Transducer for current measurements

• US 4,794,326 A
• Filed: 02/23/1984
• Issued: 12/27/1988
• Est. Priority Date: 03/02/1983
• Status: Expired due to Fees

• Current Assignee: LGZ Landis & Gyr Zug AG (Landis+Gyr Group AG)
• Original Assignee: GYR ZUG AG, Lgz Landis
• Inventors: Friedl, Richard
• Primary Examiner(s): Karlsen, Ernest F.
• Application Number:
  US06/582,968
• Time in Patent Office: 1,769 Days
• Field of Search: 324/127, 324/117 H, 324/126, 324/117 R, 338/49
• US Class Current: 324/117.00R
• CPC Class Codes: G01R 15/185 with compensation or feedback windings or interacting coils, e.g. 0-flux sensors using galvano-magnetic field sensors G01R15/20; conversion of DC into AC using transductors G01R19/20
• CPC Class Codes: H01F 38/30 Constructions

Abstract

A transducer for current measurements includes a flat conductor with at least two main current branches for the current to be measured and at least a cross-branch current bridge connecting two locations of differing potential of the two main current branches. A magnetic core is laid around one of the branch current paths. The flat conductor is formed such that it is provided in its cross-direction with a bending edge for redirecting current and each main current branch or part thereof at least approximately coincides with and is of an opposite current direction to a main current branch or part thereof of the other leg.

Claims

1. A transducer for measuring a current, comprising,

a magnetic core,

a U-shaped electrical conductor comprising two legs connected along one end, said U-shaped electrical conductor having a longitudinal axis generally perpendicular to said one end and located in a central portion of said U-shaped electrical conductor, said two legs being in a generally confronting relationship to each other and in close thermal contact with one another, but spaced apart from each other by a thin insulation layer, each of said legs having an opening defined therein for receiving said magnetic core,

said magnetic core being positioned to engage each opening in each leg;

and

each of said legs including a connecting terminal, said connecting terminals operable for providing a plurality of currents in said legs when energized by being connected to an electrical source,

said currents including two main currents along each of said two legs generally parallel to said longitudinal axis, said main currents in each of said legs being on opposite sides of said longitudinal axis, the direction of flow of said main currents in one leg being opposite to the direction of flow of said main currents in the other leg,

said U-shaped electrical conductor including physical differences with respect to said longitudinal axis so as to produce a cross-current flowing between said main currents when said U-shaped electrical conductor is energized, said cross-current being located near said one end,

whereby, an electrical source can be connected to said connecting terminals to produce currents in said legs thereby generating a magnetic flux from said cross-current which is coupled to said magnetic core.

2. The transducer of claim 1 wherein said physical differences include at least one additional opening defined in at least one of said legs, said additional opening producing a difference in electrical potential between said main currents in the corresponding leg.

3. The transducer of claim 1 wherein said two legs are asymmetrical with respect to each other.

4. The transducer of claim 1 wherein each of said legs comprises a cast part.

5. The transducer of claim 1 wherein each of said legs comprises a pressed part.

6. The transducer of claim 1, wherein said connecting terminals are separated from each other by a slot which is less than approximately a quarter of the width of said connecting terminals.

7. A transducer for measuring a current, comprising,

a magnetic core having two arms,

a U-shaped electrical conductor comprising first and second legs interconnected along one end, said U-shaped electrical conductor having a longitudinal axis generally perpendicular to said one end and located in a central portion of said U-shaped electrical conductor, said first and second legs being in a generally confronting relationship to each other and in close thermal contact with one another, but spaced apart from each other by a thin insulation layer,

said first leg including two openings defined successively along said longitudinal axis, each of said openings receiving one arm of said magnetic core,

said second leg including one opening and receiving both arms of said magnetic core,

said magnetic core being positioned to engage each opening in each leg;

and

each of said first and said second legs including a connecting terminal, said connecting terminals operable for providing a plurality of currents in said legs when energized by being connected to an electrical source,

said currents including two main currents along each of said first and said second legs generally parallel to said longitudinal axis, said main currents being on opposite sides of said longitudinal axis, the first direction of flow of said main currents in said first leg being opposite to the direction of flow of said main currents in said second leg,

said U-shaped electrical conductor including physical differences with respect to said longitudinal axis so as to produce a cross-current flowing between said main currents when said U-shaped electrical conductor is energized, said cross-current being located near said one end,

whereby, an electrical source can be connected to said connecting terminals to produce currents in said legs thereby generating a magnetic flux from said cross-current which is coupled to said magnetic core.

8. The transducer of claim 7 wherein one of said legs of the conductor includes a conductor branch interrupted by an air slot, said conductor branch coinciding with the region of flow of the cross-current.

9. The transducer of claim 7 wherein said two legs of said conductor are formed substantially alike.

10. The transducer of claim 7 wherein the conductor comprises a cast part.

11. The transducer of claim 7 wherein the conductor comprises a pressed part.

12. The transducer of claim 7, wherein said connecting terminals being separated from each other by a slot which is less than approximately a quarter of the width of said connecting terminals.

13. A transducer for measuring a current, comprising,

a magnetic core having two arms,

a U-shaped electrical conductor comprising first and second legs interconnected along one end, said U-shaped electrical conductor having a longitudinal axis generally perpendicular to said one end and located in a central portion of said U-shaped electrical conductor, said first and second legs being in a generally confronting relationship to each other and in close thermal contact with one another, but separated from each other by a thin insulation layer,

said magnetic core being positioned to engage each opening in each leg;

and

said first and second legs each including two openings disposed successively along said longitudinal axis, each of said openings receiving an arm of said magnetic core, and

each of said first and said second legs including a connecting terminal, said connecting terminals operable for producing a plurality of currents in said first and second legs when energized by being connected to an electrical source,

said currents including two main currents along said first and second legs generally parallel to said longitudinal axis, said main currents on said first leg being opposite to the direction of flow of said main currents in said second leg,

said U-shaped electrical conductor including physical differences with respect to said longitudinal axis so as to produce a cross-current flowing between said main currents when said U-shaped electrical conductor is energized, said cross-current being located near said one end,

whereby, an electrical source can be connected to said connecting terminals to produce currents in said legs thereby generating a magnetic flux from said cross-current which is coupled to said magnetic core.

14. The transducer of claim 13 wherein one of said legs includes a conductor branch interrupted by an air slot, said conductor branch coinciding with the region of flow of one of the cross-currents.

15. The transducer of claim 13 further comprising a hole disposed in at least one of said legs, said hole causing a difference in potential between said main currents in the other leg.

16. The transducer of claim 13 wherein said two legs are formed substantially alike.

17. The transducer of claim 13 wherein said conductor comprises a cast part.

18. The transducer of claim 13 wherein said conductor comprises a pressed part.

19. The transducer of claim 13 further comprising terminals of said transducer for providing a connection to the voltage source, said terminals being separated by a slot which is less than approximately a quarter of the width of the terminals.