US3263195A - Autotransformer - Google Patents

Description

July 26, 1966 c. B. VAUGHAN 3,263,195

AUTOTRANSFORMER Original Filed Jan. 15, 1962 INVENTOR.

N CARROLL B. M4UGHAN .rate auto transformer for each output channel.

United States Patent 3,263,195 AUTOTRANSFORMER Carroll B. Vaughan, East Orange, N.J., assignor to The Bendix Corporation, a corporation of Delaware Original application Jan. 15, 1962, Ser. No. 166,224.

Divided and this application Aug. 6, 1963, Ser. No. 300,312 I 2 Claims. (Cl. 336-45) The present application is a division of US. application Serial No. 166,224, filed January 15, 1962, by Carroll B. Vaughan and assigned to The Bendix Corporation and the invention relates in general to an autotransformer and more particularly to a multi tap auto transformer having a plurality of independently variable output terminals. I

Heretofore, a number of devices were available to supply from a single alternating current source, a plurality of independently adjustable alternating currents on a plurality of channels. These devices used a sepa;

Or, i there was a predetermined relationship between the alternating currents to be provided at two channels, a single auto transformer was used, with two brushes mechanically linked together.

The present invention is a multi independent brush auto transformer that provides a plurality of independently adjustable alternating currents on a plurality of channels with the use of only a single magnetic core and a single source of alternating current. Some of the advantages of the novel multi independent brush auto transformers are compactness, efficiency, and the ability to avoid saturation of the core when the output voltage is half wave rectified.

The ability to avoid saturation of the magnetic core is inherent to the multi tap. auto transformers. Saturation occurs when the output of an auto transformer feeds a half wave load. However, the multi tarp auto transformer can feed several half wave loads, one on each of its output terminals. The half wave loads can be adjusted so that the loads at some terminals will be of one polarity while the load at the other terminals will be of the other polarity, thus avoiding saturation of the magnetic core.

An object of the invention is in the provision of a novel multi channel power supply.

Another object of the invention is in the provision of a novel multiple tap auto transformer having several output channels, each output voltage being independently adjustable.

Another object of the present invention is in the provision of a-novel alternating current power supply having a multiplicity of output terminals; the voltage at each terminal being continuously adjustable and adjustable independently of each other.

Another object of the invention is in the provision of a novel alternating current power supply having a plurality of independently adjustable output voltages taken off a single core auto transformer. I

Another object of the present invention is in the provision of a novel auto transformer having a plurality of independently adjustable output terminals to provide a compact alternating current power supply.

Another object of the invention is to provide a novel independent brush auto transformer having a plurality of output terminals to avoid saturation of the core during half Wave loading of the outputs.

These and other objects and features of the invention are pointed out in the following description in terms of the embodiment thereof which is shown in the accompanying drawings. It is to be understood, however, that the drawings are for the purpose of illustration only ice and are not a definition of the limits of the invention, reference being had to the appended claims for this purpose.

FIGURE 1 is an exploded view of the operative parts of a multi variable brush auto transformer of the present invention.

FIGURE 2 is a detailed view of a spring loaded brush and brush holder of the multi variable, brush auto transformer shown in FIGURE 1.

The present invention relates to a novel multi inde pendent brush auto transformer (or alternating current power supply, one embodiment ofwhi ch is shown by FIGURES 1 and 2.

Referring to FIGURE 1, there is shown therein an exploded view of the operative parts of the novel multi independent brush auto transformer. In particular, a toroid 201 is wound with a wire 202 in a single layer over its outside cylindrical surface so as to provide an exposed segmental wire contact or commutator surface 203 of a wire wound toroid, as described and claimed in a copending U.S. application Serial No. 315,735, filed September 25, 1965, by Carroll B. Vaughan as a division of US. application Serial No. 166,343, filed January 15, 1962 by Carroll Byrd Vaughan, now US. Patent No. 3,213,520 granted October 26, 1965, to Carroll B. Vaughan for method for preparing a toroid core, and assigned to The Bendix Corporation, assignee of 'the present application. In the FIGURE 1, the wire is shown covering approximately 330 of the outside surface.

Two ends 218, 219, of the wire 202 to be connected to an alternating current source are brought out to two terminals 220 and 221 on a toroid frame (not shown). A ring gear 222 (having an inside diameter of, for example, approximately 3% inches, and an outside diameter of, for example, approximately 4 /2 inches with 10 teeth per inch on its outer diameter) fits over the toroid 201. The toroid 201 is securely mounted on a rigid frame (not shown) and has an outside diameter of, for example, approximately 3 inches.

The toroid 201 projects from the rigid frame in a spaced concentric relation within the larger annular openingof the ring gear 222. The ring gear 222 is rotatably positioned, in a supporting member of a conventional type formed of a suitable electrical insulating material and carried by the rigid frame.

A brush 223, held by a brush holder 226, makes a variable operative electrical contact with commutator sur- 7 face 203 and is mounted in a slot 224 located in the wall of the gear 222 and is capable of moving radially in the gear under the constraint of the slot 224, spring loading means 225, and the brush holder 226. A detailed view of the spring loading 22'5, brush 223, and brush holder 226 is shown in FIGURE 2. The brush 223 is, for example, approximately by ,4 by of an inch,and the ring gear 222 has a width, for example, of of an inch. A flexible metal pigtail conductor 226 leads from the brush holder 226 to the metal ring gear 222. Thus, there is a conducting path from the input wire terminals 220 and 221, of the toroid 201 through the toroid windings 202 and commutator surface 203 to the brush 223, brush holder 226, and pigtail conductor 226' into the ring gear 222.

