US1582683A - Radiocoil and process of making same - Google Patents

Radiocoil and process of making same Download PDF

Info

Publication number
US1582683A
US1582683A US16619A US1661925A US1582683A US 1582683 A US1582683 A US 1582683A US 16619 A US16619 A US 16619A US 1661925 A US1661925 A US 1661925A US 1582683 A US1582683 A US 1582683A
Authority
US
United States
Prior art keywords
sheet
resist
coating
coil
groove
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US16619A
Inventor
Francis T Harmon
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US16619A priority Critical patent/US1582683A/en
Application granted granted Critical
Publication of US1582683A publication Critical patent/US1582683A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/02—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding
    • H05K3/06—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding the conductive material being removed chemically or electrolytically, e.g. by photo-etch process
    • H05K3/061—Etching masks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/04—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing coils
    • H01F41/041—Printed circuit coils
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/16—Printed circuits incorporating printed electric components, e.g. printed resistor, capacitor, inductor
    • H05K1/165—Printed circuits incorporating printed electric components, e.g. printed resistor, capacitor, inductor incorporating printed inductors
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
    • H05K2203/01—Tools for processing; Objects used during processing
    • H05K2203/0195—Tool for a process not provided for in H05K3/00, e.g. tool for handling objects using suction, for deforming objects, for applying local pressure
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
    • H05K2203/07—Treatments involving liquids, e.g. plating, rinsing
    • H05K2203/0756—Uses of liquids, e.g. rinsing, coating, dissolving
    • H05K2203/0769—Dissolving insulating materials, e.g. coatings, not used for developing resist after exposure
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/4902—Electromagnet, transformer or inductor
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49117—Conductor or circuit manufacturing
    • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
    • Y10T29/49155—Manufacturing circuit on or in base
    • Y10T29/49156—Manufacturing circuit on or in base with selective destruction of conductive paths
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T82/00—Turning
    • Y10T82/10—Process of turning

