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Publication numberUS2521536 A
Publication typeGrant
Publication dateSep 5, 1950
Filing dateJun 5, 1948
Priority dateJun 5, 1948
Publication numberUS 2521536 A, US 2521536A, US-A-2521536, US2521536 A, US2521536A
InventorsReardon Robert T
Original AssigneeGen Electric
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Electric induction device
US 2521536 A
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Description  (OCR text may contain errors)

Sept 5 1950 R. T. REARDQN ,52h53 Emc'mxc .INDUCTION DEVICE Filed zum 5, 194e Inventor-z @Obert T Reardon.,

His Attorney.

Patented Sept. v5, 1950 ELECTRIC INDUCTION DEVICE Robert T..Reardon, Fort Wayne, Ind., assignor to General Electric Company, a corporation of New York Application J une 5,

1 claim. 1

This invention relates to electric induction devices and more particularly to transformers and reactors.

It is often necessary, particularly in circuits which contain gaseous discharge lamps having negative resistance characteristics, to utilize some means of limiting the circuit current. This may be done by the addition of resistance to the circuit but the usual method, resulting in greater economy, is to use a current limiting reactor. This may be an inductive device which has high leakage reactance resulting in an increased voltage drop as the current drawn through the device increases. It is customary to incorporate, since higher-than line `voltages may be necessary for the operation of gaseous discharge lamps, this high reactance in a step-up transformer resulting in a high reactance current limiting transformer. In the conventional high reactance transformer construction the high leakage ux is achieved by providing a low reluctance leakage path utilizing magnetic shunts between the primary and secondary coils. l

In accordance with the particular-application of this invention set forth here the use of the magnetic shunts to provide a low reluctance leakage path is eliminated by winding either the primary or secondary coils of the transformer, or both, of wire which is formed of two materials; one a low resistance material such as copper and the other a magnetic material such as iron. In this manner the high reluctance of the air path which would normally be transversed by the leakage flux is decreased by the presence of the magnetic material in the winding. It should be noted that only a portion of the primary or secondary windings need be wound with this specially prepared wire.

It is an object of this invention to provide a new and simple high reactance transformer construction which eliminates the use of magnetic shunts.

It is another object of this invention to provide l a new and simple high reactance transformer construction which achieves a low reluctance leakage path by utilizing a coil winding which possesses magnetic properties'.

Still another object of this invention is to provide a new and simple high reactance transformer construction which has primary or secondary coils, or both. wound entirely or partially of wire which is formed from two materials; one presenting high electrical conductivity and the other presenting high magnetic conductivity.

A further object of this invention is to provide 1948, Serial No. 31,347

a new and simple induction apparatus which occupies less space than the usual device.

The invention will be better understood from the following description taken in connection 5 with the accompanying drawing and its scope will be pointed out in the appended claim.

In the drawing Fig. 1 is a plan view of a particular embodiment of the invention as applied to the construction of a luminous tube transformer and ballast. Fig. 2 is a cross sectional view taken through the primary coil of the transformer and ballast shown in Fig. 1.

Referring now to the drawing, there is shown in Fig. l, by way of example, a luminous tube transformer and ballast I having a primary coil 2 and secondary coils 3 and 4 prepared in accordance with this invention. The transformer coils 2, 3 and 4 are mounted on a magnetic core E which presents a low reluctance ux path and are separated from the core 5 by the insulation 6. In Fig. 2, the cross sectional view of the primary winding 2 of the transformer and ballast i shown in Fig. 1, the primary coil 2 is wound from a preferred form of wire having an outer section I formed from a magnetic material having a relatively high electrical resistivity and a center section 8 formed from a highly conductive material having a low magnetic permeability. Thus the wire may, for example, have an outer iron section l formed on a copper core 8. It should be noted that either the primary coil 2 or the secondary coils 3 and 4 or primary and secondary coils or portions thereof may be prepared from this preferred form of wire.

