Abstract: A first drive circuit is connected to a first end of a primary winding of a pulse transformer. A second drive circuit is connected to a second end of the primary winding of the pulse transformer. A voltage clamp unit clamps a voltage of a semiconductor element at a specified voltage when a voltage output from a secondary winding of the pulse transformer is negative. A current detection circuit detects current flowing through the semiconductor element and outputs a detection signal. A control circuit controls the first drive circuit and the second drive circuit based on the detection signal. A current limiting circuit imposes a limit on current flowing through the primary winding of the pulse transformer based on the detection signal.

Abstract: A laser beam generation device includes power supply units, LD modules, a combiner, and a control device. The LD modules receive currents from the power supply units, and output laser beams. The combiner collects the laser beams and outputs one laser beam. The control device generates control signals such that power of the laser beam becomes a laser output setting value and such that the currents become current command values. Phases of pulses of the control signals are shifted from each other by 60 degrees.

Abstract: A laser diode driving power source of a laser machining device that radiates laser light emitted from an LD to a workpiece to machine the workpiece includes a power converter including a switching device, to supply a current to the LD, and a control unit to control a switching operation of the switching device. A value smaller than a value that is n times a time constant for laser machining is set as a switching period of the switching device in the control unit, the n is larger than 1, and the time constant for laser machining is a value obtained by dividing a surface roughness required for machining of the workpiece by a moving velocity of the workpiece.

Abstract: A power conversion device that provides high heat dissipation and is easy to assemble. A power conversion device includes: a first heat dissipator; a second heat dissipator; a printed board having a first circuit pattern formed thereon; a first insulating member provided between first heat dissipator and printed board; a switching element including an electrode portion electrically bonded to first circuit pattern with a first bonding member interposed therebetween; a first fixing member bonded to an exposed surface of electrode portion; a heat dissipating member having one end bonded to first fixing member, and the other end provided between the switching element and second heat dissipator; a second insulating member sandwiched between second heat dissipator and switching element; and an installation portion.

Abstract: A laser diode driving power source of a laser machining device that radiates laser light emitted from an LD to a workpiece to machine the workpiece includes a power converter including a switching device, to supply a current to the LD, and a control unit to control a switching operation of the switching device. A value smaller than a value that is n times a time constant for laser machining is set as a switching period of the switching device in the control unit, the n is larger than 1, and the time constant for laser machining is a value obtained by dividing a surface roughness required for machining of the workpiece by a moving velocity of the workpiece.

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: In a power converter apparatus, a first power converter circuit is configured of first power semiconductor devices, and a second power converter circuit is connected in parallel to the first power converter circuit, and is configured of second power semiconductor devices. A control circuit generates a control signal for controlling each power semiconductor device of the first and second power converter circuits. A timing control signal generator circuit compares a first amount of current flowing through the first power semiconductor devices with a second amount of current flowing through the second power semiconductor devices, and generate a timing control signal for controlling a timing of a rise or a fall of each of the control signals inputted to the first and second power converter circuits, based on a comparison result. A timing correction circuit controls the control signals to correct the timing of the rise or the fall thereof.

Abstract: In a power converter apparatus, a first power converter circuit is configured of first power semiconductor devices, and a second power converter circuit is connected in parallel to the first power converter circuit, and is configured of second power semiconductor devices. A control circuit generates a control signal for controlling each power semiconductor device of the first and second power converter circuits. A timing control signal generator circuit compares a first amount of current flowing through the first power semiconductor devices with a second amount of current flowing through the second power semiconductor devices, and generate a timing control signal for controlling a timing of a rise or a fail of each of the control signals inputted to the first and second power converter circuits, based on a comparison result. A timing correction circuit controls the control signals to correct the timing of the rise or the fall thereof.

Abstract: By reduction in loss and noise of a three-phase reactor on the AC side of an electric power converter, compactness and reduction in weight of the reactor are realized, and countermeasures for heat and noise are reduced, and a specific frequency component is reduced, thus cost reduction and conversion efficiency are improved, and carriers of a controller are prepared in correspondence to the phases of the electric power converter, and moreover a phase difference of each carrier is set properly.

Abstract: By reduction in loss and noise of a three-phase reactor on the AC side of an electric power converter, compactness and reduction in weight of the reactor are realized, and countermeasures for heat and noise are reduced, and a specific frequency component is reduced, thus cost reduction and conversion efficiency are improved, and carriers of a controller are prepared in correspondence to the phases of the electric power converter, and moreover a phase difference of each carrier is set properly.

Abstract: By reduction in loss and noise of a three-phase reactor on the AC side of an electric power converter, compactness and reduction in weight of the reactor are realized, and countermeasures for heat and noise are reduced, and a specific frequency component is reduced, thus cost reduction and conversion efficiency are improved, and carriers of a controller are prepared in correspondence to the phases of the electric power converter, and moreover a phase difference of each carrier is set properly.

Abstract: By reduction in loss and noise of a three-phase reactor on the AC side of an electric power converter, compactness and reduction in weight of the reactor are realized, and countermeasures for heat and noise are reduced, and a specific frequency component is reduced, thus cost reduction and conversion efficiency are improved, and carriers of a controller are prepared in correspondence to the phases of the electric power converter, and moreover a phase difference of each carrier is set properly.

Abstract: By reduction in loss and noise of a three-phase reactor on the AC side of an electric power converter, compactness and reduction in weight of the reactor are realized, and countermeasures for heat and noise are reduced, and a specific frequency component is reduced, thus cost reduction and conversion efficiency are improved, and carriers of a controller are prepared in correspondence to the phases of the electric power converter, and moreover a phase difference of each carrier is set properly.