Definitions

  • This invention relates to radio coils and method of making the same but more particularly to coils of the pan-cake type in which the wire is wound in a flat spiral, and has for its primary object to provide an im proved coil of. this class and a simple, economical and eicient method of producingy the same.
  • Fig. 1 is a front plan view of a partially completed coil.
  • Fig. 2 is an enlarged transverse section on the line 2-2 of Fig. 1.
  • Fig. 3 is a rear plan view of the coil shown in Fig. 1 after a reinforcing spider has been attached thereto.
  • Fig. 4 is an enlarged transverse section on the line 4 4 of Fig. 3.
  • Fig. 5 is a fragmentary illustrating a step in the the coil
  • Fig. 6 is a pleted coil.
  • a spiral groove as 11 is next cut in the resist and this may be accomplished in a variety of ways but I prefer to mount the sheet in a lathe and perform the cutting by mea-ns of a tool as 12 held in the cross-slide rear plan view, manufacture of front plan view of the comof the usual saddle (not shown).
  • the groove should extend through the resist and expose the metal of the sheet.
  • the tool is preferably a heated copper stylus or soldering iron having its operating end shaped as indicated in Fig. 2. This tool bakes the edges 13 of the resist bordering the groove and firmly cements the saine to the sheet.
  • the tool is first applied to the sheet substantially at the point designated 14 (Fig.
  • a groove as 16 in the resist extending from the inner termination 14 of the groove 11 to and connecting with the next outer convolution of the spiral as at 17 may be cut by a manually operated tool or in any other convenient manner.
  • a similar groove as 18 connects the outer end of the spiral groove 11 with the next convolution.
  • a reinforcing spider as 21, of celluloid, mica, or other suitable material by means of a celluloid solution or other form of adhesive which is non-soluble in benzol.
  • This spider may be formed in any suitable manner but I prefer to provide the same with a reinforcing rib as 22.
  • the next step is the applying of a coating of resist, preferably translucent, to the exposed portions of the back of the copper sheet within the spider, as indicated by shading at 23 (Fig. 5).
  • the sheet is now etched by nitric acid or other suitable etching fluid and this removes the metal which is not protected by the resist.
  • this etching fluid has cut through the metal of the sheet the grooves appear translucent.
  • the portion 23 of the plate outside the outer convolution of the spiral groove and the central portion 24 have at this time become detached from the coil 25 formed by the unetched portions of the plate between the spiral grooves and may be lifted therefrom.
  • the coating of resist is now removed with benzol, leaving the coil mounted upon the spider 21 as indicated in Fig. 6.
  • Perforations, as 26 and 27, may be provided in the terminal tabs 19 and 20, respectively, to enable wiring to be conveniently connected thereto.
  • the method of making radio coils which consists in applying to a sheet of metal a coating of chemical resisting material, removing the coating material from portions of saidsheet, and subjecting the sheet to etching fluid to remove the exposed portions thereof.
  • radio coils which consists in applying to a sheet of metal a coating of chemical resisting material, grooving the coating to expose portions of said sheet, and subjecting the sheet to etching fluid to remove the exposed portions thereof.
  • radio coils which consists in applying to a sheet of copper a coating of resist, spirally grooving the coating on one face of said sheet to expose a spiral portion of said sheet, and subjecting the sheet to etching fluid to remove the portion thereof exposed by said grooving.
  • radio coils which consists in applying to one face of a sheet of copper a coating of resist, attaching upon the opposite face a' reinforcing member, coating said opposite face with resist, cut# ting a spiral groove through the resist on the first mentioned :tace to expose portions of the sheet, and subjectingthe sheet to etching fluid to remove the portions thereof exposed by said groove.
  • rlhe method of making radio coils which consists in applying to one tace of a sheet of copper a coating of resist, attaching upon Jthe opposite face a reinforcing member, coating said opposite face With resist, cut- Lacasse ting a groove through the resist on the first mentioned face to. expose portions of the sheet, subjecting the sheet to etchin fluid to remove the portions thereof exposed by said groove, and removing the resist from the remaining portions.
  • the method of making radio coils which consists in applying to one face of a sheet of copper a coating of resist, cutting a substantially spiral groove through the layer of resist to expose the face of the sheet therebeneath, attaching a reinforcing spider upon the opposite face of said sheet, applying a coating of resist to said opposlte face, subjecting the sheet to etching fiuid to remove the metalexposed by said grooving, and removing the resist from ,the remaining portions of the sheet.
  • radio coils which consists in applying to a sheet of metal a coatino of resist, placing the coated sheet in a latie and cutting a splral groove through the layer-of resist on one face thereof, and subjecting the sheet to etching fluid to remove the metal of the sheet directly beneath said groove.
  • radio coils which consists in etching portions of a sheet of conductingl material to form a spiral slot therein.
  • radio coils which consists in applying to one face of a sheet oi copper a coating of resist, cutting a substantially spiral groove through -the coating material with a hot tool, securing a reinforcing spider upon the opposite face of said sheet, coating said opposite face with resist, subjecting the sheet to etching fluid to remove the metal directly beneath said groove, and removing the resist from the remaining portions of the sheet with a suitable solvent.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Coils Or Transformers For Communication (AREA)

