Current sensor
A current sensor includes units each of which has a bus bar through which current flows, a magnetic sensor facing one of plate surfaces of the bus bar, a shield facing the other plate surface. The units have a large-current unit and a small-current unit. A first distance between the bus bar and the magnetic sensor in a normal direction of the plate surfaces of the bus bar is the same as a distance L 1 A of the large-current unit and a distance L 1 B of the small-current unit. Since, as for a second distance between the bus bar and a base of the shield, a distance L 2 A of the large-current unit is larger than a distance L 2 B of the small-current unit, a measurement range of the large-current unit is widened and a measurement error due to magnetic saturation of the shield is suppressed.
1 . A current sensor comprising:
a plurality of units which are integrally formed, each unit including:
a bus bar extending in a first direction and allowing a current to flow therethrough, the bus bar having a flat plate shape with a first plate surface and a second plate surface opposite to the first plate surface in a second direction normal to the first and second plate surfaces;
a magnetic sensor disposed on one side of the bus bar so as to face the first plate surface; and
a shield having a flat base and disposed on the other side of the bus bar such that the flat base faces the second plate surface,
wherein the plurality of units include at least one large-current unit for measuring a first range of current, and at least one small-current unit for measuring a second range of current smaller than the first range of current, the plurality of the units being arranged along a third direction orthogonal to the first direction and the second direction,
wherein a first distance between the bus bar and the magnetic sensor in the second direction in the large-current unit is the same as that in the small-current unit, while a second distance between the bus bar and the flat base in the second direction in the large-current unit is greater than that in the small-current unit,
and wherein two adjacent units for measuring different current ranges are aligned on a same straight line extending in the third direction, and two adjacent units for measuring a same current range are staggered and arranged on different straight lines extending in the third direction.
2 . A current sensor comprising:
a plurality of units which are integrally formed into an arrangement, each unit including:
a bus bar extending in a first direction and allowing a current to flow therethrough, the bus bar having a flat plate shape with a first plate surface and a second plate surface opposite to the first plate surface in a second direction normal to the first and second plate surfaces;
a magnetic sensor disposed on one side of the bus bar so as to face the first plate surface; and
a shield having a flat base disposed on the other side of the bus bar such that the flat base faces the second flat surface,
wherein the plurality of units include a group of large-current units each configured to measure a first range of current, and a group of small-current units each configured to measure a second range of current smaller than the first range of current, and the group of large-current units and the group of small-current units are arranged along a third direction orthogonal to the first direction and the second direction,
wherein a first distance between the bus bar and the magnetic sensor in the second direction in the group of large-current units is the same as that in the group of small-current units, while a second distance between the bus bar and the flat base in the second direction in the group of large-current units is greater than that in the group of small-current units,
wherein the bus bars in the group of large-current units and the bus bars of the group of small-current units are arranged on a same plane,
and wherein adjacent large-current units within the group thereof are staggered and not aligned on a same straight line extending in the third direction, and adjacent small-current units within the group thereof are staggered and not aligned on a same straight line extending in the third direction, while one of the large-current units and one of the small-current units adjacent to each other are aligned on a same straight line extending in the third direction.
3 . A current sensor comprising:
a plurality of units which are integrally formed, each unit including:
a bus bar extending in a first direction and allowing a current to flow therethrough, the bus bar having a flat plate shape with a first plate surface and a second plate surface opposite to the first plate surface in a second direction normal to the first and second plate surfaces;
a magnetic sensor disposed on one side of the bus bar so as to face the first plate surface; and
a shield having a flat base disposed on the other side of the bus bar such that the flat base faces the second flat surface,
wherein the plurality of units include a large-current unit for measuring a first range of current, and a plurality of small-current units each for measuring a second range of current smaller than the first range of current, and the large-current unit and the plurality of small-current units are arranged along a third direction orthogonal to the first direction and the second direction,
wherein a first distance between the bus bar and the magnetic sensor in the second direction in the large-current unit is the same as that in the plurality of small-current units, while a second distance between the bus bar and the base in the second direction in the large-current unit is greater than that in the plurality of small-current units,
wherein the bus bar in the large-current unit and the bus bars in of the plurality of small-current units are arranged on a same plane,
and wherein adjacent small-current units are staggered and not arranged on a same straight line extending in the third direction, and the large-current unit and at least one of the small-current units adjacent thereto are aligned on a same straight line extending in the third direction.
4 . The current sensor according to claim 1 ,
wherein the bus bar of the large-current unit and that of the small-current unit are identical at least in a portion thereof disposed between the magnetic sensor and the shield,
and wherein the magnetic sensor and the shield in the large-current unit are identical to the magnetic sensor and the shield in the small-current unit, respectively.
5 . The current sensor according to claim 1 , wherein the shield in each unit includes a pair of standing portions extending in the second direction toward the magnetic sensor from opposite ends of the base plate in the third direction.
6 . The current sensor according to claim 5 , wherein respective ends of the standing portions of the shield are located between the magnetic sensor and the bus bar in the second direction.
7 . The current sensor according to claim 1 ,
wherein the plurality of units comprises:
a first unit group including a plurality of large-current units arranged at an interval a 1 in the third direction; and
a second unit group disposed adjacent to the first unit group along the third direction, the second unit group including a plurality of small-current units arranged at an interval a 2 in the third direction,
wherein one of the large-current units closest to the second unit group and one of the small-current units closest to the first unit group are adjacent to each other with an interval b which is greater than both of the interval a 1 and the interval a 2 ,
and wherein the bus bars in the plurality of large-current units and the bus bars in the plurality of small-current units are all arranged on a same plane.
8 . The current sensor according to claim 1 , further comprising:
at least one medium-current unit for measuring a third range of current smaller than the first range of current and greater than the second range of current.