US1404442A - Means of producing constant-current regulation of generators - Google Patents

Description

O. A. KENYON.

MEANS OF PRODUCING CONSTANT CURRENT REGULATION OF GENERATORS. APPLICATION FILED JAN. 22. 1918.

III IIIII Patented Jan. 24, 1922.

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Inventor.

J1 ttorney.

UNITED STATES OTIS ALLEN KENYON, 01' NEW YORK, N. Y.

MEANS or raonucmo cousrmr-cunmr murarrou or onuuaa'roas.

Specification of Letters Patent. Patented J an, 24, 1922.

Application filed January 22, 1918. Serial ll'o. 813,187.

To a]? whom it may cont-em:

Be it known that I, OTIS A. KENYON, a citizen of the United States, residin at New York city, in the county of New ork and State of New York, have invented certain new and useful Improvements in Means of Producing Constant-Current Regulation of Generators, of which the following is a specification.

My invention relates to an improved means of producing constant-current regulation in a direct current separately excited generator, and the invention consists of the parts and the constructions, arrangements and combinations of parts which I Wlll. here inafter describe and claim.

In the accom anying drawing forming part of this speci cation; Figure 1 illustrates more or less diagrammatically, a differential regulator circuit system desigied primarily for arc welding machines. igure 2 illustrates a modified arrangement, to be hereinafter disclosed.

In the said drawing 1 represents the armature of a constant-current generator; 2 is the shunt field thereof; 3, 14 and 15 are welding arcs in the main line; 4, 5 represent a carbon pile of suitable construction; 7 and 8 are plungers arranged in parallelism; and 6 is a yoke or part having stems passing through the lungers and having an intermediate mem er 6 which bears against the Carbon pile; 9 is a series coil; 10 is a separately excited coil; 11 is a rheostat; and 12 is a separate source of electric energy.

For the purpose of electric arc welding, it is desirable to employ a source of constant-current, which is capable of maintaining a high degree of current regulation under extremely large and sudden variations in the current. It is also desirable to have a suitable means for adjusting the value of the current over a wide range.

Constant-current generators such as are used for series are 11 hting, and which are generally known in t e art, are not suited for arc welding, because the means employed for maintaining the constant-current characteristics are too slow to prevent large momentary variations in the current, that will injure the metal.

My present invention has particular reference to an improved means of (producing constant-current regulation in a irect current shunt wound generator. Preferably, I

employ a generator with a thoroughly laminated magnetic circuit constructed with interpole windings so as to obtain satisfactory commutation. The field of the generator I propose to excite from a separate source, preferably low in voltage and insert 1n series with said excitation winding, a resistance, the value of which is varied by means actuated from the main line current.

1 am aware that a similar method has been used and is known in the art for the re lation of current in charging batteries. However, in batter work, there are no sudden variations, eit er in the current or in the E. M. F., and the important function of such a regulator is to, produce a very irccurate and permanent degree of regulaion.

In arc welding, a regulator is" re uired which will maintain the constant va no of current under widely differing E. M. F.s, which change suddenly from one value to another. Accuracy and permanency of adjustment are of no specia value.

Heretofore, in the construction of regulators of the character described, the magnetic circuit of the re lator has been so constructed as to r uce a constantpull over the entire wor 'ng range and which is usually opposed b a constant force of gravity and dampe by a dashpot so as to prevent overswinging; it is also the practice to multiply all motions by some system of leverage.

In case of arc welding, such construction as last referred to, is fundamentally wrong, and produces results that cannot be tolerated if the best resultsare to be expected, as will be understood from the following:

First of all it is neceary to reduce the mas of moving parts to a minimum and,

therefore, it is desirable to eliminate all levers and abolish dashpots and the use of gravity as an opposing force. It is also desirable to em loy a means of adjusting the operating point of the regulator so that it can be set to maintain a current in the main circuit at any desired value.

