Abstract: An electric motor drive device includes a booster circuit, an inverter, a connection switching device, and first and second control devices. The booster circuit boosts a voltage value of a bus voltage to be applied to a DC bus. The bus voltage is applied to the inverter, and the inverter applies an AC voltage having a variable frequency and a variable voltage value to an electric motor. The connection switching device switches a connection state of windings of the electric motor. The second control device performs zero current control to control the inverter such that a current flowing through the electric motor or the connection switching device is zero. When operating the connection switching device to switch the connection state, the second control device performs the zero current control after a boosting operation of the booster circuit is stopped by the first control device.

Abstract: A direct-current power supply includes: a rectifier circuit in which switching elements are bridge-connected; a reactor; a gate circuitry that drives the switching elements; and a gate circuitry that drives the switching elements. A connection point between the switching element and the switching element is connected to an alternating-current power supply via the reactor, and a connection point between the switching element and the switching element is connected to the alternating-current power supply without via the reactor. A time during which the gate circuitry turns on the switching elements is longer than a time during which the gate circuitry turns on the switching elements.

Abstract: Coaxial connector including a center conductor provided inside an outer conductor with a tubular outer conductor main body. A mating portion on one side in the axial direction of the outer conductor main body detachably mates with a counterpart connector. A supporting portion on the other side in the axial direction of the outer conductor main body supports the center conductor through the insulating member medium. Securing portions projecting from the end face on the other side in the axial direction or from the outer peripheral surface on the other side in the axial direction of the outer conductor main body towards the other side in the axial direction securing the outer conductor by soldering to a conductor pattern on the board surface. A first barrier portion on the outer peripheral surface on the other side in the axial direction of the outer conductor main body blocks solder flow.

Abstract: Coaxial connector including a center conductor provided inside an outer conductor with a tubular outer conductor main body. A mating portion on one side in the axial direction of the outer conductor main body detachably mates with a counterpart connector. A supporting portion on the other side in the axial direction of the outer conductor main body supports the center conductor through the insulating member medium. Securing portions projecting from the end face on the other side in the axial direction or from the outer peripheral surface on the other side in the axial direction of the outer conductor main body towards the other side in the axial direction securing the outer conductor by soldering to a conductor pattern on the board surface. A first barrier portion on the outer peripheral surface on the other side in the axial direction of the outer conductor main body blocks solder flow.