Description

April 27 1926. A 1,582,683
F. T. HARMON RADIO COIL AND PROCESS OF MAKING SAME Filed March 19, 1925 Patented Apr. 27, 1926.
UNITED STATES FRANCIS T. HARMON, 0F CHICAGO, IL LINOIS.
RADIOCOIL AND PROCESS MAKING SAME.
Application led March 19, 1925. Serial No. 16,619.
To all whom z't may concern.'
Be it known that I, FRANCIS T. HARMON, a citizen of the United States, and a resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Radiocoils and Processes of Making Same, of Which the following is a specification.
This invention relates to radio coils and method of making the same but more particularly to coils of the pan-cake type in which the wire is wound in a flat spiral, and has for its primary object to provide an im proved coil of. this class and a simple, economical and eicient method of producingy the same.
Further important objects of this invention are to provide a coil having low loss and capacity and high inductance. The many other objects and advantages of my invention will be better understood by reference to the following specification when cons idered in connection with the accompanying drawing illustrating a selected embodiment thereof, in which o Fig. 1 is a front plan view of a partially completed coil.
Fig. 2 is an enlarged transverse section on the line 2-2 of Fig. 1.
Fig. 3 is a rear plan view of the coil shown in Fig. 1 after a reinforcing spider has been attached thereto.
Fig. 4 is an enlarged transverse section on the line 4 4 of Fig. 3.
Fig. 5 is a fragmentary illustrating a step in the the coil, and
Fig. 6 is a pleted coil.
The construction and characteristics of my improved radio coil will be best understood by considering the method of making the same, and reference may be had to the drawing in which the vario us steps are illustrated. I use a sheet as 9 of copper of the required gauge, generally from .001 to .02 inches, but preferably about .004 inches, and upon'one face of this sheet I apply a coating of resist as 10, or any suitable composition such as asplialtum which will resist the action of etching fluids.
A spiral groove as 11 is next cut in the resist and this may be accomplished in a variety of ways but I prefer to mount the sheet in a lathe and perform the cutting by mea-ns of a tool as 12 held in the cross-slide rear plan view, manufacture of front plan view of the comof the usual saddle (not shown). The groove should extend through the resist and expose the metal of the sheet. The tool is preferably a heated copper stylus or soldering iron having its operating end shaped as indicated in Fig. 2. This tool bakes the edges 13 of the resist bordering the groove and firmly cements the saine to the sheet. In the form of the coil illustrated in Fig. 1 the tool is first applied to the sheet substantially at the point designated 14 (Fig. l), and the grooving of the resist by this tool continues until the tool has advanced suiiiciently to provide the desired number of convolutions as to 15. A groove as 16, in the resist extending from the inner termination 14 of the groove 11 to and connecting with the next outer convolution of the spiral as at 17 may be cut by a manually operated tool or in any other convenient manner. A similar groove as 18 connects the outer end of the spiral groove 11 with the next convolution. These form terminal tabs as 19 and 20 on the finished coil, as will be presently described.
I next cement upon the back of the sheet 9 a reinforcing spider, as 21, of celluloid, mica, or other suitable material by means of a celluloid solution or other form of adhesive which is non-soluble in benzol. This spider may be formed in any suitable manner but I prefer to provide the same with a reinforcing rib as 22.
The next step is the applying of a coating of resist, preferably translucent, to the exposed portions of the back of the copper sheet within the spider, as indicated by shading at 23 (Fig. 5). The sheet is now etched by nitric acid or other suitable etching fluid and this removes the metal which is not protected by the resist. As soon as this etching fluid has cut through the metal of the sheet the grooves appear translucent. The portion 23 of the plate outside the outer convolution of the spiral groove and the central portion 24 have at this time become detached from the coil 25 formed by the unetched portions of the plate between the spiral grooves and may be lifted therefrom. The coating of resist is now removed with benzol, leaving the coil mounted upon the spider 21 as indicated in Fig. 6. Perforations, as 26 and 27, may be provided in the terminal tabs 19 and 20, respectively, to enable wiring to be conveniently connected thereto.
It will be evident from the foregoing description that my coil is simple and economical to produce. The finished coil is neat in appearance and the convolutions are uniformly spaced. This coil is in the form of a metal tape or fiat strip Wound in a fiat spiral with the convolutions arranged edge to edge and maintained in spaced relation by the reinforcing spider.
I claim as my lnvention:
1. The method of making radio coils which consists in applying to a sheet of metal a coating of chemical resisting material, removing the coating material from portions of saidsheet, and subjecting the sheet to etching fluid to remove the exposed portions thereof.
2. The method of making radio coils which consists in applying to a sheet of metal a coating of chemical resisting material, grooving the coating to expose portions of said sheet, and subjecting the sheet to etching fluid to remove the exposed portions thereof.
3. The method of making radio coils which consists in applying to a sheet of copper a coating of resist, spirally grooving the coating on one face of said sheet to expose a spiral portion of said sheet, and subjecting the sheet to etching fluid to remove the portion thereof exposed by said grooving.
1i. The method of making radio coils which consists in applying to one face of a sheet of copper a coating of resist, attaching upon the opposite face a' reinforcing member, coating said opposite face with resist, cut# ting a spiral groove through the resist on the first mentioned :tace to expose portions of the sheet, and subjectingthe sheet to etching fluid to remove the portions thereof exposed by said groove. I
5. rlhe method of making radio coils which consists in applying to one tace of a sheet of copper a coating of resist, attaching upon Jthe opposite face a reinforcing member, coating said opposite face With resist, cut- Lacasse ting a groove through the resist on the first mentioned face to. expose portions of the sheet, subjecting the sheet to etchin fluid to remove the portions thereof exposed by said groove, and removing the resist from the remaining portions.
6. The method of making radio coils which consists in applying to one face of a sheet of copper a coating of resist, cutting a substantially spiral groove through the layer of resist to expose the face of the sheet therebeneath, attaching a reinforcing spider upon the opposite face of said sheet, applying a coating of resist to said opposlte face, subjecting the sheet to etching fiuid to remove the metalexposed by said grooving, and removing the resist from ,the remaining portions of the sheet.
7 vThe method of making radio coils which consists in applying to a sheet of metal a coatino of resist, placing the coated sheet in a latie and cutting a splral groove through the layer-of resist on one face thereof, and subjecting the sheet to etching fluid to remove the metal of the sheet directly beneath said groove.
8. The method of making radio coils which consists in etching portions of a sheet of conductingl material to form a spiral slot therein.
9. The method of making radio coils Which consists in applying to one face of a sheet oi copper a coating of resist, cutting a substantially spiral groove through -the coating material with a hot tool, securing a reinforcing spider upon the opposite face of said sheet, coating said opposite face with resist, subjecting the sheet to etching fluid to remove the metal directly beneath said groove, and removing the resist from the remaining portions of the sheet with a suitable solvent.
FRNClS T. HARMON.
US16619A 1925-03-19 1925-03-19 Radiocoil and process of making same Expired - Lifetime US1582683A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US16619A US1582683A (en) 1925-03-19 1925-03-19 Radiocoil and process of making same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US16619A US1582683A (en) 1925-03-19 1925-03-19 Radiocoil and process of making same

