US2062720A - Regulating transformer - Google Patents

Description

Dec. 1, 1936. LEISCHNER 2,062,720

REGULATING TRANSFORMER Filed July 9, 1935 3 Sheets-Sheet l 70 6190/ fle/lacfiner,

Inventor B' QQW Dec. 1, 1936. G LElscHNER 2,062,720.

REGULAT ING TRANSFORMER Filed July 9, 1935 5 Sheets-Sheet 2 Fig.4-

Dec. 1, 1936.

G. LEISCHN ER REGULATING TRANSFORMER Filed July 9, 1935 5 Sheets-Sheet 3 @W uh 0, 3,82. I

/n ventor: V Geo/"9 Fig.9 4

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Patented Dec. 1, 1 936 UNITED STATES PATENT OFFICE Georg tfit'iiifdatittttifth'ldtil Application July 9, 1935, Serial No. 30,570

InGermany July 24, 1934 8Glaims.

The present invention relates to a regulating transformer. One use of such a transformer consists, e. g. in maintaining the constancy of the potential of an alternating current net, notwithstanding varying load or fluctuations in feed po- 'tential. Another use is the generation of a variable potential)v for instance, for feeding the motors of electric locomotives.

For the purpose of regulating alternating potentials, generally transformers are employed,

in which one coil is provided with taps being connected with contacts, with the result that difierent lengths of this coil can be interpolated. When passing from one contact to the next followins one, the electric current must ordinarily be inter rupted for a short period. If such an inter= ruption is to be avoided, the connection with the next '-'succeeding contact must be made before that with the-preceding one is broken, in con nection with which that part of the coil, being situated between the two contacts, is short-cir cuited. Powerful short-circuit currents are produced thereby in this part of the coil, causing an inadmissible heating of the coils, the interruption of which produces destructive arcs.

li'he present invention relates to a regulating transformer in which these defects have been avoided by causing the iron core to comprise a plurality of partial cores and causing'the regulatlng coil to so contact with a contact slide that,

when two adjacent contacts are short-circuited.

- the short-circuited portion encompasses merely one partial core and the flux, which would otherwise pass through this partial core, is forced on on to the other partial cores.

, Further advantages, characterizing the present invention, will appear more fully from the following description, particularly when considered in conjunction with the accompanyins drawings,

which are forming part thereof.

Fig. 1 is a diagrammatic side. elevation of a part of a regulating transformer in accordance with the present invention.

Fig. 2 represents a diagrammatic plan view of the identical part.

Fig. illustrates an arrangement with five partial c and a star-shaped contact slide.

Fig. 4 is a side elevation of a form of performance of a regulating transformer in accordance 50 with the present invention.

Fig. 5 is a cross-sectional view along the line 5-5ofFig.4. v

Fig. 6 is a side elevation of a further'form or performance ,in section along the line H of Fig. 7 is a cross-sectional view along the line 1-1 of Fig. 6. s

Fig. 8 represents an arrangement inordance with Fig. 5, in which taps on the re ting coil are made to pass through between the par tial cores.

Fig. 9 details an arrangement corresponding to Fig. 7, in which taps on the regulating coil are made to pass through between the partial cores.

In the regulating transformer, represented in Figs. 1 and 2 only partly and diagrammatically, the iron core may be of any desired shape, such as is known in the art in connection with transformers. From these known forms the core. or the regulating transformer in accordance with the present invention difiers, however, in so far as the portion, encompassed by the regulating coil ii, is sub-divided into two or more partial cores, i. e. in thecase of Figs. 1 and 2, into two partial cores a1 and 02, being separated by the airgap Ii. Within this air gap ll the contact slide i2 is so disposed, that it allows of'being dia placed in a longitudinal direction of the core and that the contact pieces I 3, attached to the contact slide l2, are made to establish contact on the inner face of the regulating coil alternately with the one or the other winding.

