US3813770A - Method of encapsulating coils - Google Patents

Method of encapsulating coils Download PDF

Info

Publication number
US3813770A
US3813770A US00352816A US35281673A US3813770A US 3813770 A US3813770 A US 3813770A US 00352816 A US00352816 A US 00352816A US 35281673 A US35281673 A US 35281673A US 3813770 A US3813770 A US 3813770A
Authority
US
United States
Prior art keywords
coils
aluminum
refractory
coil
method defined
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
US00352816A
Inventor
E Sopcak
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.)
JETRO MATIC IND CORP
JETRO MATIC IND CORP US
Original Assignee
JETRO MATIC IND CORP
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 JETRO MATIC IND CORP filed Critical JETRO MATIC IND CORP
Priority to US00352816A priority Critical patent/US3813770A/en
Application granted granted Critical
Publication of US3813770A publication Critical patent/US3813770A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • H01F41/12—Insulating of windings
    • H01F41/127—Encapsulating or impregnating
    • 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
    • Y10T29/4902—Electromagnet, transformer or inductor
    • Y10T29/49071—Electromagnet, transformer or inductor by winding or coiling

Definitions

  • the disclosed method is particularly adapted to encapsulating electrically conductive coils in a metal body, wherein the coils may be partially dissolved or washed during casting or potting.
  • the article of manufacture is a magnetic field collecting device, particularly suitable for fuel saving devices.
  • the coils are coated-with the refractory by first coating the coils with a volatilizable organic carrier having powdered refractory-s'uspended therein and heating the coils to substantially volatilize the carrier and leaving a thin coating of the refractory.
  • the coil is then encapsulated in alumi num by pouring the molten aluminum around the coil and finally cooling the metal, forming an aluminum body.
  • the coils are formed by winding conductive wire around an aluminum arbor or the like.
  • the coils are coated with a powder refractory, such as TiO or SiO suspended in an organic carrier, such as a water soluble acrylic.
  • the coils are placed in a mold on the arbor and the molten aluminum is poured around the coils in the mold, forming the aluminum body integral with the arbor.
  • the preferred article made by the above process includes two copper coils wound in the same direction about parallel axes and an aluminum body encapsulating the coils.
  • the device is utilized to induce or collect a magnetic field in a fuel saving device and the aluminum body has been found to improve the effectiveness of the devicel BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. I is a topperspective view of the mold utilized in the method of this. invention with the coils in place;
  • FIG. 2 is a top elevation of one embodiment of an article formed by the method of this invention.
  • the method'of this invention was particularly developed to encapsulate a plurality of conductive coils, such as copper, in insulated relation in a metal body.
  • a device is utilized ina new system adapted to improvethe engine efficiency of an automotive engine or the like by impressingunidirectional magnetic field" across the engine.
  • the disclosed device is retained adjacent a source of pulsatingDC current, such as an automotive ignition coil, and a-magnetic field is thereby induced in the coils.'lt has now been discovered that encapsulating the coils in aluminum substantially improves the efficiency of the system, apparently by concentrating or collecting the magnetic field in the coils.
  • the coils are encapsulated in a conventional vertical mold 20 having an internal cavity 22 configured to form the device, as shown in FIG.
  • the coils 24 are supported in spaced relation within the mold cavity on arbors or cylindrical pins 26.
  • the arbors are preferably formed of the same material as the encapsulating material, which in the disclosed embodiment is aluminum.
  • the disclosed device includes two copper coils wound inthe same direction on parallel axes.
  • the coils 24 are left hand windings having copper connectors 28.
  • the connectors in the disclosed embodiment are conventional copper caps used to connect the coils in the engine efficiency system.
  • the coils in the preferred embodiment are coated with a thin layer of powdered refractory prior to encapsulation.
  • The'powdered refractory provides electrical insulation for the coils and prevents surface washing or dissolving of the copper coils by the molten aluminum during encapsulation.
  • the coils are preferablycoated with the refractory by first coating the coils with the refractory suspended in a volatilizable organic carrier or binder and then heating the coils to substantially volatilize the carrier, leaving a thin residue ofthe powdered refractory and sufficient binder to retain the refractory coating.
