US2201863A

US2201863A - Remote control system

Info

Publication number: US2201863A
Application number: US724843A
Authority: US
Inventors: Benjamin W Jones
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1934-05-10
Filing date: 1934-05-10
Publication date: 1940-05-21
Anticipated expiration: 1957-05-21

Description

May 21, 1940. B. -w. JONES REMOTE CONTROL SYSTEM v Filed May 10, 1,934

Fig. L

Fig. 2

s 6 :w WOIJ tW mm mm m 8 B 8 .8 tag Attornqg- Patented, May 21, 1940' nEMo'rE CONTROL SYSTEM Benjamin W. Jones, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application May 10, 1934, Serial No. 724,843

a Claims.- (01. 171 -312 My invention relates to remote control systems. It is an object of my invention to provide means responsive to predetermined closing and opening operations of a load circuit for controlling the source of supply to which said load circuit is connected.

It is a further object of my invention to provide a power system in which a characteristic of the generator may bealtered by momentarily closing the load circuit a predetermined number of times.

It is a further object of my invention gradually to vary a characteristic of a generator in a system such as described above through the agency of interconnected time element relays, the time differential of the operation 01 two of said relays determining" the length of time the voltage varying means is energized.

Further objects of my invention will become apparent from a consideration or the following prises. a generator I6, a driving motor II niechanically connected thereto and a load circuit I2, I3 electrically connected thereto. The load circuit is employed tor connecting a load device to the generator, and in the particular arrangement illustrated the load comprises a welding are which may be established between an electrode l4 and the work I6.

The loari circuit l2, I3 forms the secondary of a transformer l6 whose primary I1 is connected to one phase '01 a polyphase source I6 through conductors l3 and 20, the operating coil 2| of a relay 22 and a conductor23. The,motor II is connected through conductors 24, a switch 26 and conductors 26 to the source of supply I8. The switch-25 is an electromagnetic switch having, an operating winding 21 which is connected across one phase of ,the source I6 when a starting switch 28 or contacts 29 of relay 22 are closed. -The closure of contacts 23 completes the following circuits from one conductor of the source ot supply'glt, through conductor '33, con-' 'ta'cts of stop switch 3|,

conductors

32 and 33, contacts 29 of relay 22, conductors 34 and 36, contacts 36 of relay 31, conductor 36, operating coil 21 of switch 25 and one of conductors 26 to another conductor of the source of supply III.

The starting switch 28 is in shunt to the contacts 26 of relay 22 and its closure will also energiae follows:

tors

32 and 33, contacts 40, conductor 35, conthe operating 001121 of switch 26 through a circuit comprising conductor 30,

switches

31 and 28,

conductors

33, 34 and 35, contacts 36 of relay 31, conductor 38, operating coil 21 of switch 26 and one of the-conductors 26. The closure of switch 25 closes its holding contacts 40 which completes a holding circuit tor the switch 26 as from one terminal of the source I6 through conductor 30, stop switch 3|, conductacts 36 of relay 31, conductor 33, operating coil 21 of switch 25, and one, of the conductors 26 to .another terminal of the source of supply I8.

The operating coil 4| of relay 31 is connected across the source of supply 42, 43 through the following circuit: from conductor 42, through conductor 44, the upper contacts 45 of relay 46,

conductors

41 and 46 to the other terminal 43 of the source of supply. Relay 31 is of the time delay type and, in the particular form illustrated,

comprises a dash-pot 49 one element of which is positively connected to the movable contact 36 which is yieldingly connected through a spring 50 to the movable element of the relay 31. Thus, when the relay 31 is energized the contacts 36 move slowly relatively to one another under the controlling influence of the dash-pot 43, and after a'predetermined lapse of time the contacts \36 open thereby deenergizing the operating coil 21 of switch 25 by means of which motor II is connected to the source of supply I8.

two positions one of which corresponds to open circuit normal voltage conditions on the load circuit, in which contacts 46 areclosed, and the other of which corresponds to closed circuit or operating conditions on the load circuit, in which contacts 52 are closed. Thus, when the electrode I4 does not make an actual engagement or an arcing engagement with the work I5, e

relay 46 completes a circuit. through contac 45, and when the electrode is touched to the work I5 6:- a welding arc is established therebetween, the relay 46 completes a circuit through contacts 62. v

The operation'ot the relay 46 resulting from The means above described for starting and Y The 40 movable contact of the relay 46 is operable to the momentary closing and opening 01' the load circuit l2, I3 sequentially operates a predetermined number of time element relays 53, 54, 55 and 56 through circuits which are completed through contacts 45 and 52 of the relay. These relays are the type having adjustable time delay opening characteristics. They are interconnected with one another through circuits completed by contacts which are closed in the open or closed positions of the relays and through contacts closed by the operation of the load circuit relay 46.