If the contact slide is made to occupy the position as represented in Fig. 1, in which both contacts it are touching the regulating coil, the one winding half, encompassing the partial core or, will then be short-circuited and the flux will be forced out therefrom. If the contact slide is further displaced so as to establish contact with the next winding, the winding-half, encompassing 35 the partial core 02, will be short-circuited and the flux forced out therefrom and so on, until the contact slide has covered the whole of the path.

It is, however, advantageous, to split up the core into more than two partial cores, e. g. into tour, w a'nd'to cause the contact slide to be cross-shaped,' as shown in Fig. 5. In connection with more than four partial cores the contact slide should be starshaped, as shown in Fig. 3. The width of the contact pieces IS in the direction of the core, must then always be so selected, that always only two contacts touch the regulating coil, because otherwise the flux will be forced out from more than one partial core. I

In the Figs. 4 andf5 one form 'oiperformance of a regulating transformer in accordance with the present invention has been represented. The iron core is made to carry on one of the limbs the primary coil l5 and on its other limb the regulatinc .0011 It. The core encompassed by the regu- 6d lating coil consists of four partial cores, oi, as, as. and m. In the cross-shaped air-gap between these four partial cores the contact slide I1 is slidably disposed in the direction of the longitudinal axis of the regulating coil. This contact slide II touches the regulating coil I6 inwardly by means of its four contact pieces l8, I, III, and II. In order to represent the position of the contact slide, Fig. 4 is made to show the arrangement in section at the point, where the contact slide is situated. It will be seen without any diillculty, that in the position of the contact slide indicated in the drawings, the contact pieces II and ii are establishing contact with the regulating coil, whereby a short-circuit, encompassing the limb at, will be produced. This will cause the flux, passing through the limb at at uniform distribution, to be forced off to the limbs or, as, and as, so that in the short-circuit, encompassing the limb in, no shortcircuit currents, endangering the arrangement, will be produced. If the contact slide is moved further in an upward direction, the contact between the contact piece It and the regulating coil will be broken in the first instance and, in consequence of a further movement, the contact between the contact piece is and the regulating coil willbeclosed. Inthis positiontheparttal limbai will then be encompassed by a short-circuit and the flux will be forced away from this limb.

For the purpose of shifting the contact slide, a rack 22, in which a toothed wheel 28, actuated by means of a crank 24, is made to engage, is passed through the limb of the iron core in anaxial direc-' tion. A sliding contact 25 is made to serve as current feed to the contact slide. The variable potential produced can be taken oi! between one of the binding posts 26 and the binding post 11. It is a matter of course, that the arrangement may also be used as auto-transformer and that the primary potential can be connected with the two binding posts. The primary coil II can, in this instance, be dispensed with. K

The contact slide can also be so dispoud, that it establishes contact with the outer face of the regulating coil of the inner face. In this case the magnetic flux return conductors require to be sub-divided and the separate contact pieces of the contact slide to be passed through between the former.

An arrangement of this kind is shown in Figs. 6 and 7. The iron core is so composed of four bilimbed iron cores, that the four limbs or. as. as,

and at are forming a whole being encompassed by the primary coil 28 and the secondary winding II. Outside of these two .windings the limbs bl, ba, ha, and b4 have been annularly disposed. Around the limbs bi-la a ring as, serving as contact slide, has been provided and is adapted to be displaced in the direction of the axis of'symmetry of the arrangement. From this ring four contact arms 3|, 3!, 38, and 84, provided with contact pieces 35, II, 81, and 38, are made to pass through between the cores in to D4, said contact pieces being made to contact with the coil 2.. In the position of the contact slide II as indicated in Fig. 6, the contact arms it and II are made to establish contact with the regulating coil. This will cause a short-circuit, encompassing the limb In, to be produced and the flux, passing through this limb at uniform distribution, will be suppressed. In conformity therewith, the flux in the limbs b1, b1, and D4 will be increased. Four screw spindles ll, 40, 4i, and 42 may be made to serve for displacing the contact slide 3|.

