US767497A - Mutiple secondary transformer. - Google Patents

Description

No. 76'7,497 PATENTED AUG. 16, 1904 LS. PEOK & 0. LE G. PORTESOUE.

MULTIPLE SECONDARY TRANSFORMER.

APPLICATION FILED AUG. 8, 1903. I no MODEL. 1 '2 SHEETS-SHEET 1.

6 WITNESSES: 46% wif'im Cid m No 767,497. Y PATENTED AUG. 16, 1904. J. s. P501: & 0. LB G. FORTESGUE.

MULTIPLE SECONDARY TRANSFORMER.

APPLICATION IILED'AUG. a, 1903.

Fig 5 2 SHEETS-SHEET 2.

WITNESSES:

@m I kg, f Q2 ATTOIIPNEY Patented August 16, 1904.

UNITED STATES PATENT OEEIcE.

JOHN S. PEOK, OF PITTSBURG, AND CHARLES LE G. FORTESCUE, OF VVIL- KINSBURG,

PENNSYLVANIA, ASSIGNORS TO WVESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

MULTIPLE SECONDARY TRANSFORMER.

SPECIFICATION forming part of Letters Patent No. 767,497, ated A g 16, 1904.

Application filed August 8, 1903.

T aZZ whom it may concern.-

vBe it known that we, JOHN S. PEOK, a citi Zen of the United States, residing at Pittsburg, and CHARLES LE G. FORTESCUE, a subject of the King of Great Britain, residing at VVilkinsburg, in the county of Allegheny, State of Pennsylvania, have invented a new and useful Improvement in Multiple Secondary Transformers, of which the following is [0 a specification.

Our invention relates to apparatus for transforming alternating electric currents, and particularly to apparatus of this character which have multiple secondary windings.

The object of our invention is to provide a transformer for supplying a plurality of independent sets of translating devices in such manner that variations in load upon one secondary circuit shall have substantially no effect upon the voltage of the other secondary circuit or circuits or in such manner that variations in load upon one of the secondary circuits have relatively small effect upon the voltage of the other secondary circuit or circuits.

It is frequently found desirable to supply both motors and lamps from a single transformer; but on account of the inductive character of the motor-load variations in this load are likely to be productive of serious varia- 3 tions of the voltage of the lamp-circuit. It

has therefore generally been found impracticable to operate both lamps and motors from the same transformer, since good regulation is necessary for satisfactory operation of electric lamps.

'Our present invention avoids the difficulty above stated and is illustrated in the accompanying drawings, in which- Figure 1 is a diagrammatic view of appara- 4 tus embodying and illustrating our invention in its simplest form. Figs. 2 and 3 are diagrams similar to Fig. 1, but illustrating modifications of the transformer structure. Fig. 4 is a sectional view of a transformer and illustrating one arrangement of the coils with reference to each other and to the core and showing the circuit connectionsto the generator and to translating devices diagrammat- Serial No. 168,751. (No model.)

ically. Fig. 5 is a view similar to Fig. 1, but showing a difierent arrangement of coils. Fig. 6 is a view similar to Fig. 4, but illustrating a core-type transformer. Figs. 7, 8, 9, and 10 are diagrams similar to Figs. 1, 2, and 3, but illustrating further modifications of the transformer-windings.

Our invention as here illustrated consists, generally speaking, in providing a transformer with independent secondary windings for severally supplying independent loads which may or may not differ in character and in so placing the two windings with reference to the primary winding that the leakage magnetic field produced by a load upon one circuit will have either no substantial effect upon the voltage of the other circuit or one that is productive of a minimum degree of disturbance.

As illustrated in Fig. 1, the primary winding 1 of the transformer is supplied with current from a generator 2 and in turn serves to generate currents by induction in the two secondary windings 3 and 1, which are symmetrically located at the two sides of the primary winding, the winding 3 being shown as supplying lamps 5 and the winding 4 as supplying motors 6.

In Fig. 2 the transformer is shown as provided with two primary coils 7 and 8, connected in series and supplied with current by the generator 2. The secondary winding 3, supplying the lamps 5, is here shown as consisting of a single coil located midway between the two primary coils, while the secondary winding supplying the motor or motors 6 is Shown as comprising two coils 9 and 10, respectively located at the sides of the primary coils 7 and 8.