Publications (1)

Publication Number Publication Date
US1582683A true US1582683A (en) 1926-04-27

Family

ID=21778081

Family Applications (1)

Application Number Title Priority Date Filing Date
US16619A Expired - Lifetime US1582683A (en) 1925-03-19 1925-03-19 Radiocoil and process of making same

Country Status (1)

Country Link
US (1) US1582683A (en)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2474988A (en) * 1943-08-30 1949-07-05 Sargrove John Adolph Method of manufacturing electrical network circuits
US2506604A (en) * 1947-02-01 1950-05-09 Robert P Lokker Method of making electronic coils
US2535674A (en) * 1946-05-11 1950-12-26 Albert W Franklin Die for cutting electrical units
US2587568A (en) * 1943-02-02 1952-02-26 Hermoplast Ltd Manufacture of electric circuit components
US2632693A (en) * 1950-10-30 1953-03-24 Honeywell Regulator Co Method of producing an electrical wiring grid
US2706366A (en) * 1950-11-25 1955-04-19 Bell Telephone Labor Inc Method of constructing a helix assembly
US2723933A (en) * 1950-01-31 1955-11-15 Hans D Isenberg Method of making preformed insulation for high voltage transformer
US2882458A (en) * 1953-11-13 1959-04-14 Sundstrand Machine Tool Co Multipole chuck
US2948954A (en) * 1956-03-08 1960-08-16 Alexander P Ramsa Small sized helixes and method of their fabrication
US3000079A (en) * 1955-05-05 1961-09-19 Aladdin Ind Inc Tuner and method for making same
US3123787A (en) * 1964-03-03 Toroidal transformer having a high turns ratio
US3508457A (en) * 1967-09-27 1970-04-28 Us Navy Process for constructing thin film inductors
US5048382A (en) * 1989-08-23 1991-09-17 Mar Don Corporation Method for making elastomeric sealing device
US6143157A (en) * 1995-11-27 2000-11-07 Vlt Corporation Plating permeable cores
WO2008073524A2 (en) * 2006-07-10 2008-06-19 Mar Don Corporation Improved method for making an elastomeric sealing device