The operating circuit of relay 53 is completed through the following circuit: from one terminal 42 of the source of supply 42, 43 through conductor 44, contacts 45 of relay 46, conductor 51, contacts 58 closed when relay 54 is in its open position, conductor 58, operating coil 68 of relay 53 and conductor 48 to the other terminal 43 of the source of supply 42, 43. An operating circuit for relay 54 is completed as follows: from conductor 42 of the source of supply 42, 43 through conductor 44, contacts 52 of relay 46, conductor 6|, contacts 62 which are closed when relay 53 is closed,

conductors

63 and 64, the operating coil 65 of relay 54 and conductor 48 to the other conductor 43 of the source of supply 42, 43. The operating circuit for relay 55 is completed as follows: from one conductor 42 of the source of supply 42, 43 through conductor 44, contacts 45 of relay 46, conductor 51, contacts 66 closed when relay 54 is closed,

conductors

61, 68 and 68 through the operating coil 18 of relay 55 and conductor 48 to the other conductor 43 of the source of supply 42, 43. The operating circuit of the fourth relay 56 is completed through the following circuit: from one conductor 42 of the source of supply 42, 43, through conductor 44, contacts 52 of relay 46, conductor 6|, contacts 62 closed when relay 53 is closed, conductor 63, contacts 1| which are closed when relay 55 is closed, conductor 12, operatingcoil 13 of relay 56, and conductor 48 to the other conductor 43 of the source of supply 42, 43. When closed relay 56 is also energized through the following circuit: from one conductor 42 of the source of supply 42, 43 through conductor 44, contacts 45, of relay 46, conductor 51, contacts 66 of relay 54, closed when relay 54 is closed,

conductors

61, 68, contacts 14 which are closed when relay 56 is closed, holding coil 15 of relay 56 and conductor 48 to the other conductor 43 of the source ofsupply 42, 43,

The relays 53, 54, 55 and 56 under the control of load circuit relay 46 operate a voltage varying means for the generator l8 which means is driven by a motor 16 energized through either of two control circuits which are selected by the relay 56 in its open or closed positions. circuit is connected across the source 42, 43 through conductors 44, contacts 45 of relay 46, conductor 51, contacts 66 of relay-54 and conductor 61, contacts 11' closed when relay 53 is open, conductor 18, contacts 18 closed when relay 56 is open, conductor 88, limit switch 8|, conductor 82, motor 16 and conductor 83. The other control circuit is completed asfollows: through conductor 44, contacts 45 of relay 46, conductor 51, contacts 66 of relay 54,conductor61,contacts 11 of relay 53, conductor 18,contacts 84 closed when relay.56 is closed, conductor 85, limit switch 86,conductor'85',motor 16,- and conductor 83.

The operation of the motor 16 gradually varies the voltage of the generator |8 through the operation of a rheostat 81 and the operation of a tap changing switch 88. The rheostat 81 controls One control c the energization of a separately excited field E8 of the generator and the tap changing switch 88 controls the number of turns of its series field 88 which is connected in the load circuit |2, |3. When the motor 16 isenergized through one of the control circuits above described it rotates in one direction gradually increasing the excitation of the generator l8, and when it is energized through the other control circuit described above it rotates in the opposite direction gradually decreasing the energization of the generator l8. Themotor 16 is mechanically connected to the arm 8| of the rheostat 81 and to the operating element 82 of a Geneva movement, the other element 93 of which is attached to a rotating arm 84 movable over contacts 85 to which the several turns of the field 88 are respectively connected. Conductor I3 of the load circuit is electrically connected to arm 84 which also operates two limit switches 8| and 86.

