Abstract: A motor control device includes: a noise reduction unit that sets a PWM count in units of PWM cycles for each PWM cycle in a current control cycle such that a current that flows through a frame ground because of a phase voltage for any one of three phases is canceled out with a current that flows through the frame ground because of a phase voltage for one of the two other phases in each PWM cycle in the current control cycle; and a noise canceling circuit configured to generate a current that is opposite in phase to a current that flows through the frame ground because of a phase voltage for the other of the two other phases in each PWM cycle in the current control cycle.

Abstract: A joint device includes a regulation device, a heating device, and a transparent portion. The regulation device includes a support base that includes a placement surface, and a regulation member. The heating device applies heat for causing solid phase diffusion at a joint interface between the two metal members by radiating an electromagnetic beam to a beam irradiated region via the regulation member. The beam irradiated region is set on a surface of one of the two metal members that is farther from the placement surface while the regulation device regulates motion of the two metal members. The transparent portion is provided at least at a portion corresponding to the beam irradiated region of the metal member to which the electromagnetic beam is irradiated, to transmit the electromagnetic beam.

Abstract: A motor controller includes a motor drive circuit, a noise cancellation circuit, and a control unit. The motor drive circuit supplies electric power to an electric motor. The noise cancellation circuit includes an RLC circuit, a switch element, and a pull-down resistor. One end of the RLC circuit is electrically connected to a positive terminal of a power supply via the switch element, and the other end of the RLC circuit is electrically connected to a frame ground. A connection point between the RLC circuit and the switch element is electrically connected to a negative terminal of the power supply via the pull-down resistor. The control unit turns ON the switch element for a predetermined time at falling timings of phase voltages output from the motor drive circuit.

Abstract: Provided are a welding apparatus having a reduced size. A welding apparatus includes a support base having a placement surface, and a restriction member. A substrate with a semiconductor element disposed thereon is placed on the placement surface such that a surface electrode of the semiconductor element faces upward. A wiring member is placed on the surface electrode. The restriction member restricts movement of the surface electrode and the wiring member in the directions away from each other, by holding the substrate with the semiconductor element disposed thereon and the wiring member, between the placement surface and the restriction member. The welding apparatus further includes a laser device. The laser device locally heats a welding interface between the surface electrode and the wiring member by irradiating a laser beam onto the surface of the wiring member through a hole in the restriction member.

Abstract: A motor control device includes: a noise reduction unit that sets a PWM count in units of PWM cycles for each PWM cycle in a current control cycle such that a current that flows through a frame ground because of a phase voltage for any one of three phases is canceled out with a current that flows through the frame ground because of a phase voltage for one of the two other phases in each PWM cycle in the current control cycle; and a noise canceling circuit configured to generate a current that is opposite in phase to a current that flows through the frame ground because of a phase voltage for the other of the two other phases in each PWM cycle in the current control cycle.

Abstract: A motor controller includes a motor drive circuit, a noise cancellation circuit, and a control unit. The motor drive circuit supplies electric power to an electric motor. The noise cancellation circuit includes an RLC circuit, a switch element, and a pull-down resistor. One end of the RLC circuit is electrically connected to a positive terminal of a power supply via the switch element, and the other end of the RLC circuit is electrically connected to a frame ground. A connection point between the RLC circuit and the switch element is electrically connected to a negative terminal of the power supply via the pull-down resistor. The control unit turns ON the switch element for a predetermined time at falling timings of phase voltages output from the motor drive circuit.

Abstract: When supply of electric power to an inverter using a normally-ON switching element is abnormally stopped, a flow of a current to the switching element of the inverter is reduced. An inverter circuit includes an inverter having at least one arm including two normally-ON switching elements connected in series between two lines to which a voltage of a power supply is applied, a smoothing capacitor connected between the two lines at a position between the power supply and the inverter, and a normally-OFF relay connected into the first line out of the two lines at a position between the smoothing capacitor and the inverter.