on the heat sink and configured to rectify an AC voltage supplied from an AC power supply to a DC voltage, a charging resistor provided on the heat sink and configured to be used for charging a smoothing capacitor for smoothing the DC voltage rectified by the rectifier, and a temperature sensor with which the charging resistor is provided.

Abstract: A motor drive apparatus includes a PWM converter configured to convert AC power of an AC power supply into DC power, a DC link unit including capacitors provided on the DC output side of the PWM converter and connected in series with each other, an inverter configured to convert the DC power of the DC link unit into AC power for driving a motor and output the AC power, a DC link voltage detection unit, a power supply voltage detection unit, a short-circuit judgment unit configured to judge that at least one of the capacitors has shorted when the DC link voltage value is smaller than the peak value of the power supply voltage, and a shut-off unit configured to shut off flow of AC power from the AC power supply into the PWM converter when the short-circuit judgment unit judges that at least one of the capacitors has shorted.

Abstract: A motor driving device includes a printed board on which a pattern is printed, and a resin board which is formed by molding a resin and on which no pattern is printed, and the printed board is provided on the resin board.

Abstract: A motor drive device that inputs AC power from a power supply to drive a motor includes: a converter that converts the AC power from the power supply into DC power; a DC/DC converter that generates DC power produced by stepping-up, stepping-down, or stepping-up and stepping-down the DC power from the converter; an inverter that converts the DC power from the DC/DC converter into AC power and supplies to the motor; and an electrical storage capacitor that is provided between the DC/DC converter and the inverter.

Abstract: A motor drive device capable of attaching a fan unit to a mounting member more easily. The motor drive device includes the mounting member formed with a mounting hole, the fan unit including a lid positioned facing the mounting member to cover the mounting hole and being fixed to the mounting member, and a restricting member movably attached to the lid, the restricting member being movable between a restriction position for engaging with the mounting member and a non-restriction position for releasing from the mounting member.

Abstract: A motor control device includes a rectifier which converts AC power into DC power and outputs it to a DC link, an inverter which converts the DC power of the DC link into AC power for each motor and outputs it, an AC voltage detection unit which detects an AC voltage value on the AC input side of the rectifier, a state determination unit which determines that a voltage dropped state has been set when the AC voltage value is smaller than a certain specified voltage and that a normal state has been set when the AC voltage value is equal to or larger than the specified voltage, and an output control unit which controls each motor in accordance with the amount of voltage drop with respect to the specified voltage of the AC voltage value when the state determination unit determines that the voltage dropped state has been set.