With the parts in their position illustrated in the drawing, the generator I8 is fully excited, all of the turns of the series field being connected in the load circuit l2, l3 and the resistance of rheostat 81 being reduced to a minimum. Rotation of the motor 16 in a clockwise direction will decrease the excitation of the generator |8 by first decreasing the strength of its field 88 by gradually inserting the resistance of the rheostat 81 in circuit therewith and when the full resistance of the rheostat 81 has been inserted in circuit with the field 88 by operating the tap changing switch 88 to decrease the number of turns of the series field 88 connected in the load circuit. Rotation of the motor 16in the opposite direction will increase the excitation of the generator l8 in a reverse sequence. The time of operation of the motor 16 depends upon the timedifferential between the operation of the relays 53 and 54 and the direction of rotation of the motor 16 depends on which of its two control circuits is energized which in turn is determined by the position of the relay 56.

As has been pointed out above, the generator illustrated in the drawing is provided with a separately excited field 88 and a series field 88. The separately excited field 88 is connected across a source of supply 42, 43 and the field winding 88 is, as has been pointed out above, connected in series relation with the load circuit 2, Generators having difierent field arrangements may be employed without departing from my invention. When a source of separate excitation 43 is not readily available I prefer to employ a generator having the construction and circuit connections illustrated in Patent No. 1,340,004, Sven R. Bergman, granted May 11, 1920, in which case the circuit 42, 43 may be connected across the constant potential brushes of the generator and the system will consequently be self-contained.

As has been pointed out above, the system disclosed is a welding system and its operation will consequently be described in connection with a welding operation. The system is intended for use in those applications where the welding operator finds it necessary to perform a welding operation at a point remote from the welding set, and is intended to enable him to control at the point of welding the voltage adjustment of the int ber of times. At the same time the arrangement is such that unexpected arc interruptions during welding, or repeated attempts to strike a welding arc will in no way disturb the voltage adjustment when the welding set IO, N has been shut down due to the operator's failure to perform a welding operation for a predetermined .length of time.

To start the welding operation the operator touches the electrode M to the work i5. This completes a short circuit connection through the secondary of the transformer I6 which as has been pointed out comprises the load circuit l2, I3. The closure of the secondary circuit of the transformer l6 increases the flow of current in its primary circuit and causes the relay 22 to operate. The operation of relay 22 closes contacts 29 which establishes the operating circuit of the coil 21 of switch 25 as follows. From one conductor of the source of supply l8 through conductor 30, stop switch 3|,

conductors

32 and 33, contacts 29 of relay 22,

conductors

34 and 35, contacts 36 of relay 31, conductor 38, operating coil 21 of switch 25, and one of the conductors 26 to the source of supply l8. After the switch 25 is closed it completes a maintaining circuit through contacts 40 as follows: from one conductor of the source of supply l8 through conductor 3!), switch 3|,

conductors

32 and 33, contacts 40 of switch 25, conductor 35, contacts 36 of relay 31, conductor 38, operating coil 21 of switch 25, one of the conductors 26 to another conductor of the source of supply l8. The connection of the motor I to the source of supply |8 causes the same to operate the generator H] which soon builds up its voltage. The welding system is now operating so that the welding operatorcan initiate his welding operation. If, however, the operator fails to perform a welding operation after a predetermined length of time which depends upon the adjustment of relay 31 the welding set will shut down. Thus, as soon as the voltage of the generator [0 has built up to a value greater than the arcing voltage of the welding arc the relay 46 completes a circuit through contacts 45 which energizes the operating coil 4| of the relay 31. This circuit is completed as follows:-From conductor 42 of the source of supply 42, 43, through conductor 44, contacts 45 of relay 46, conductor 41, operating coil 4| of relay 31, and conductor 48 to the other conductor 43 of the source of supply. The energization of the relay 31 for a predetermined length of time causes the separation of the contacts 36 of this relay which'interrupts the circuit through operating coil 21 of switch 25, and this switch opens thus disconnecting the motor II from the source of supply It. I

If upon initiating a welding operation the operator decides that the voltage of the welding By twice touching the electrode= lays 53, 54, 55 and 56, through the circuits above traced. Relay 53 is energized through contacts 45 of relay 46 and relay 54 is energized through contacts 52 of relay 46 and contacts 62 of relay 53. Thereafter the closure of contacts 45 of'relay 46 energizes relay 55 through contacts 66 of relay 54 and the'second closure of contacts 52 of relay 46 energizes relay 56 through contacts 62 of relay 53 and contacts 1| of relay 55. Thereafter the second closure of contacts 45 completes through contacts 66 of relay 54 and contacts 14 of relay 56 the holding circuit of this relay. It is because of the time delay opening characteristics of these relays that such circuit connections are possible. The closure of relay 56 completes one of the control circuits of motor 16 as follows: from conductor 42 of the source of supply 42, 43, through conductor 44, contacts 45 of relay 46.,

conductor 51, contacts 66 of relay 54, conductor 83, to conductor 43. The motor 16 will then' operate to insert a portion or all of the resistance of the rh'eostat 81 and after all of the resistance of the rheostat has been inserted to operate the