  • the coils may be dipped in a sili- I cone oil having SiO suspended therein and heated in a conventional furnace to about 500 F. The coils will then have a fine coating of SiO which provides the necessary insulation and protects the coils during encapsulation.
  • the silicone oil may be of commercial gradeand the weight percent of silicone is not considered critical.
  • Another method, which has been found particularly suitable for coating the coils of the disclosed device with a refractory utilizes a commercial acrylic paint which includes titania (TiO Titania is used in commercial paint to add opacity.
  • a suitable acrylic paint is a water soluble vinyl acrylic copolymer resin having TiO suspended therein sold by Sears, Roebuck and Company.
  • a typical formulation, by weight, for this paint is as follows:
  • Titania 25.57 Silicates l3.3'/1 Vinyl acrylic resins 14.77: Water 46.5% Total
  • the coils are dipped inthe acrylic paint,- permitted to dry and then heated in a conventional furnace at a temperature of between about 500 and 550 F. until the acrylic resin is substantially volatilized.
  • the coils then include a thin coating of titania.
  • other refractories may also be utilized, including M 0 MgO, Zr0 and mullite, which is A1 0 SiO
  • the coils 24 are supported within face 32 which is secured to a cylindrical supporting sur- 7 face in the engine efficiency system, such as an automotive ignition coil.
  • the ignition coil is a source of pulsating DC current, inducing a current 24. It has now been discovered that the aluminum body 30 substantially improves the efficiency of the system, apparently because the aluminum body collects or concentrates the electric field. In the engine efficiency system, the coils must be isolated electrically and insulated from the engine and system. The powdered refractory provides the necessary insulation and prevents surface washing of the copper during encapsulation.
  • the preferred embodiment of the device includes copper coils encapsulated in an aluminum body.
  • a suitable material for the coils is an uncoated bus bar wire, which is commercially pure copper. Copper melts at 1,98 1 F., which is above the melting temperature of aluminum.
  • a suitable material for the body is commercial 319 aluminum, which includes 4 percent by weight copper and 6 percent by weight silicon. The aluminum melts at between l,050 and l,075 F. and the normal pouring temperature of commercial 319 aluminum is l,350 F. At these temperatures, however, the molten aluminum would wash the surface of the copper wires, partially dissolving the copper and possibly breaking electrical contact. The coating of the wires with a powdered refractory then protects the coils and provides the necessary electrical insulation.
  • a method of encapsulating a copper coil in an aluminum body comprising:
  • said liquid organic carrier is a commercial acrylic paint having powdered TiO suspended therein, including dipping said coil in said acrylic paint and heating said coated coil to a temperature between about 500 and 550 F., thereby volatilizing the acrylic binder and leaving a thin coating of powdered TiO 4.
  • said organic carrier is a silicone oil having pow.- dered Si0 suspended therein, including heating said coil to a temperature above about 500? F., thereby volatilizing said oiland leaving aresidue of SiO, on said coil.
  • each of said coils with a thin layer of powdered refractory
  • said conductive coils are each coated with a refractory selected from the group consisting of SiO TiO A1 0 MgO, SrO and mullite, by coating said coils with said refractory suspended in a liquid organic carrier which is substantially volatilizable at elevated temperatures and heating said coils above the volatilization temperature of the binder, but below-the melting temperature of aluminum.
  • a refractory selected from the group consisting of SiO TiO A1 0 MgO, SrO and mullite
  • said acrylic binder is a commercial paint having powdered TiO suspended therein, including heating said coils to a temperature between about 500 and 550 F., leaving a residue of powdered TiO on said coils.
  • each of said coils with a thin layer of powdered refractory by first coating said coils with a refractory suspended in a volatilizable carrier and heating said coils to volatilize said carrier, leaving a residue coating of said refractory,

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • General Induction Heating (AREA)

Abstract

A method of encapsulating conductive coils, including coating the coil with a refractory suspended in a volatilizable organic carrier, heating the coil to volatilize the carrier and leaving a film residue of refractory, and potting the coil in aluminum or the like by pouring molten metal around the coil. The disclosed device includes two copper coils wound in the same direction about common axes and an aluminum body completely encapsulating the coils.

