US1609141A - Voltage-regulating apparatus - Google Patents

Description

Nov. 30, 1926.

H. A. THOMPSON VOLTAGE} REGULATING APPARATUS Filed Feb. 15, 1925 INVENTORY l -Patented Nov. 3Q, 1926. g

UNITED STATES- 'HOWABD A. THOMPSON,

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PENNSYLVANIA, ASSIGNOR TO THE UNION I SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

'VOLTAGE-REGULATING APPARATUS. I

Application filed February My invention relates to voltage regulating apparatus, that is, to apparatus for supplying a substantially constant voltage toa-n electro-responsive device from a source of alternating current the voltage of which 'varies. a

.1 W111 descrlbeone form'and arrangement ofapparatus embodying my invention, and

of a stretch of railway will then point out the novel features thereof in claims.

' interposed in the two track rails.

The sect onAA-B is provided with trackway circuits intended for co-operation with train carried govermng'means responsive to the presence? of alternating current in the track rails. Since such governing apparatus is usually controlled by the trackway currents through the medium of suitable receiving apparatus carried on the train in advance it follows that meansof the forward axle, and since trains proceed in both directions over sect-ion A-B, must be provided for supplying the track section with alternating 7 current at each end of the section. I accordhand and right hand ends,

' the section and each having rail 1 of the associated section A-B in the the section with two track and T located at the left respectively, of

a secondary 4. constantly connected across the rails at the adjacent end of the section. 11 impedance 3 is interposed between the secondary 4 of each track transformer and one ingly provide transformers T winding I usual manner.

The supply of alternating current to the two track transformers-T and T is controlled by an auxiliary relay S controlled by means forming no part of the present invention and "omitted from the drawing for the sake of simplicity. This relay is so controlled that the relay is normally deenergized, but is energized when a train moving from ri ht to left enters section A-B and is retaine in the energized condition as long F as the train occupies current not shown 'the rails adjacent 11 is a second leg 13, 1925. Serial No. 8,918.

the section. As shown in the drawing, relay S is de-energized and under these conditions transformer T is deenergized but transformer T is energized, its primary winding 5 bein connected, over back contact 6-8 of relay with terminals J and-K of a suitablesource of alternating in the drawing. en relay S is energized, transformer T is deenergized but transformer T is then sn 4 plied with current from terminals J and C over front contact 6-7 of relay S. It will thus be plain cupied by a train-moving from left to right or is unoccupied, alternating current is supplied to the section from transformer T but that when the section is occupied .by a train moving from right to left the current is supplied to the rails by transformer T. 7

Section A-B is further provided with a track relay R arranged to receive energy from the track rails at a point adjacent transformer T. Due to the impedance of the track rails, and to the leakage through the track ballast, the difference of potential 'between the rails of the section A-B at point A will be considerably greater when the section is being supplied with alternating current from transformer T than when transformer T is supplying the current to the section. In the absence of any preventative means this widely varying difference of potential would be applied to the of the relay and might damage i This condition is undesirable and I therefore provide a regulating transformer D to maintain substantially constant-the voltage applied to the relay irrespective of ence of potential between rails at point A. This transformer D comprises a continuous magnetizable core 9'havmg a first leg 11 carrying a primary as desi tioned that for normal va e and proporues of potential terminals that when section A-B is 00- alternating v variations in the difierwinding 15 connected across pointA. Opposite to leg s difference between rails at point A, that is,

when transformer T is energized, the leg 10 ismagnetically saturated. The transformer D also comprises a magnetic leakage member 12 of magnetic material which member 7 forms a shunt around leg 11 of core 9. The member 12 is separated from the core 9 by two air gaps 1 3 and '13 and carries a secwinding 14 is opposed to ondary winding 14. A portion' of the flux created by winding 15 threads"winding '14 and induces therein an electromotive force. Secondary winding 14 is connected in series with relay R, and the relay and winding 14 are in turn connected across winding 15 in such manner that the voltage induced in the voltage applied towinding 15 from the track rails.

he parts are so proportioned that when section A-B is supplied with alternating current from transformer T the voltage across relay R is ofthe proper value for operating relay R and the magnetic flux in core 9 is of such value that leg 10 is saturated. Then if the voltage across the rails at point A increases, as by the energization of transformer T, the increased potential difierence between the rails at point A causes an increase in the current through winding 15 which results in an increased flux through leg 11. Leg 10 is, however, saturated and so the larger part of the additional flux threads through member 12 thus increasing the voltage induced in winding 14. Since this voltage opposes the voltage supplied from the rails, the result is that the increase in difference of potential eflective at the terminals of the relay is less than the actual increase in the'difi'erence of potential between ra1 s.

The ratio of turns in windings l5 and 14 is so chosen that a given increase in voltage applied to winding 15 causes an equal increase in the voltage induced in winding 14. With this arrangement it is plain that the voltage applied to the terminals of relay R is substantially constant over a wide range of variation in the potential difference between rails.

The relay B may be used to control apparatus not shown in the drawing, such as a trackway signal, in any desired manner.

I do-not in the present case, make any claim for the combination of the transformer D with the track rails and track relay of a ra' way signaling system, such invention bein claimed in my co-pending application filed on the 15th day of August, 1924, Serial No. 732,196, for railway traific controlling apparatus.

I clalm is:

Although I have herein shown and de-- scribed only one form and, arrangement of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the vention.

Having thus described my invention, what 1. In combination, a source of alternating current having 'a'variable voltage, an electroresponsive device supplied with current from said source, a continuous magnetizable core having a first leg carrying a primary winding connected in parallel with said de vice, and having a second leg that is magnetically saturated when the voltage of said source is at normal value, a magnetizable leakage member shunting said first leg, and

a secondary winding on said member and connected in series with said device in such manner that the voltage induced in said secondary is opposed to the potential applied to the device from the source.

2. In combination, a source of alteriiating current having a variable voltage, an electro-responsive device supplied with currentfrom said source, a transformer comprising a core having a first leg carrying a primary winding connected in parallel with said device and having a second leg that is mag- 'netically saturated at normal value of the voltage of said source, a magnetic leakage member shunting said first leg, and a secondary winding on said member series with said device.

3. Voltage regulating apparatus comprising a magnetizable core carrying a primary winding and having a leg which is saturated at the normal voltage applied to said priconnected in mary winding, a magnetic leakage member shunting the part of sald core which carries the primary winding, and a secondary winding on said leakage member connected with said primary winding but so wound that the 4 voltage induced therein by current in the primary winding opposes the voltage applied to the primary winding.

In testimony whereof I affix my signature.

HOWARD A. THOMPSON.

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