Automated adjustment of air-core coil inductance

• US 4,980,663 A
• Filed: 12/28/1989
• Issued: 12/25/1990
• Est. Priority Date: 12/28/1989
• Status: Expired due to Fees

• Current Assignee: Ford Motor Company
• Original Assignee: Ford Motor Company
• Inventors: Moyer, Charles R.
• Primary Examiner(s): GENSLER, PAUL L
• Application Number:
  US07/458,035
• Time in Patent Office: 362 Days
• Field of Search: 334/8-10, 334/27, 334/71, 334/74-76, 336/10, 336/12, 336/20, 336/225, 324/655, 324/656, 29/593, 29/602.1, 29/705, 29/745
• US Class Current: 334/8
• CPC Class Codes: H01F 21/04 by relative movement of turns or parts of windings
• CPC Class Codes: H03J 1/06 Driving or adjusting arrangements; combined with other driving or adjusting arrangements, e.g. of gain control
• CPC Class Codes: H05K 1/18 Printed circuits structurally associated with non-printed electric components H05K1/0201, H05K1/023, H05K1/0243, and H05K1/16 take precedence
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/53022 with means to test work or product
• CPC Class Codes: Y10T 29/532 Conductor

Abstract

The inductance value of air-core coils are adjusted using automated methods and inexpensive, noncomplicated apparatus. Adjusting tools are provided which displace coil turns in a linear motion with respect to the coil centerline. Specifically, the coil turns can be displaced by sliding perpendicularly to the coil centerline or by rotating a group of coils in order to modify the coil inductance. The adjusting tools used and the method of coil-turn displacement allow the automated method to reincrease the inductance of a coil in the event that displacement causes an over-decrease of inductance.

Claims

1. A method of adjusting the inductance of an air-core coil comprising the steps of:

securing in a fixed location a helically wound air-core coil having a plurality of turns and a longitudinal centerline passing through the interior of each of said turns;

providing a multi-pronged tool;

locating at least two prongs of said multi-pronged tool on opposite sides of said coil; and

rotating said tool to contact at least one of said turns to displace at least one but less than all of said turns in a linear motion with respect to said centerline in order to modify the inductance of said coil.

2. A method of adjusting the inductance of an air-core coil comprising the steps of:

securing in a fixed location a helically wound air-core coil having a plurality of turns and a longitudinal centerline passing through the interior of each of said turns; and

displacing at least one but less than all of said turns in a linear motion with respect to said centerline in order to modify the inductance of said coil, wherein said linear motion comprises sliding individual turns in a direction substantially perpendicular to said centerline, and wherein at least one turn is displaced in a first direction and at least one other turn is displaced in a direction opposite said first direction.

3. A method of adjusting the inductance of an air-core coil comprising the steps of:

securing in a fixed location a helically wound air-core coil having a plurality of turns and a longitudinal centerline passing through the interior of each of said turns;

locating at least two prongs of a multi-pronged tool on one side of said coil and another prong of said tool on the opposite side of said coil; and

advancing said tool perpendicularly to said centerline in order to contact a plurality of said turns to displace at least one but less than all of said turns in a linear motion with respect to said centerline in order to modify the inductance of said coil, wherein said linear motion comprises sliding individual turns in a direction substantially perpendicular to said centerline, and wherein at least one turn is displaced in a first direction and at least one other turn not adjacent to said one turn is displaced in said first direction.

4. A method of adjusting the inductance of an air-core coil comprising the steps of:

securing the ends of a helically wound air-core coil in a relatively fixed position, said coil having a plurality of turns and a longitudinal centerline passing through the interior of each of said turns;

energizing said coil with an excitation current;

measuring an output parameter of said coil;

comparing said measured output parameter with a predetermined criteria corresponding to a desired tuning of said coil;

contacting said coil with a tool adapted to modify the shape of said coil; and

controlling said tool in response to said comparison to displace at least one but less than all of said turns in a linear motion with respect to said centerline until said measured output parameter satisfies said predetermined criteria.

5. The method of claim 4 wherein said predetermined criteria is to maximize said measured output parameter.

6. The method of claim 4 wherein said predetermined criteria is a comparison of said measured output parameter with a predetermined output parameter.

7. An air-core coil having a plurality of turns wound around a straight centerline, said coil comprising:

a first group of turns within said plurality of turns, each turn of said first group having said center line substantially at its center;

a second group of turns within said plurality of turns, each turn of said second group being displaced relative to said centerline in a first direction perpendicular to said centerline; and

a third group of turns within said plurality of turns, each turn of said third group being displaced relative to said centerline.

8. The coil of claim 7 wherein said third group of turns is displaced relative to said centerline in a second direction opposite to said first direction.

9. The coil of claim 7 wherein said second and third groups of turns are displaced from said centerline in substantially the same direction and wherein said second and third groups of turns are separated by turns from said first group of turns.

10. An automated coil adjustment system comprising:

test and control means adapted to be connected to a circuit containing an air-core coil to be adjusted for determining a coil modification needed to achieve a desired operation in said circuit;

adjusting tool means for contacting said air-core coil to be adjusted and for displacing at least one but less than all of the turns of said coil in a linear motion with respect to the centerline of said coil in order to modify the inductance of said coil; and

servomechanism means coupled to said test and control means and to said adjusting tool means for moving said adjustment tool means according to said coil modification determined by said test and control means.