Description

1 METHOD OF ENCAPSULATING COILS FIELD OF THE INVENTION The disclosed method is particularly adapted to encapsulating electrically conductive coils in a metal body, wherein the coils may be partially dissolved or washed during casting or potting. The article of manufacture is a magnetic field collecting device, particularly suitable for fuel saving devices.
SUMMARY OF THE INVENTION A method of encapsulating conductive coils, such as copper, in aluminum or-the like, wherein the coils are first coated with a powdered refractory providing elec-' trical insulation forthe coils and preventing washing or dissolving of the coils during potting. The coils are coated-with the refractory by first coating the coils with a volatilizable organic carrier having powdered refractory-s'uspended therein and heating the coils to substantially volatilize the carrier and leaving a thin coating of the refractory. The coil is then encapsulated in alumi num by pouring the molten aluminum around the coil and finally cooling the metal, forming an aluminum body.
In the preferred method; of this invention, the coils are formed by winding conductive wire around an aluminum arbor or the like. The coils are coated with a powder refractory, such as TiO or SiO suspended in an organic carrier, such as a water soluble acrylic. The coils are placed in a mold on the arbor and the molten aluminum is poured around the coils in the mold, forming the aluminum body integral with the arbor.
The preferred article made by the above process includes two copper coils wound in the same direction about parallel axes and an aluminum body encapsulating the coils. The device is utilized to induce or collect a magnetic field in a fuel saving device and the aluminum body has been found to improve the effectiveness of the devicel BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a topperspective view of the mold utilized in the method of this. invention with the coils in place;
and
FIG. 2 is a top elevation of one embodiment of an article formed by the method of this invention.
DESCRIPTION OF THE INVENTION The method'of this invention was particularly developed to encapsulate a plurality of conductive coils, such as copper, in insulated relation in a metal body. Such a device is utilized ina new system adapted to improvethe engine efficiency of an automotive engine or the like by impressingunidirectional magnetic field" across the engine. The disclosed device is retained adjacent a source of pulsatingDC current, such as an automotive ignition coil, and a-magnetic field is thereby induced in the coils.'lt has now been discovered that encapsulating the coils in aluminum substantially improves the efficiency of the system, apparently by concentrating or collecting the magnetic field in the coils.
' The method 'of this invention is however not limited to this device and has other important applications.
In the disclosed method, the coils are encapsulated in a conventional vertical mold 20 having an internal cavity 22 configured to form the device, as shown in FIG.
' and magnetic field in the coils l. The coils 24 are supported in spaced relation within the mold cavity on arbors or cylindrical pins 26. The arbors are preferably formed of the same material as the encapsulating material, which in the disclosed embodiment is aluminum. In the preferred embodiment of the engine efficiency system, the disclosed device includes two copper coils wound inthe same direction on parallel axes. The coils 24 are left hand windings having copper connectors 28. The connectors in the disclosed embodiment are conventional copper caps used to connect the coils in the engine efficiency system.
The coils in the preferred embodiment are coated with a thin layer of powdered refractory prior to encapsulation. The'powdered refractory provides electrical insulation for the coils and prevents surface washing or dissolving of the copper coils by the molten aluminum during encapsulation. The coils are preferablycoated with the refractory by first coating the coils with the refractory suspended in a volatilizable organic carrier or binder and then heating the coils to substantially volatilize the carrier, leaving a thin residue ofthe powdered refractory and sufficient binder to retain the refractory coating. For example, the coils may be dipped in a sili- I cone oil having SiO suspended therein and heated in a conventional furnace to about 500 F. The coils will then have a fine coating of SiO which provides the necessary insulation and protects the coils during encapsulation. The silicone oil may be of commercial gradeand the weight percent of silicone is not considered critical.
Another method, which has been found particularly suitable for coating the coils of the disclosed device with a refractory utilizes a commercial acrylic paint which includes titania (TiO Titania is used in commercial paint to add opacity. A suitable acrylic paint is a water soluble vinyl acrylic copolymer resin having TiO suspended therein sold by Sears, Roebuck and Company. A typical formulation, by weight, for this paint is as follows:
. Titania 25.57: Silicates l3.3'/1 Vinyl acrylic resins 14.77: Water 46.5% Total The coils are dipped inthe acrylic paint,- permitted to dry and then heated in a conventional furnace at a temperature of between about 500 and 550 F. until the acrylic resin is substantially volatilized. The coils then include a thin coating of titania. It has also been found that other refractories may also be utilized, including M 0 MgO, Zr0 and mullite, which is A1 0 SiO As described above, the coils 24 are supported within face 32 which is secured to a cylindrical supporting sur- 7 face in the engine efficiency system, such as an automotive ignition coil. In this location, the ignition coil is a source of pulsating DC current, inducing a current 24. It has now been discovered that the aluminum body 30 substantially improves the efficiency of the system, apparently because the aluminum body collects or concentrates the electric field. In the engine efficiency system, the coils must be isolated electrically and insulated from the engine and system. The powdered refractory provides the necessary insulation and prevents surface washing of the copper during encapsulation.
