Abstract: The invention is related to a device for detecting insulation degradation in an inverter-driven load device, in particular a motor, the device including: zero-phase current measuring means for measuring a zero-phase current in power-feed lines, provided in the power-feed lines between an inverter device and the motor; and command control means for putting rotation of the motor on standby; wherein the zero-phase current measuring means measures the total of phase currents fed into respective phases so as not to rotate a shaft even when an external force is applied to the shaft during the rotation being on standby, whereby allowing regular detection of insulation degradation without switching over the power-feed lines connected with the load device.

Abstract: In a magnetic position sensor, first and second detecting cores are disposed so as to line up with each other on opposite sides of a detecting gap. A magnet unit is displaced relative to the first and second detecting cores together with displacement of a measured object. The magnet unit has: first and second magnet cores that are disposed so as to line up with each other on opposite sides of an origin gap; and a magnet that generates two magnetic flux loops between the first and second detecting cores and the first and second magnet cores, the magnetic flux loops having a boundary at the origin gap.

Abstract: A core is divided by alternately arranging plural magnetic material portions and plural non-magnetic material portions in a circumferential direction of the core through which a primary conductor penetrates. A conductor is wound around the core under conditions in which each core cross section of the core intersects the magnetic material portion and the non-magnetic material portion, each core cross section including a cut end surface of each conductor of a secondary winding wound around the core, and a ratio of a magnetic material portion cross-sectional area of the magnetic material portion to a non-magnetic material portion cross-sectional area of the non-magnetic material portion at the core cross section is kept constant at each core cross section.

Abstract: A core is divided by alternately arranging plural magnetic material portions and plural non-magnetic material portions in a circumferential direction of the core through which a primary conductor penetrates. A conductor is wound around the core under conditions in which each core cross section of the core intersects the magnetic material portion and the non-magnetic material portion, each core cross section including a cut end surface of each conductor of a secondary winding wound around the core, and a ratio of a magnetic material portion cross-sectional area of the magnetic material portion to a non-magnetic material portion cross-sectional area of the non-magnetic material portion at the core cross section is kept constant at each core cross section.