As can be seen in Fig. 1, the disposition of the transformer coils 2, 3 and 4 is such that the secondary coils 3 and 4 are mounted on the magnetic core' 5, one on either side of the primary coil 2. In the conventional form of luminous tube transformer and ballast, magnetic shunts are interposed between the primary coil and the secondary coil in such a manner as to present a low reluctance leakage flux path. The transformer I construction disclosed by this invention achieves a high reactance ballasting eiect by the use of a low reluctance leakage flux path andin so doing eliminates the magnetic shunts which are normally present. The shunts are, in effect, replaced by the magnetic outer surface 'l of the wire from which, in the illustrated case, the primary coil 2 is wound. A leakage path, as shown by the lines 9 in Fig. 2, is formed by the magnetic surface of the wire and, therefore, a substantial amount of iiux produced by current flow in the 55 primary 2 is not utilized in linking the primary and secondary coils 2, 3 and 4. Since the shunts are eliminated a more compact ballast and transformer I, which is important from the commercial standpoint, may be constructed.

While there has been shown and described a particular embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the invention and, therefore, it is aimed in the appended claim to cover all such changes and modiications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

In an electric transforming device atleast one primary coil member and one secondary coil member mounted on a magnetic core member and being insulated therefrom, said magnetic core member presenting a substantially closed magnetic path, at least one of said coil members having a L plurality of contiguous turns constructed of wire formed from two different materials, said wire aillxed thereto, said copper and said iron being conductively connected in parallel. said iron sheath of contiguous turns of said wire being in. contact so as to establish with said core l. relatively low reluctance substantially closed lelhle flux path of magnetic material.


REFERENCES crrlm The following references are of record in the file of this patent:

UNITED STATES PATENTS Date Number Name 1,306,815 Houchin June 17, 1919 1,406,002 Goodman Feb. 7, 1922 1,406,328 Atherton Feb. 14, 1922 1,792,756 Osnos Feb. 17, 1931 1,836,615 Owen Dec. 15, 1931 1,972,319 Rypinskl Sept. 4, 1934 2,075,906 Maude Apr. 8, 1937 2,223,737 Moses Dec. 3, 1940

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1306815 *Apr 30, 1917Jun 17, 1919 houchin and c
US1406002 *Nov 20, 1917Feb 7, 1922Goodman JosephProtective means for electrical apparatus having windings
US1406328 *Jan 29, 1917Feb 14, 1922Westinghouse Electric & Mfg CoTemperature-regulating means for filamentary electrodes
US1792756 *Oct 22, 1925Feb 17, 1931Drahtlose Telegraphie GmbhModulation system
US1836615 *Jan 31, 1929Dec 15, 1931Owen Frederick CTransformer for electric arc cutting and welding apparatus
US1972319 *May 18, 1933Sep 4, 1934Albert B RypinskiCoil for slow electromagnets and reactors
US2075906 *Apr 6, 1932Apr 6, 1937Maude Aylmer HConductor
US2223737 *Dec 22, 1938Dec 3, 1940Westinghouse Electric & Mfg CoShield for electrical apparatus
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2724091 *May 13, 1950Nov 15, 1955Klapperich Alfred JControlling the q values of coils
US2982947 *Nov 21, 1955May 2, 1961Nat Res DevMagnetic systems and devices
US4725768 *Nov 6, 1986Feb 16, 1988Toko Kabushiki KaishaSwitching regulated power supply employing an elongated metallic conductive inductor having a magnetic thin film coating
US4750077 *Jan 6, 1986Jun 7, 1988Mitsubishi Denki Kabushiki KaishaCoil device
US5430424 *Mar 14, 1994Jul 4, 1995Kabushiki Kaisha ToshibaPlanar transformer
US6189202Dec 9, 1998Feb 20, 2001Taiyo Yuden Kabushiki KaishaMethod of manufacturing chip inductors and chip inductor arrays
US6343413Aug 30, 2000Feb 5, 2002Taiyo Yuden Kabushiki KaishaMethod of manufacturing a chip inductor
US6362713 *Aug 22, 1997Mar 26, 2002Taiyo Yuden Kabushiki KaishaChip inductor, chip inductor array and method of manufacturing same
US6791444Aug 9, 2000Sep 14, 2004Taiyo Yuden Kabushiki KaishaChip inductor, chip inductor array and method of manufacturing same
U.S. Classification336/155, 336/177, 336/222, 336/199, 336/83, 336/221
International ClassificationH01F27/28
Cooperative ClassificationH01F27/2823
European ClassificationH01F27/28B