As described above, the method of this invention is not limited to the specific materials. The preferred embodiment of the device includes copper coils encapsulated in an aluminum body. A suitable material for the coils is an uncoated bus bar wire, which is commercially pure copper. Copper melts at 1,98 1 F., which is above the melting temperature of aluminum. A suitable material for the body is commercial 319 aluminum, which includes 4 percent by weight copper and 6 percent by weight silicon. The aluminum melts at between l,050 and l,075 F. and the normal pouring temperature of commercial 319 aluminum is l,350 F. At these temperatures, however, the molten aluminum would wash the surface of the copper wires, partially dissolving the copper and possibly breaking electrical contact. The coating of the wires with a powdered refractory then protects the coils and provides the necessary electrical insulation.
I claim:
l. A method of encapsulating a copper coil in an aluminum body, comprising:
a. coating a copper coil with a refractory powder suspended in a substantially volatilizable fluid organic carrier, I
b. heating the coil to volatilize said organic carrier,
- above the volatilization temperature of said fluid organic carrier,,but below the melting temperature of said copper coil, leaving a residue of said refractory powder on said coil, i c. potting said coil coated with said powdered refractory in aluminum by pouring molten aluminum around said coil, and
d. cooling the aluminum, thereby forming an aluminum body encapsulating said coil.
2. The method defined in claim 1, including coiling a copper wire around an aluminum arbor, thereby forming said copper coil.
3. The method defined in claim 1, wherein said liquid organic carrier is a commercial acrylic paint having powdered TiO suspended therein, including dipping said coil in said acrylic paint and heating said coated coil to a temperature between about 500 and 550 F., thereby volatilizing the acrylic binder and leaving a thin coating of powdered TiO 4. The method defined in claim 1, characterized in that said organic carrier is a silicone oil having pow.- dered Si0 suspended therein, including heating said coil to a temperature above about 500? F., thereby volatilizing said oiland leaving aresidue of SiO, on said coil.
5. The method defined in claim 1, including inserting said coilcoated with said refractory in a mold having the preferred internal configuration and pouring molten aluminum into said mold, wherein said refractory prevents washing of the copper coil.
6. A method of encapsulating a plurality of conductive coils in aluminum, said coils having a melting temperature above the melting temperature of aluminum and electrically insulated from each other, comprising the steps of:
a. coiling conductive wire around two aluminum arbors thereby forming two separate conductive coils, one on each of said arbors,
b. coating each of said coils with a thin layer of powdered refractory,
c. inserting said coils, while still on said arbors, intov a mold in spaced relation,
d. pouring molten aluminum into said mold, around said coils, wherein said refractory prevents washing of the coils, and
I e. cooling said aluminum, thereby forming an aluminum article having conductive coils encapsulated therein.
7. The method defined in claim 6, wherein said conductive coils are each coated with a refractory selected from the group consisting of SiO TiO A1 0 MgO, SrO and mullite, by coating said coils with said refractory suspended in a liquid organic carrier which is substantially volatilizable at elevated temperatures and heating said coils above the volatilization temperature of the binder, but below-the melting temperature of aluminum.
8. The method defined in claim 7, wherein said organic binder is a water soluble acrylic and said coils are heated to a temperature above about QQQ F.
9. The method defined in claim 8, wherein said acrylic binder is a commercial paint having powdered TiO suspended therein, including heating said coils to a temperature between about 500 and 550 F., leaving a residue of powdered TiO on said coils.
10. The method defined in claim 7, wherein said organic carrier is a silicone oil having SiO suspended therein, including heating said coils above about 500 F ll. A method of encapsulating a plurality of conduc tive coils in a conductive metal having a melting temperature below the melting temperature of said coils and said coils electrically insulated from each other, comprising the steps of:
a. coiling conductive wire around two cylindrical arbors, thereby forming two separate conductive coils, one on each of said arbors,
b. coating each of said coils with a thin layer of powdered refractory by first coating said coils with a refractory suspended in a volatilizable carrier and heating said coils to volatilize said carrier, leaving a residue coating of said refractory,
c. inserting said coils, while still on said arbors, into a mold in spaced relation,
d. pouring said metal in a molten state into said mold, around said coils, wherein said refractory prevents washing'of said coils, and
e. coolingsaid metal, thereby forming a metal article having conductive coils encapsulated therein.
12. The method defined in claim 11, wherein said metal is aluminum and said coils are copper, including pouring said aluminum at about l350 F.

