Current sensor for wires having different diameters

Patent metadata

Field	Value
Publication number	US-9575094-B2
Application number	US-201314018080-A
Country	US
Kind code	B2
Filing date	Sep 4, 2013
Priority date	Nov 14, 2012
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A current sensor includes a casing including a pair of arms and coupling part, multiple magneto-electric transducers arranged on the circumference of a virtual ellipse whose major axis or minor axis extends between the arms, a support disposed obliquely relative to the major axis or the minor axis of the virtual ellipse within an angle formed by the major axis and the minor axis so as to be close to one of the arms when viewed from the center of a wire disposed and fastened between the arms, and a band wound around a circumferential surface of the wire fastened between the arms, part of the band being caught by the support, the wire being fastened by the band such that the central axis or center of the wire is held close to the support.

First claim

What is claimed is:

1. A current sensor comprising:
a casing including a pair of arms and a connecting portion connecting the arms;
a plurality of magneto-electric transducers accommodated in the casing, the magneto-electric transducers being arranged along a circumference of a virtual ellipse having a first axis and a second axis crossing each other at a center thereof, the first axis being a major axis of the virtual ellipse extending between the arms and coinciding with an intermediate line between the arms, and the second axis being a minor axis of the virtual ellipse, the major axis being longer than the minor axis; and
a fixing member disposed on the casing, the fixing member being arranged obliquely with respect to the first axis viewed from the center of the virtual ellipse, so as to be closer to one of the arms with respect to the first axis; and
a band attached to the fixing member, the band winding around a circumferential surface of a current wire disposed between the arms so as to fasten the current wire such that a center of the current wire is pulled toward the fixing member, whereby the center of the current wire is displaced from the center of the virtual ellipse along a direction oblique to the major axis depending on an outer diameter of the current wire.

2. The current sensor according to claim 1 , wherein the fixing member and the band hold the current wire such that the center of the current wire is displaced in a first direction if the current wire has a different diameter, wherein a change in sensitivity caused by the displacement in the first direction is relatively smaller than that caused by a displacement of the current wire in a direction along the first axis or the second axis of the virtual ellipse.

3. The current sensor according to claim 2 , wherein the fixing member is disposed in a direction angled at 45° from the first axis towards the one of the arms.

4. A current sensor comprising:
a casing including a pair of arms and a connecting portion connecting the arms;
a plurality of magneto-electric transducers accommodated in the casing, the magneto-electric transducers being arranged along a circumference of a virtual ellipse having a first axis and a second axis crossing each other at a center thereof, the first axis being a major axis of the virtual ellipse extending between the arms and coinciding with an intermediate line between the arms, and the second axis being a minor axis of the virtual ellipse, the major axis being longer than the minor axis; and
a fastening member disposed between the arms,
wherein the casing includes:
a first wire supporting portion provided on an inner wall of one of the arms; and
a second wire supporting portion provided on an inner wall of the connecting portion,

wherein the fastening member has a sloped surface inclined from one of the arms to the other arm, the sloped surface supporting a current wire between the first supporting portion and the second supporting portion,
and wherein a center of the current wire is displaced from the center of the virtual ellipse along a direction oblique to the major axis depending on an outer diameter of the current wire.

5. The current sensor according to claim 4 , wherein the first wire supporting portion, the second wire supporting portion, and the sloped surface fasten the current wire such that the center of the current wire is displaced in a first direction if the current wire has a different diameter, wherein a change in sensitivity caused by the displacement in the first direction is relatively smaller than that caused by a displacement in a direction along the first axis or the second axis of the virtual ellipse.

6. The current sensor according to claim 4 , wherein the first wire supporting portion, the second wire supporting portion, and the sloped surface are arranged such that the current wire is pressed in a direction angled at 45° from the first axis towards the one of the arms.

7. The current sensor according to claim 5 , wherein the first direction is angled at 45° from the first axis towards the one of the arms.

8. A current sensor comprising:
a casing including a pair of arms and a connecting portion connecting the arms;
a plurality of magneto-electric transducers accommodated in the casing, the magneto-electric transducers being arranged along a circumference of a virtual ellipse having a first axis and a second axis crossing each other at a center thereof, the first axis being a major axis of the virtual ellipse extending between the arms and coinciding with an intermediate line between the arms, and the second axis being a minor axis of the virtual ellipse, the major axis being longer than the minor axis; and
a fixing mechanism configured to hold a current wire between the arms such that a center of the current wire is displaced from the center of the virtual ellipse along a first direction if the current wire has a different diameter, the first direction being angled at a predetermined angle from the first axis toward one of the arms.

9. The current sensor according to claim 8 , wherein the fixing mechanism includes:
a fixing portion disposed on the casing at the first direction viewed from a center of the current wire held between the arms; and
a cord or strip-like band attached to the fixing portion, the band fastening the current wire to the fixing portion.

10. The current sensor according to claim 8 , wherein the fixing mechanism includes:
a first wire supporting portion provided on an inner wall of one of the arms;
a second wire supporting portion provided on an inner wall of the connecting portion; and
a fastening member disposed between the arms, the fastening member having a sloped surface inclined from one of the arms to the other, the sloped surface supporting the current wire between the first supporting portion and the second supporting portion.

11. The current sensor according to claim 8 , wherein a change in sensitivity caused by the displacement in the first direction is relatively smaller than that caused by a displacement of the current wire in a direction along the first axis or the second axis of the virtual ellipse.

12. The current sensor according to claim 8 , wherein the predetermined angle is about 45°.

13. The current sensor according to claim 1 , wherein the virtual ellipse is uniquely defined by the plurality of magneto-electric transducers arranged therealong.

14. The current sensor according to claim 1 , wherein a number of the plurality of magneto-electric transducers is eight.

15. The current sensor according to claim 1 , wherein the plurality of magneto-electric transducers are not arranged on the major axis of the virtual ellipse.

16. The current sensor according to claim 4 , wherein the plurality of magneto-electric transducers are not arranged on the major axis of the virtual ellipse.

17. The current sensor according to claim 8 , wherein the plurality of magneto-electric transducers are not arranged on the major axis of the virtual ellipse.

18. The current sensor according to claim 1 , wherein the fixing member is disposed in a location on a surface of the casing including an intersection point of the one of the arms and the connecting portion, the intersection point being an intersection of a first virtual line on the surface extending in a direction of the first axis along an inner wall of the one of the arms, and a second virtual line on the surface extending in a direction of the second axis and tangent to a lower surface of the connecting portion.

19. The curre

Assignees

• Alps Electric Co Ltd

Inventors

• Mitsuya Shinji

Classifications

• G01R15/207 Primary

  Constructional details independent of the type of device used · CPC title