Ring gear 222 rides next to a wrinkle spring washer 227 made of a conducting material and supported in a fixed relation by the supporting member of insulating material carried by the rigid frame (not shown). A pigtail conductor 229 is soldered to the wrinkle washer 227 and brought out to a terminal lug (not shown) on the frame (not shown). An insulating ring washer 228 also supported by the supporting member of the frame (not shown) and having the same dimension as the ring gear 222 is then stacked next to the wrinkle spring washer 227.

The ring gear 222 may be adjusted in slidable relation to the Wrinkle spring washer 227 which serves to hold the ring gear 227 and washer 228 under spring tension in a compact relation in the assembled device.

What has been just described, namely the ring gear 222 brush 223, wrinkle washer 227, and insulating ring 228 comprise one of many assemblies which are to be mounted in the supporting member of the rigid frame (not shown) of the multi independent brush auto transformer. In the present embodiment, 10 such assemblies are installed around the center toroid 201. It should be noted that the multiple brush auto transformer may comprise any number of outputs, depending on the length of the toroid 201 and the number of assemblies.

The toroid 201 is securely mounted on the rigid frame (not shown) and surrounded by a housing (not shown).

The wire 202 on the toroid 201 is connected at its ends 218 and 219 to two terminals 220 and 221 mounted on the outside of the frame and housing.

The brushes 223 are positioned by rotation of the ring gear 222. This gear 222 is rotated by means of a worm gear 230 mounted on a shaft 231 terminating in a crank 232 which may be of a suitable electrical insulating material. By revolving the crank 232, the worm gear 230 causes the ring gear 222 to rotate in the suitable supporting means carried by the rigid frame and surrounded by the housing (not shown).

The location of the brush 223 on the toroid commutator surface 203 is proportional to the number of revolutions of the crank 232 and is indicated on. a flat slide rule indicator 235. A string 237 winds and unwinds with the direction of rotation of the crank 232. The string is lead over a small pulley 237A and actuates pointer 236 on the slide rule indicator 235. A spring 239 or other restoring force returns the pointer 236 to the zero position when the brush is at a minimum position. As the crank 232 is turned, a rack and pinion arrangement advances a slotted shaft 234 with an eyelet 233 to guide the string 237, in order that the string will not slack up on the crank shaft 232, but will lay in even turns. There may be a plurality of such gear and brush assembly, and there is one indicating device for each gear and brush assembly and each slide rule indicator 235 may be calibrated in either percentages or proportional to the output voltage.

Although only one embodiment of the invention has been illustrated and described, various changes in the form and relative arrangement of the parts, which will now appear to those skilled in the art may be made without departing from the scope of the invention. Reference is, therefore to be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. A multi tap auto transformer comprising a toroid core of magnetic material; a wire winding on said core of a commutator type; a plurality of adjacently placed brush groups each including a rotatably positionable ring gear mounted concentrically on the toroid; a conducting wrinkle ring washer mounted concentrically on the toroid and adjacent to and in electrical contact with the ring gear; an insulating ring washer mounted concentrically on the toroid and adjacent to the wrinkle ring washer; a brush carried on the ring gear and extending radially on said gear to make contact with the commutator surface on the wire winding; and operator-operative positioning means for rotating said ring gear about the toroid to adjustably position :the brush carried by said ring gear relative to said commutator surface on the wire winding.

2. The combination defined by claim 1 including a worm gear operatively connected to the ring gear, an operator-operative shaft on the worm gear; a string means having two ends; one end of said string means being attached to the shaft and the other end of said string means being attached to a spring loading means, an indicating member located at a fixed position on the string means, intermediate the ends thereof; an indicating panel located in spaced relation to said indicating member whereby upon the worm gear being actuated to adjustably position the ring gear and the shaft of the worm gear being rotated, the string means may be effectively wound about said shaft so as to displace said string and the indicating member fixed thereto, said displacement of the said indicating member being observable on the indicating panel, and said string means and indicating member displacement being proportional to the adjusted position of the ring gear.

References Cited by the Examiner UNITED STATES PATENTS 2,061,452 11/1936 Comstock et al. 336l49 X 3,132,627 5/1964 Lesatz l16-l24 FOREIGN PATENTS 263,829 7/1927 Great Britain.

LARAMIE E. ASKIN, Primary Examiner.

JOHN-F. BURNS, Examiner.

C. TORRES, Assistant Examiner.

Claims (1)

1. A MULTI TAP AUTO TRANSFORMER COMPRISING A TOROID CORE OF MAGNETIC MATERIAL; A WIRE WINDING ON SAID CORE OF A COMMUTATOR TYPE; A PLURALITY OF ADJACENTLY PLACED BRUSH GROUPS EACH INCLUDING A ROTATABLY POSITIONABLE RING GEAR MOUNTED CONCENTRICALLY ON THE TOROID; A CONDUCTING WRINKLE RING WASHER MOUNTED CONCENTRICALLY ON THE TOROID AND ADJACENT TO AND IN ELECTRICAL CONTACT WITH THE RING GEAR, AN INSULATING RING WASHER MOUNTED CONCENTRICALLY ON THE TOROID AND ADJACENT TO THE WRINKLE RING WASHER; A BRUSH CARRIED ON THE RING GEAR AND EXTENDING RADIALLY ON SAID GEAR TO MAKE CONTACT WITH THE COMMUTATOR SURFACE ON THE WIRE WINDING; AND OPERATOR-OPERATIVE POSITIONING MEANS FOR ROTATING SAID RING GEAR ABOUT THE TOROID TO ADJUSTABLY POSITION THE BRUSH CARRIED BY SAID RING GEAR RELATIVE TO SAID COMMUTATOR SURFACE ON THE WIRE WINDING.

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