Abstract: A laser diode-driving power supply includes a constant current source that supplies current to LDs, a switching element connected in parallel to the LDs, and a control unit that controls the constant current source and performs on-off control of the switching element. The control unit compares a first current command value and a second current command value for controlling current output from the constant current source, and when the second current command value input after the first current command value is smaller than the first current command value, applies to the LDs a voltage in the range of a voltage at which current flows through the LDs to a voltage less than the lasing threshold of the LDs when there is no output from the LDs.

Abstract: A laser diode-driving power supply includes a constant current source that supplies current to LDs, a switching element connected in parallel to the LDs, and a control unit that controls the constant current source and performs on-off control of the switching element. The control unit compares a first current command value and a second current command value for controlling current output from the constant current source, and when the second current command value input after the first current command value is smaller than the first current command value, applies to the LDs a voltage in the range of a voltage at which current flows through the LDs to a voltage less than the lasing threshold of the LDs when there is no output from the LDs.

Abstract: A planar transformer includes a plurality of EI cores, a primary winding board provided with primary windings each surrounding a corresponding one of the EI cores, a first secondary winding board provided with secondary windings each surrounding a corresponding one of the EI cores, and a second secondary winding board provided with secondary windings each surrounding a corresponding one of the EI cores. The primary winding board, the first secondary winding board, and the second secondary winding board are layered in a spaced relation to each other.

Abstract: A series connection body wherein a first backflow prevention elements, a second backflow prevention element, a first switching element and a second switching element are connected in series in this order; a reactor; a first output capacitor connected between a first end of the series connection body and a second end of the series connection body; and a second output capacitor connected between a connection point between the first switching element and the second switching element and a connection point between the first backflow prevention element and the second backflow prevention element are provided, a DC is inputted between an end of the reactor and the second end section of the series connection body, and power is supplied to a first load connected to both ends of the first output capacitor and a second load connected to both ends of the second output capacitor.

Abstract: A refrigeration cycle apparatus includes: a refrigerant circuit, a use side heat exchanger, a pressure reducing device, and a heat source side heat exchanger; A fan is provided together with at least one, selected from between, the use side heat exchanger and the heat source side heat exchanger and that has a fan motor; a relay unit connected to a direct-current supply device via the direct-current circuit breaker; a resistor unit connected in parallel to the relay unit; a DC/AC converter configured to convert a direct-current voltage supplied from the direct-current supply device via either the relay unit or the resistor unit into an alternating-current voltage and to supply the alternating-current voltage to at least one, selected from between, the compressor motor and the fan motor; and an opening and closing control unit configured to bring the relay unit into an open state when the direct-current circuit breaker becomes open.

Abstract: Provided is an electrostatic capacitance detection device including: an electrode pair including a pair of electrodes, the electrode pair being arranged inside a compressor configured to compress refrigerant; a capacitor being connected in series to the electrode pair; an inverter having one of power lines connected to one end of series-connected electrode pair and capacitor, and is configured to drive the compressor, the power lines being used for driving the compressor; and a voltage detecting unit configured to measure a voltage between the pair of electrodes of the electrode pair.

Abstract: A power conversion device is provided that includes a rectifier, a booster circuit configured to boost an output voltage of the rectifier, a smoothing capacitor configured to smooth an output voltage of the booster circuit, and an inverter circuit configured to convert a DC voltage of the smoothing capacitor to an AC voltage and drive a motor forming a part of a device supplied with the voltage after the conversion. In addition, a reactor, a first backflow prevention element, a second backflow prevention element, a first switching element, a second switching element, an intermediate capacitor, and a controller configured to control the first switching element and the second switching element, are included.

Abstract: A power conversion apparatus, including: an MLC circuit configured to boost an input voltage from a three-phase rectifier; a smoothing capacitor configured to smooth an output of the MLC circuit; an inverter control unit configured to generate a PWM signal; an inverter circuit configured to convert a DC voltage of the smoothing capacitor into an AC voltage based on an input of the PWM signal and to supply the AC voltage to a motor; a boost mode switching unit having at least three boost modes in which a boost level of the input voltage is selected and configured to switch among the at least three boost modes depending on an operation status of the motor determined for the purpose of controlling a refrigeration cycle; and an MLC control unit configured to control the MLC circuit based on the switching by the boost mode switching unit.

Abstract: A refrigeration cycle apparatus includes: a refrigerant circuit, a use side heat exchanger, a pressure reducing device, and a heat source side heat exchanger; A fan is provided together with at least one, selected from between, the use side heat exchanger and the heat source side heat exchanger and that has a fan motor; a relay unit connected to a direct-current supply device via the direct-current circuit breaker; a resistor unit connected in parallel to the relay unit; a DC/AC converter configured to convert a direct-current voltage supplied from the direct-current supply device via either the relay unit or the resistor unit into an alternating-current voltage and to supply the alternating-current voltage to at least one, selected from between, the compressor motor and the fan motor; and an opening and closing control unit configured to bring the relay unit into an open state when the direct-current circuit breaker becomes open.

Abstract: A rectifier, a booster circuit configured to boost an output voltage of the rectifier, a smoothing capacitor configured to smooth an output voltage of the booster circuit, and an inverter circuit configured to convert a DC voltage of the smoothing capacitor to an AC voltage and drive a motor forming a part of a device supplied with the voltage after the conversion, are included. In addition, a reactor, a first backflow prevention element, a second backflow prevention element, a first switching element, a second switching element, an intermediate capacitor, and a controller configured to control the first switching element and the second switching element, are included.