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3123787A (en) * 1964-03-03 Toroidal transformer having a high turns ratio
US2587568A (en) * 1943-02-02 1952-02-26 Hermoplast Ltd Manufacture of electric circuit components
US2474988A (en) * 1943-08-30 1949-07-05 Sargrove John Adolph Method of manufacturing electrical network circuits
US2535674A (en) * 1946-05-11 1950-12-26 Albert W Franklin Die for cutting electrical units
US2506604A (en) * 1947-02-01 1950-05-09 Robert P Lokker Method of making electronic coils
US2723933A (en) * 1950-01-31 1955-11-15 Hans D Isenberg Method of making preformed insulation for high voltage transformer
US2632693A (en) * 1950-10-30 1953-03-24 Honeywell Regulator Co Method of producing an electrical wiring grid
US2706366A (en) * 1950-11-25 1955-04-19 Bell Telephone Labor Inc Method of constructing a helix assembly
US2882458A (en) * 1953-11-13 1959-04-14 Sundstrand Machine Tool Co Multipole chuck
US3000079A (en) * 1955-05-05 1961-09-19 Aladdin Ind Inc Tuner and method for making same
US2948954A (en) * 1956-03-08 1960-08-16 Alexander P Ramsa Small sized helixes and method of their fabrication
US3508457A (en) * 1967-09-27 1970-04-28 Us Navy Process for constructing thin film inductors
US5048382A (en) * 1989-08-23 1991-09-17 Mar Don Corporation Method for making elastomeric sealing device
US6143157A (en) * 1995-11-27 2000-11-07 Vlt Corporation Plating permeable cores
US6165340A (en) * 1995-11-27 2000-12-26 Vlt Corporation Plating permeable cores
WO2008073524A2 (en) * 2006-07-10 2008-06-19 Mar Don Corporation Improved method for making an elastomeric sealing device
WO2008073524A3 (en) * 2006-07-10 2008-12-18 Mar Don Corp Improved method for making an elastomeric sealing device
US20090158911A1 (en) * 2006-07-10 2009-06-25 Mar Don Corporation Method for making an elastomeric sealing device
US8122795B2 (en) * 2006-07-10 2012-02-28 Mar Don Corporation Method for making an elastomeric sealing device

Similar Documents

Publication Publication Date Title
US1582683A (en) Radiocoil and process of making same
US1994767A (en) Method of making inductances
US1877254A (en) Sheet material
US3415708A (en) Table top
US2081051A (en) Electric cut-out
JPS6248364B2 (en)
CA1111145A (en) Method of making printed circuit
DE1665750B2 (en) MAGNETIC FIELD-DEPENDENT RESISTANCE WITH STRIP-SHAPED METAL GRID TO SHORT-CIRCUIT THE REAL VOLTAGE
CN208126949U (en) A kind of silicon steel core
GB1025403A (en) Rectangular waveguide and method of manufacturing it
JPS62247514A (en) Manufacture of coil
JP2587597B2 (en) Manufacturing method of printed wiring board
US2180129A (en) Manufacture of electric fuseheads such as are used, for example, in blasting detonators
DE578545C (en) Process for the production of electrical wound capacitors with paper dielectric, in which conductive and non-conductive strips are wound onto a core that remains in the winding
AT160380B (en) Process for the production of smooth, thin-walled pipe elbows with only one seam from a piece of sheet metal.
JPH0553048B2 (en)
JPS61193417A (en) Manufacture of high frequency coil
JPS59210626A (en) High-frequency core
JPH0134413Y2 (en)
JPS5927511A (en) Fixing method of wound iron core
DE2924475A1 (en) Metallising of semiconductor crystals - where semiconductor is covered with metal and then with metal oxide which aids the adhesion of photolacquer masks
JPS5527675A (en) Multiple coiling method
DE2214384C3 (en) Method for producing a thermocompression contact
DE2010701C3 (en) Process for manufacturing electrical components
DE807971C (en) Electric discharge tubes with one or more secondary emission electrodes