A leading object .of the present invention is to provide a means of ad usting accurately over a wide range the current atwhich the regulator operates, and in the illustrated embodiment of my invention, this idea is carried out, by u a carbon pile for the resistor in series wit the excitation circuit,

' stant-current generator, 9 is the series coil of the regulator, and 10, the separately excited coil thereof, it will be seen that the field 2 of the generator is designed to be excited from the separate source, 12, and connected in series with the carbon pile resistance, 4, 5. The value of the current in the field, 2, is determined by the pressure exerted by the yoke, 6, on the pile, 4, 5, and this in turn is determined by the difference in pull exerted on the plungers 7 8. The pull on the plunger, 8, of the coil, 10, is constant, because said coil is connected across the source of constant-potential, 12. The pull of plunger, 8, is transmitted through yoke 6, and projection, 6', and acts to compress the carbon pile, 4, 5, thereby allowing the field current of winding, 2, to increase. If this increase in field current and the consequent increase in E. M. F. of the generator results in an increase in the line or welding current, the pull of coil 9, will increase and by action on the pile in opposition to coil, 10,

cause the E. M. F. of the generator to decrease until the adjusted value of line current is established.

In this manner any change in the line resistance or counter E. M. F. will be instantly counteracted by the automatic re-adjustment of the pressure on the pile, 4, 5, to give the exact balance of the two coils, 9 and 10.

By adjusting the rheostat, 11, in series with the coil, 10, and which operation will be understood by those skilled in the art, the pull of the coil, 10, can be varied over any desired range and therewith the current in the main circuit supplied by the generator armature, 1, can be varied at will. From this description it will be apparent that I have devised a means of adjusting accurately over a wide range, the current at which the regulator operates and that these means include two coils and means controlled by the differential action thereof to regulate the current in the welding circuit, one of the'coils being excited from a source of constant-potential and the other carrying the main welding line current which is to be regulated.

Fig. 2 shows a different mechanical arrangement of the same operating parts as shown in Fig. 1. Instead of usingba fixed yoke, 6", rocker arm, 19, pivotallyalanced at 18 is'used. The plunge-rs hang vertically from the ends of this rocker arm and swing in one direction or the other, according to the difierential pull which is transmitted to the pile through pin, 17 Where heavy plungers are used, this mode of construction will greatl reduce the frictional resistance, and

. to a li e extent improve the closeness of regulation. 7

Having thus described my invention what I claim as new and desire to secure by Letters Patent is 1. An electric circuit, a solenoid coil connected in series therein, a constant potential circuit, a solenoid coil in series therein, and means controlled by the differential action of said coils to regulate the current in the first mentioned circuit.

2. An electric circuit, a solenoid coil connected in series therein, a constant potential circuit, a solenoid coil in series therein, and means for adjusting the current in said constant potential circuit, and means controlled by the differential action of-the said coils to regulate the current in the first mentioned circuit.

3. An electric generator having a sepa-. rately excited field winding, a solenoid coil in series in the generator main circuit, a constant potential circuit and a solenoid coil in series therein, and means controlled by the differential action of the said coils for varying the value of the current in the field winding of the generator.

4. An electric generator having a sepa rately excited field winding, a solenoid coil in series in the generator main circuit, a constant potential circuit and a solenoid coil in series therein, means for adjusting the current in the constant potential circuit, and means controlled by the differential action of the said coils for varying the value of the current in the field winding of the generator.

5. An electric generator having a separately excited field winding, a device for varying the resistance of the excitation circuit, a constant potential circuit, a solenoid coil excited thereby and adapted to actuate said device to maintain the excitation current at a certain value, and electro-responsive means controlled by the generator current and adapted to oppose the action of the said solenoid.

6. An electric generator having a separately excited field winding, a device for varying the resistance of the excitation circuit, a constant potential circuit, a solenoid excited thereby and adapted to actuate said device to maintain the excitation current at a certain value, and means for adjusting this value, and electro-responsive means controlled by the generator current and adapted to oppose the action of the said solenoid.

7. An electric generator having a separately excited field winding, a carbon pile in series in the excitation circuit, a solenoid coil in series in the generator main circuit, a constant potential circuit and a solenoid coil in series therein, and means for varying the pressure on the carbon pile by the differential actionbetween the said coils.

8. An electric generator having a separately excited field winding, a carbon pile in series in the excitation circuit, a solenoid coil in series in the generator main circuit, a constant potential circuit and a solenoid coil in series therein, means for adjusting the current in the constant potential circuit, and means for varying the pressure on the said carbon pile by the difierential action between the said coils.

9. An electric generator having a separately excited field winding, a carbon pile adapted to vary the resistance of the excitation circuit, a constant potential circuit, a rheostat in series therein, two solenoid coils, one in series in the generator main circuit, the other excited by the constant-potential current, and means controlled by the differential action of said coils, to vary the pressure on said carbon pile.

In testimony whereof I aflix my si ature.

OTIS ALLEN KEN ON.

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