In Fig. 8 the primary winding supplied by the generator 2 comprises four equally-spaced coils 11, 12, 13, and 14. The secondary circuit supplying the lamps 5 comprises two coils 15 and 16, located between primary coils 11 and 12, and two coils 17 and 18, located between primary coils 13 and 14, all connected in series. The secondary winding supplying the motor or motors 6 also comprises two coils 19 and 20, located between primary coils 12 and 13, andtwo coils 21 and 22, located, respectively, beside the primary coils 11 and 14. i

It is found with the arrangement of windings shown in each of the figures above described that the leakage magnetic field produced by a load upon one circuit, while it lowers the voltage on its own circuit, has a tendency to slightly raise the voltage on the other circuit, and this tendency to raise the voltage is very nearly offset by the tendency to a drop in voltage due to the ohmic resistance of the primary winding, so that changes in'load on one circuit produce substantially no effect on the voltage of the other circuit.

While one of the secondary circuits in the arrangements shown is designated as supplying lamps and the other as supplying motors, it is obvious that either circuit maybe used for the lamps and the other for the motors, since the windings are symmetrically located with reference to the primary coils.

In Figs. 1, 2, and 3 the coils are all shown as arranged parallel to each other and adapted for embodiment in transformers of the shell type of construction. Another arrangement of coils which is satisfactorily operative in accordance with our invention, but which has less structural simplicity than the forms already described, is shown in Fig. 4. In this arrangement the secondary winding 23 for supplying the lamps 5 is located between and parallel to two primary windings 24 and 25, the axes of the three coils being substantially coincident. The secondary winding for supplying the motor or motors 6 is shown as comprising a single coil 26, the axis of which is also coincident with the axes of the two primary coils and the other secondary coil and the said coil being also concentrically disposed around the other coils.

In the form of transformer shown in Fig. 5 the primary winding comprises two concentric coils 27 and 28, and the secondary winding supplying the lamps 5 is shown as comprising four coils 29, 30, 31, and 32, the coil 29 being outside and the coil 32 inside both primary coils and the coils 30 and 31 being located side by side between the two primary coils. The secondary winding for supplying the motors is here shown as comprising, two coils 33 and 34, which are parallel to each other and the axes of which coincide with those of the primary and the other secondary coils, but which are formed as flat coils and located at the respective ends of the other coils, the secondary coils for supplying the lamps and the primary coils being concentrically arranged.

It will of course be understood that the number of coils. and their relative arrangements may be greatly varied from what is here shown and that the primary and secondary windings may be interlaced to as great an extent as may be desired.

Our invention is adapted to transformers of the core type aswell as to those of the shell type, and this is indicated in Fig. 6, in which each side arm of the core 35 is provided with two primary coils 36 and 37, between which is located a secondary coil 38 in parallel relation with the coils 36 and 37 and with its axis coincident with the axes of said coils. The two. coils 38 are herev shown as connected in series with each other to supply the lamp-load 5. The winding for supplying the motor or motors 6 is here shown as comprising two coils 39, each of which surrounds one of the side portions of the core 35 and is located concentrically within the primary coils 36 and 37 and the secondary coil 38, these two coils being connected in series for supplying the motor or motors;

In Figs. 7, 8, 9, and 10 we have shown other forms of transformer-windings the secondaries of which are intended to supply both lamps and motors, so that changes in load on mary circuit, so that the magnetic leakage between the lamp-winding and the primary winding will be reduced to a minimum and will be less than the magnetic leakage between the motor-winding and the primary winding. With these arrangements of windings the motor and lamp loads are not interchangeable with reference to the two circuits.

In Fig. 7 the primary winding 40 is shown as comprising a single coil and the secondary winding as comprising four coils 41, 42, 43, and 44, all connected in series, the motor or motors 6 being connected across the outside terminals of the coils 41 and 44 and the lamps 5 being connected to the outer terminals of the coils 42 and 43.