Geneva movement

92, 93 to cut out a portion of the series winding 90 through the agency of the tap changing switch 88. This change is gradual depending upon the speed of operation of the motor 16 and continues for a period of time determined by the time differential of relays 53 and 54. Thus, if relay 53 is adjusted to release after one second, and relay 54 to release after two seconds, the motor 16 will be energized for one second. At the end of the two seconds period of time relay 54 will release opening the above traced control circuitat contacts 66. The opening of these contacts will also deenergize the holding coil 15 of the relay 56 allowing it to release to its open position.

If after having thus adjusted the voltage of the generator the operator desires to raise the voltage, this can be accomplished by momentarily closing the load circuit, i2, l3 by momentarily touching the electrode l4 to the work and thereafter separating it therefrom without striking an are. This procedure will cause the relay 46 to operate in such manner as to complete the energizing circuits of relays 53 and 54which in turn will complete the other control circuit of the control motor 16 through the following circuit: from conductor 42 of the source 42, 43, through conductor 44, contacts 45 of relay 46, conductor 51, contacts 66 of relay 54, conductor 61, contacts 11 of relay 53, conductor 18, contacts 19 of relay 56, conductor 80, limit switch 8|, conductor 82,

control motor 16 and conductor 83 to the other is one second. Thus, after the operator has touched his electrode momentarily to the work once or twice and thereafter holds it away from the work without striking a welding arc, the voltage varying means of the generator I0 is brought into operation for one second. If the operator does not withdraw his electrode from the work and wait for this predetermined length of time nothing will occur. Thus, in those cases where the operator has,.experienced anunexpected in terruption or the welding arc and immediately restrikes the arc and in those cases where one or more attempts are made to strike the arc terminating in the establishment of an arc the relay 6 will'close contacts 52 and open contacts 45 and remain in this position during the welding operation. The opening of contacts 45 will deenergize relay 53, and the opening of this relay will deenergize relay 54 so that all of the time element relays will be in their open positions a predetermined time after the welding arc has been established.

It will thus be seen that I provide a system in which the voltage of the welding set may be adjusted by the operator at his point of welding simply by touching his electrode a predetermined number of times to the work. Also, as has been pointed out above, the operator can start the set by touching his electrode to the work and, if weldingoperations are suspendedfor anyv length of time after the welding set is in operation, it will shut down .of its own accord.

In the arrangement shown in Fig. l a voltage responsive relay 46 has'been employed. Under some conditions of use it will be found desirable to use a current responsive relay 96, Fig. 2, whose operating coil 91 is connected across a shunt 88 connected in the load circuit l2, l3. The control circuits through the contacts 45 and 52 of this relay will be as illustrated above with the exception that the control circuits 51 and lil are reversed in view of the fact that in a current responsive system the relay 96 will be energized when the electrode H engages the work l5 and will be deenergized when the electrode is separated from the work without striking an arc.

The system above described may be variously modified without departing from my invention. It is, of course, apparent that various types of time element relays may be used, depending on the timing characteristics required. Thus in practice relay 3'! may be of the motor or clock type inorder to secure appreciable time delays. It is also apparent that instead of using relays 53, 54, 55 and 56 having time delay opening, relays having a time delay closing may be employed by suitably altering the control circuits as well as the time of operation of the relays to perform the functions above described. Various types of generators may be employed and characteristics other than the voltage thereof may be controlled by a system embodying the features of my invention. Thus, while I have described and illustrated two embodiments of my invention, it is to-be understood that other embodiments may be made without departing from the spirit and scope of my invention as defined in the claims annexed to and forming a part of this specification.

What I claim-as new and desire-to secure by Letters Patent of the United States, is:

1. A power system comprising a generator, a load circuit connected to said generator, means for gradually varying a characteristic of said generator, and time element means responsive to a predetermined number of momentary closures of said, load circuit for energizing said generator characteristic varying means for a predetermined length of time, said time element means including a plurality of interconnected time element relays and said predetermined length of time depending on the time differential of the operation of two of said time element relays.