Abstract: A power conversion apparatus, including: an MLC circuit configured to boost an input voltage from a three-phase rectifier; a smoothing capacitor configured to smooth an output of the MLC circuit; an inverter control unit configured to generate a PWM signal; an inverter circuit configured to convert a DC voltage of the smoothing capacitor into an AC voltage based on an input of the PWM signal and to supply the AC voltage to a motor; a boost mode switching unit having at least three boost modes in which a boost level of the input voltage is selected and configured to switch among the at least three boost modes depending on an operation status of the motor determined for the purpose of controlling a refrigeration cycle; and an MLC control unit configured to control the MLC circuit based on the switching by the boost mode switching unit.

Abstract: Feedback control of an object which moves back and forth in a straight line along a linear guide is performed through PID control. A parameter adjustment unit which determines the control parameters to be used for PID control performs feedback control and determines the optimal value of control parameters by means of an evaluation function based on the error between the measured value of the current velocity and the target velocity, for the control parameters of maximum reverse voltage and at least one from among proportional coefficient (CP), differential coefficient CD), integral coefficient CI), and frictional coefficient (CF).

Abstract: An electric discharge machining apparatus includes: electrodes the total quantity of which is equal to N; an alternating-current power source; and capacitors the total quantity of which is equal to N. The alternating-current power source applies an alternating voltage commonly to the electrodes. One end of each of the capacitors is connected to a corresponding one of the electrodes, whereas the other ends of the capacitors are commonly connected to the alternating-current power source.

Abstract: An electric discharge machining apparatus includes: electrodes E1 to En the total quantity of which is equal to N; an alternating-current power source G; and capacitors C1 to Cn the total quantity of which is equal to N. The alternating-current power source G applies an alternating voltage commonly to the electrodes E1 to En. One end of each of the capacitors C1 to Cn is connected to a corresponding one of the electrodes E1 to En, whereas the other ends of the capacitors C1 to Cn are commonly connected to the alternating-current power source G.

Abstract: Feedback control of an object which moves back and forth in a straight line along a linear guide is performed through PID control. A parameter adjustment unit which determines the control parameters to be used for PID control performs feedback control and determines the optimal value of control parameters by means of an evaluation function based on the error between the measured value of the current velocity and the target velocity, for the control parameters of maximum reverse voltage and at least one from among proportional coefficient (CP), differential coefficient CD), integral coefficient CI), and frictional coefficient (CF).

Abstract: In a power converting apparatus which converts AC power into DC power, an inverter circuit including at least one series-connected single-phase inverter is connected in a downstream of a stage in which an AC input is rectified in series therewith. In the downstream stage of the inverter circuit, there are provided a smoothing capacitor connected via a rectifier diode and a short-circuiting switch for bypassing the smoothing capacitor. The short-circuiting switch is set to an ON state only in each of short-circuiting phase ranges of which midpoint matches each of zero-crossing phases and an output of the inverter circuit is controlled by using a current command so that a DC voltage of the smoothing capacitor follows a target voltage and an input power factor is improved.

Abstract: A power converting apparatus includes a first inverter circuit including a high-voltage first DC voltage source and operated at a low frequency using Si IGBTs having a high withstand voltage exceeding 1000 V and a second inverter circuit including a low-voltage capacitor operated by high-frequency PWM using SiC MOSFETs having a low withstand voltage, wherein an AC side of the first inverter circuit is connected in series to an AC side of the second inverter circuit. The power converting apparatus outputs AC power having a prescribed voltage waveform obtained from the sum of voltages generated by the first and second inverter circuits.

Abstract: A power converting apparatus includes a main inverter having a high-voltage DC power supply that operates at a low frequency employing SiC MOSFETs having a high withstand voltage exceeding 600 V and a sub-inverter having a low-voltage capacitor that operates through high-frequency PWM employing Si MOSFETs having a low withstand voltage. With AC sides of the main inverter and the sub-inverter connected in series, the power converting apparatus outputs AC power having a prescribed voltage waveform by adding voltages individually generated by the main inverter and the sub-inverter. Specifically, the SiC MOSFETs are used only in the main inverter of which devices are required to have a high withstand voltage and the Si MOSFETs are used in the sub-inverter of which devices may have a relatively low withstand voltage, whereby conduction loss is reduced with an inexpensive circuit configuration.

Abstract: In a power conversion device which performs DC/DC conversion, an inverter circuit (20), which is formed of one or more single-phase inverters (20a) and (20b) connected in series to each other, is connected in series to a DC power supply (1) in its subsequent stage. In further subsequent stage, a smoothing capacitor (6) connected to the inverter circuit (20) via a rectifier diode (5), and a shorting switch (4) which bypasses the smoothing capacitor (6) are provided. The shorting switch (4) is switched ON to charge capacitors (25) and (35) included in the single-phase inverter (20a) and (20b), respectively, whereas the shorting switch (4) is switched OFF to discharge the capacitors (25) and (35), whereby the voltage of the smoothing capacitor (6) is controlled.

Abstract: In a power conversion apparatus that converts AC power to DC power, an inverter circuit including one or more single-phase inverters connected in series with each other is connected in series at the subsequent stage of a rectification of an AC input. At the subsequent stage of the inverter circuit, a smoothing capacitor connected via a rectification diode, and a short-circuiting switch for bypassing the smoothing capacitor are provided. The short-circuiting switch is subjected to ON/OFF control by PWM control such that a voltage of the DC voltage supply of the inverter circuit follows a target voltage. The inverter circuit is subjected to output control such that a DC voltage of the smoothing capacitor follows a target voltage and an input power factor is improved.