In Fig. 8 the primary winding 45 is indicated as a single coil, and the secondary windings 46, 47, 48, 49, 50, and 51 are shown as connected in series, the motor or motors 6 being connected to the outside terminals of the coils 46 and 51 and the lamps 5 and 5 being shown as connected between the outer terminals of coils 47 and and the neutral or balancing conductor 52, which is in turn connected to the outer terminals of the coils 48 and 49. The inner terminals of the coils 48 and 50 are connected together, and the inner terminals of the coils 47 and 49 are also connected together, the arrangement being such as to permit of unbalancing the load on the three-wire circuit without unbalancing the voltage.

In Fig. 9 the primary winding is shown as comprising two coils 53 and 54, the secondary circuit supplying the motor or motors 6 as comprising three symmetrically-located coils 55, 56, and 57, all connected in series, and the an ill lllllll ll an ll'lll lllll cm s o 59, 60, and 61, all symmetrically disposed with reference to the primary winding and connected in series independently of the windings which supply the motor or motors.

In Fig. 10 we have indicated a single primary winding 62 and a secondary winding for supplying the motor or motors 6, comprising two coils 63 and 64, which are disposed with reference to the coils 65 and 66, which supply the lamps 5, and with reference to the primary winding 62 the same as the corresponding coils, (shown in Fig.'7,) except that the two secondary windings are here entirely independent of each other. Although the two sets of secondary coils are located at different distances from the primary coil or coils, the adjustment of magnetic leakage, as hereinbefore pointed out, is such as to insure reasonably satisfactory regulation, provided the secondary coils that are more remote from the primary winding are utilized for supplying the inductive load.

It will be understood that a very large number of combinations of coils could be made which would afford substantially the results secured by means of those here specifically illustrated, and we therefore desire it to be understood that our invention is to be construed to cover all such combinations and arrangements of coils as will permit of the operation of separate sets of translating devices in such manner that variations in load upon one circuit will produce either no effect or a minimum effect upon the voltage of the other circuit. It will also be understood that the number of secondary circuits may be greater than two and that they may carry the same kind of load, if desired; that the invention may be embodied in multiphase as well as in single-phase transformers of either the core type or the shell type, and that all of the combinations of coils here shown and described may be embodied in transformers of either the shell or the core type.

We claim as our invention 1. A transformer having a plurality of secondary windings the coils of which are symmetrically disposed with reference to the primary coils and to each other to avoid interfering leakage magnetic fields, whereby a variation in load on one of, the secondary circuits has substantially no effect on the voltage of another secondary circuit.

2. A transformer having a plurality of secondary windings the coils-of which are symmetrically disposed with reference to the primary coils and to each other to avoid interfering leakage magnetic fields so that when either or any of the separate secondary windings is employed to supply a load differing in characlllllllltldial... will..

windings, a variation in the load on one circuit will have substantially no effect on the voltage of another circuit.

3. A transformer having a plurality ofsecondary windings the coils of which are symmetrically disposed with reference to the pri- .metrically disposed with reference to each other and to the primary winding but at different distances from said primary winding, so that the magnetic leakage between one secondary winding and the primary winding will be less than that between another secondary winding and the primary winding.

5. A transformer having a plurality of secondary windings the secondary coils being symmetrically disposed with reference to each other and to the primary coils but at different distances from said primary coils, so that the magnetic leakage between one secondary winding and the primary winding will be less than that between another secondary winding and the primary, the former secondary winding being employed to supply loads requiring accurate voltage regulation and the latter to supply loads which are affected to a less degree by voltage fluctuations.

6. In a transformer for supplying both inductive and non-inductive loads, the non-inductive load being supplied from a three-wire circuit, secondary coils connected in series and symmetrically disposed with reference to each other and to the primary coils but at different distances from said primary coils, so that a variation in load on the inductive secondary circuit has relatively small effect on the voltageof the non-inductive secondary circuit and so that an unbalanced non-inductive load on the three-wire circuit does not materially unbalance the voltage thereof.

7. A transformer for supplying two circuits which has its secondary coils for supplying the respective circuits symmetrically disposed in unlike manner with reference to the primary coils, whereby the voltage of each circuit is substantially unaffected by variations in the load on, the other circuit.

In testimony whereof we have hereunto subscribed our names this 31st day of July, 1903.

JOHN S. PEUK. CHARLES LE G. FORTESOUE.

Witnesses:

HONORIA L. DOUGHERTY, BIRNEY HINES.

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