2. A power system comprising a generator, 9.

7 load circuit connected to said generator, means for varying the voltage of said generator, means including relays having different time delay op-- erating characteristics for operating said voltage varying means a predetermined length of time corresponding to a time differential of said relays, and means responsive to predetermined numbers of momentary closures of said load circult for selectively energizing said voltage varying means to raise or lower the voltage of said generator.

3. A power system comprising a generator, a load circuit connected to said generator, means for varying the voltage of said generator, means including relays having different time delay operating characteristics for operating said voltage varying means a predetermined lengthm of time corresponding to a time differential of such relays, and means responsive to predetermined numbers of momentary closures of said load circuit for selectively energizing said voltage varying means to raise or lower the voltage of said generator, said 'means being effective only if said load circuit is maintained open for a predetermined period of time.

4. A power system comprising a generator, a load circuit connected to said generator, means for gradually varying the voltage of said generator, time element means responsive to a predetermined number of momentary closures of said load circuit for energizing said voltage varying means in one sense for a predetermined length of time, and time element means responsive to a differential number of momentary closures of said load circuit for energizing said voltage varying means in the opposite sense for a predetermined length of time, said time element means including a plurality of interconnected time element relays and said predetermined length of time depending on the time differential of the operation of two of said time element relays.

5. A power system comprising a. generator, 8. load circuit connected to said generator, a relay connected to said load circuit and operable to two positions one of which corresponds to open circuit conditions on said load circuit and the other of which corresponds to closed circuit conditions on said load circuit, means for varying the' voltage on said generator, four interconnected relays having time delay opening characteristics the operating circuit of the first of said time element relays being completed through contacts closed when the second of said relays is open and said load circuit relay is in its position corresponding to open circuit conditions on said load circuit, the operating circuit of the second of said time element relays being completed through contacts closed whenthe first of said time element relays is closed and said load circuit relay is in its position corresponding to closed circuit conditions on said loadcircuit, the operating circuit of the third of said time element relays being completed through contacts closed when the second of said time element relays is closed and said load circuit relay is in its position corresponding to open circuit conditions on said load circuit, and the operating circuit of the fourth of the said time element relays being completed through contacts closed when the first and third of said time element relays are closed and said load circuit relay is in its position corresponding to closed circuit conditions on said load circuit, means including the voltage of said generator, said circuits being clement relays being completed through contacts closed when the second of said relays is open and said load circuit relayis in its position corresponding to open circuit conditions on said load circuit, the operating circuit of the second of said time element relays being completed through contacts closed when the first of said time element relays is closed and said load circuit relay is in its position corresponding to closed circuit conditions on said load circuit, the operating circuit of the third of said time element relays being completed through contacts closed when the second of said time element relays is closed and said load circuit relay is in its position corresponding to open'circ-uit conditions on said load circuit, and the operating circuit of the fourth of the time element relays being completed through contacts closed when the first and third of said time element relays are closed and said load circuit relay is in its position corresponding to closed circuit conditions on said load circuit, and the holding circuit of the fourth of said time element relays being completed through contacts closed when said relay is closed, said second relay is closed,

and said load circuit relay is in its position corresponding to open circuit conditions on said load circuit, means including a circuit completed when said fourth time element relay is 'in its closed position for varying the voltage of said generator, and means including a circuit completed when said fourth time element relay is in its open position for oppositely varying the voltage of said generator, said circuits being completed through contacts closed when said first mentioned time element relay is open and said second time element is closed.

7. A power system comprising a source of supply, a load circuit connected to said source of supply and means including a plurality'of interconnected successively operated time element relays for varying a characteristic of said source in response to momentary closures of said load circuit, the extent of successive operation of said relays being responsive to and differing in accordance with the number of times said load circuit is momentarily closed,

8. A power system comprising a source of supply, a load circuit connected to said source 0! supply and means including a plurality of interconnected successively operated time element relays for varying a characteristic of said source in one sense in response toa predetermined extent of successive operation of said relays and in an opposite sense in response to a different predetermined extent of successive operation 01' said relays, the extent of successive operation of said relays being responsive to and differing in accordance with corresponding numbers of momentary closures of said load circuit.

' BENJAMIN w. JONES.