Claims (11)

  1. 2. The method defined in claim 1, including coiling a copper wire around an aluminum arbor, thereby forming said copper coil.
  2. 3. The method defined in claim 1, wherein said liquid organic carrier is a commercial acrylic paint having powdered TiO2 suspended therein, including dipping said coil in said acrylic paint and heating said coated coil to a temperature between about 500* and 550* F., thereby volatilizing the acrylic binder and leaving a thin coating of powdered TiO2.
  3. 4. The method defined in claim 1, characterized in that said organic carrier is a silicone oil having powdered SiO2 suspended therein, including heating said coil to a temperature above about 500* F., thereby volatilizing said oil and leaving a residue of SiO2 on said coil.
  4. 5. The method defined in claim 1, including inserting said coil coated with said refractory in a mold having the preferred internal configuration and pouring molten aluminum into said mold, wherein said refractory prevents washing of the copper coil.
  5. 6. A method of encapsulating a plurality of conductive coils in aluminum, said coils having a melting temperature above the melting temperature of aluminum and electrically insulated from each other, comprising the steps of: a. coiling conductive wire around two aluminum arbors thereby forming two separate conductive coils, one on each of said arbors, b. coating each of said coils with a thin layer of powdered refractory, c. inserting said coils, while still on said arbors, into a mold in spaced relation, d. pouring molten aluminum into said mold, around said coils, wherein said refractory prevents washing of the coils, and e. cooling said aluminum, thereby forming an aluminum article having conductive coils encapsulated therein.
  6. 7. The method defined in claim 6, wherein said conductive coils are each coated with a refractory selected from the group consisting of SiO2, TiO2, Al2O3, MgO, SrO2 and mullite, by coating said coils with said refractory suspended in a liquid organic carrier which is substantially volatilizable at elevated temperatures and heating said coils above the volatilization temperature of the binder, but below the melting temperature of aluminum.
  7. 8. The method defineD in claim 7, wherein said organic binder is a water soluble acrylic and said coils are heated to a temperature above about 500* F.
  8. 9. The method defined in claim 8, wherein said acrylic binder is a commercial paint having powdered TiO2 suspended therein, including heating said coils to a temperature between about 500* and 550* F., leaving a residue of powdered TiO2 on said coils.
  9. 10. The method defined in claim 7, wherein said organic carrier is a silicone oil having SiO2 suspended therein, including heating said coils above about 500* F.
  10. 11. A method of encapsulating a plurality of conductive coils in a conductive metal having a melting temperature below the melting temperature of said coils and said coils electrically insulated from each other, comprising the steps of: a. coiling conductive wire around two cylindrical arbors, thereby forming two separate conductive coils, one on each of said arbors, b. coating each of said coils with a thin layer of powdered refractory by first coating said coils with a refractory suspended in a volatilizable carrier and heating said coils to volatilize said carrier, leaving a residue coating of said refractory, c. inserting said coils, while still on said arbors, into a mold in spaced relation, d. pouring said metal in a molten state into said mold, around said coils, wherein said refractory prevents washing of said coils, and e. cooling said metal, thereby forming a metal article having conductive coils encapsulated therein.
  11. 12. The method defined in claim 11, wherein said metal is aluminum and said coils are copper, including pouring said aluminum at about 1350* F.
US00352816A 1973-04-19 1973-04-19 Method of encapsulating coils Expired - Lifetime US3813770A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US00352816A US3813770A (en) 1973-04-19 1973-04-19 Method of encapsulating coils

