LEADLESS MICROMINIATURE INDUCTANCE ELEMENT WITH A CLOSED MAGNETIC CIRCUIT

• US 3,691,497 A
• Filed: 10/15/1970
• Issued: 09/12/1972
• Est. Priority Date: 10/15/1970
• Status: Expired due to Term

• Current Assignee: John P. Bailey, William L. Muckelroy
• Original Assignee: John P. Bailey, William L. Muckelroy
• Inventors: Muckelroy, William L., Bailey, John P.
• Primary Examiner(s): Kozma, Thomas J.
• Application Number:
  US05/080,851
• Time in Patent Office: 698 Days
• Field of Search: 336/192,200,221,212 317/11CC
• US Class Current: 336/192
• CPC Class Codes: H01F 17/04 with magnetic core

Abstract

A Microminiature leadless inductance element having a closed magnetic loop. The inductance element comprises a conventional Ushaped ferromagnetic core having a wire winding around its center. Grooves are provided at the underside of the feet of the U-shaped core so as to receive the terminal portions of the wire winding. The grooves are coated with an electrical conductor and a similar electrically conductive coating is provided on the substrate such that an electrical connection is made without the use of soldering wires. A closed magnetic loop is achieved by applying a ferromagnetic coating along a portion of the substrate surface such that when the U-shaped core is placed on the substrate, all the flux lines generated within the core are conducted through the ferromagnetic coating on the substrate. This eliminates stray flux lines and materially enhances the Q of the system.

Claims

1. A circuit element with a closed magnetic loop comprising a core having at least first and second feet, a wire winding surrounding a portion of said core, a substrate for supporting said core, a coating located along a portion of said substrate for conducting a magnetic field developed in said core, an electrically conductive coating located along a portion of the underside of each of said feet, and an electrically conductive coating on the surface of said substrate in alignment with the coating of said feet.

2. The device of claim 1 further comprising a groove located along a portion of the underside of each of said feet for receiving the two terminal portions of said wire winding.

3. The device of claim 2 wherein said electrically conductive coating at said feet extend into said groove.

4. A circuit element with a closed magnetic loop comprising;

a. a solitary and non-planar core having at least first and second Supporting feet;

b. a conductive winding surrounding a portion of said core;

c. A substrate for supporting said core; and

d. a magnetically permeable coating located along a portion of said substrate and directly beneath the underside of said supporting feet for conducting a magnetic field developed in said core.

5. A circuit element with a closed magnetic loop comprising a solitary and non-planar core having at least first and second supporting feet, a conductive winding surrounding a portion of said core, a substrate for supporting said core, a magnetically permeable coating located along a portion of said substrate for conducting a magnetic field developed in said core, said coating having sufficient surface area to receive the entire magnetic field within said core, a first electrically conductive coating located along a portion of the underside of each of said feet, and a second electrically conductive coating located on the surface of said substrate in alignment with said first electrically conductive coating.

6. The device of claim 5 further comprising a groove located along a portion of the underside of each of said feet for receiving the two terminal portions of said conductive winding.

7. The device of claim 6 wherein said electrically conductive coating at said feet extend into said groove.

8. A circuit element with a closed magnetic loop comprising a solitary and non-planar core having at least first and second supporting feet, a conductive winding surrounding a portion of said core, a substrate for supporting said core, a magnetically permeable coating located along a portion of said substrate for conducting a magnetic field developed in said core, said coating having sufficient surface area to receive the entire magnetic field within said core, a first electrically conductive coating located along a portion of the underside of each of said feet, a second electrically conductive coating on the surface of said substrate in alignment with said first electrically conductive coating, a groove located along a portion of the underside of each of said feet for receiving the two terminal portions of said conductive winding, wherein said first electrically conductive coating extends into said groove, and wherein said winding is attached to said core.

9. The device of claim 8 wherein said core further comprises at least two opposite magnetic poles formed into supporting feet each juxtaposed to a portion of said magnetically permeable coating.

10. The device of claim 8 wherein said core comprises an H-shaped magnetically permeable material.

11. The device of claim 8 wherein said core comprises a U-shaped magnetically permeable material.

12. The device of claim 4 further comprising an electrically conductive coating located along a portion of the underside of each of said feet and an electrically conductive coating on the surface of said substrate in alignment with the coating of said feet.

13. The device of claim 12 further comprising a groove located along a portion of the underside of each of said feet for receiving the two terminal portions of said conductive winding.

14. The device of claim 13 wherein said electrically conductive coating at said feet extend into said groove.

15. The device of claim 13 wherein said winding is attached to said core.

16. The device of claim 15 wherein said core further comprises at least two opposite magnetic poles formed into supporting feet each one opposed to a portion of said magnetically permeable coating.

17. The device of claim 16 wherein said core comprises an H-shaped magnetically permeable material.

18. The device of claim 16 wherein said core comprises a U-shaped magnetically permeable material.