Instead of providing the contact slide w th contactarmswhicharemadetopassthroughthe cores, it will be possible to provide in the forms of the invention as shown in Figs, 1 to 5, as well u in the form of the invention as shown in Figs. 6 to 7, also on the regulating coil tappings passing through between the partial cores and establish-.

ing contact with the contact pieces of the contact slide, as shown in Figs. 8 and 9. The contact slide is also adapted, apart from the displacement in direction of the axis of the regulating coil, to :zgcribe an eccentric motion round the regulating It is, of course, understood, that in all the arrangements described, the direction of theenergy may be reversed and that the regulating coils may be connected with the source of supply as primary coils, and the fixed coils with the point of consumption as secondary coils.

I wish it distinctly to be understood. that I do not desire my invention to be limited to theexact 30 skilled in the art.

What I claim, is:

l. A regulating transformer, comprising an iron core, a regulating coil, a contact slide and contact pieces, the part, encompassed by the regulating coil, consisting of a plurality of partial cores, the contact slide being moveably dilposed between the partial cores. the contact pieces on the contact slide being so arranged, that they establish contact with the inside of the regulating coil'and that the short-circuit, produced by the contact of two points of the regulating coil, encompasses one partial core.

2. A regulating transformer, comprising an iron core, a regulating coil, a contact slide and contact pieces, the part of the iron core. encompassed by the regulating coil, being made to consist of a plurality of partial cores annularly disposed, the star-shaped contact slide being moveably disposed between the partlal cores, the contact pieces on the contact slide being so disposed. that they establish contact with the regulating coil on the inside and that the short-circuit, produced by the contact of two points of the regulating coil, encompasses one partial core.

3. A regulating transformer, comprising an iron core, a regulating coil, a contact slide and contact pieces, the part of the iron core enemipassed by the regulating coil being made to consist of four partial cores,'the cross-shaped contact slide being moveably disposed between the partial cores, the contact pieces on the contact slide being. so disposed, that they establish contact with the regulating coil on the inside and that the short-circuit, produced by the contact of two points of the regulating coil, encompa-es one partial cone.

4. A regulating transformer, comprising an iron core, a regulating coil, a contact slide and contact pieces, the part of the iron core encompassed by the regulating coil consisting of a plurality of partial cores, the contact slide being moveably disposed between the partial cores, the contact pieces on the contact slide being so disposed, that they establish contact with the Mlllating coil on the inside and that the short-circuit, produced by the contact of two contact pieces connected with the regulating coil, encompasses one partial core.

5. Regulating transformer, comprising an inn core, a regulating coll, a contact slide and contact pieces, the part of the iron core, situated outside the regulating coil, consisting of a plurality of partial cores, the contact slide outside the partial cores being mcveably disposed, the contact pieces being so disposed on the contact slide that, passing through between the partial cores, they establish contact with the outside of the regulating coil and that the short-circuit, produced by the contact of two points of the regulating coil, encompasses one partial core.

6. Regulating transformer, comprising an iron core, a regulating coil, a contact slide and contact pieces, the part of the iron core, situated outside the regulating -coil, consisting of a plurality of annularly' disposed partial cores, the contact slide outside the partial cores being moveably disposed, the contact pieces on the contact slide being so disposed, that they are made to pass through between the partial cores and establish contact with the regulating coil on the outside. and that the short-circuit, producedby the contact of two points of the regulating coil, encompasses one partial core.

7. Regulating transformer, comprising an iron core, a regulating coil, a contactslide andcontact pieces, the part of the iron core situated outside the regulating coil consisting of a plurality of partial cores, the contact slide outside the partial cores being moveably disposed, the contact pieces being so disposed on the contact slide, that they establish contact with the contact pieces, connected with the regulating coil, from the outside and that the short-circuit, produced by the contact of two Contact pieces con nected with the regulating coil, encoinpasses one partial core.

8. A regulating transformer comprising a plurality of. partial cores, over which the power flux generated by a transformer is distributed, a regu lating coil and a contact slide, at least one of the cores carrying the regulating coil, the contact slide engaging between the partial cores provided with at least two electrically connected contacts which contact with the regulating coil encompassing the core at two diametrically opposite points, in such manner that the thereby resulting short circuit encompasses only one of the cores partially traversed by the main current flux.

GEORG LEISCHNER.

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