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00352816A US3813770A (en) 1973-04-19 1973-04-19 Method of encapsulating coils

Publications (1)

Publication Number Publication Date
US3813770A true US3813770A (en) 1974-06-04

Family

ID=23386619

Family Applications (1)

Application Number Title Priority Date Filing Date
US00352816A Expired - Lifetime US3813770A (en) 1973-04-19 1973-04-19 Method of encapsulating coils

Country Status (1)

Country Link
US (1) US3813770A (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1994534A (en) * 1932-04-23 1935-03-19 Rca Corp Inductance coil and method of manufacture thereof
US2419847A (en) * 1944-06-02 1947-04-29 Gen Electric Powdered iron magnetic core
US2552999A (en) * 1946-08-31 1951-05-15 Pye Ltd Method of making inductances

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1994534A (en) * 1932-04-23 1935-03-19 Rca Corp Inductance coil and method of manufacture thereof
US2419847A (en) * 1944-06-02 1947-04-29 Gen Electric Powdered iron magnetic core
US2552999A (en) * 1946-08-31 1951-05-15 Pye Ltd Method of making inductances

Similar Documents

Publication Publication Date Title
US2848794A (en) Method of making electrical coils for high temperature use
US2590893A (en) Insulator
JPS6367284B2 (en)
US2321439A (en) Method of making vitreous coated bodies
US3223553A (en) Electrical insulating glass composition and apparatus encapsulated therewith
US3044901A (en) Process for the production of electrical resistors and resulting article
US3813770A (en) Method of encapsulating coils
US3119897A (en) Insulated wire for high temperature use and coils made therefrom
US2204623A (en) Variable resistor
US2718049A (en) Method of manufacturing bundles of very thin magnetic wires
WO1991010239A1 (en) Method of manufacturing inorganic insulator
US2991378A (en) Composite magnetic core structure and method of making same
US2994945A (en) Process for wire-wound resistor
US3083445A (en) Method of making an electrical resistance device
US4039737A (en) Electric immersion heating apparatus and methods of constructing and utilizing same
US3273225A (en) Method of making electromagnetic structures for high-temperature service
US3795046A (en) Method of making a heat sinked resistor
US3442702A (en) High-temperature magnet wire and apparatus and enamel composition for the insulation thereof
US2865093A (en) Method of silver dip soldering
US3726005A (en) Method of manufacturing flat-wire field coils
JPS56167304A (en) Heat resistance insulating coil
US4021770A (en) Electrical resistance element
US3334322A (en) Resistance thermometer and method of making the same
US1709645A (en) Immersion heater
JPS5894925A (en) Wire electrode for electric discharge machining