US877144A

US877144A - Synchronizing apparatus for alternators.

Info

Publication number: US877144A
Authority: US
Inventors: Max Vogelsang
Original assignee: Voigt and Haeffner AG
Current assignee: Voigt and Haeffner AG
Priority date: 1905-02-02
Filing date: 1905-02-02
Publication date: 1908-01-21
Anticipated expiration: 1925-01-21

Description

110.87%144. M PATENTED JAN. 21, 1908.

m. \IOGELSANG. a SYNGHRONIZING APPARATUS FOR ALTERNATORS.

APPLICATION PlLED PEB.2.1905

5 SHEETS-SHEET 1- Milllllll j No.1877.144. .1. PATENTED 331N121, 1908.

- M. vosmsmm,

SYNOHRGNIZING APPARATUS FOR ALTERNATORS.

APPLIOATIUH FILED 31333.2,1905.

5 SHEETS-SHEET 2.

@Mwa

. PATENTED JAN. .21, 1908. M. VGGELSANG. SYNGHRONIZING- APPARATUS FOR ALTERNATORS.

APPLIGATION FILED P11311905.

. 5 SHEETSSHEET 3.

m, mummy JAN. 21, 1908;

M. voamsmw,

swemomnm APPARATUS FOR ALTERNATORSIH APPLICATION TILED FEB. 2|19 05 6 SHBETB-BHBBT A.

Tlim'n g V U NITED strains Parana MAX YOGELSAXU, Oi" FRANK FORT-ON-THE-Mhlh, BOOKENHEIM, GERMANY, ASSIGNOR TO THE Specification of Letters Patent.

SELLSGHAFT, OF FRANKFORT-Ol -THE-MAIN,

'SYNCHRONIZING APPA ATUS FDR ALTERNATORS.

Patented Jan. 21, 1908. 1905. Serial N0x 243.897-

To all whom it may concern.-

Be it known that 1, MAX V OGELSANG, a subject of the German Emperor, residing and having my postoliice address at 50 Parkstrasse, Frankforton the Main, Bookenheim, Germany, have invented certain new and useful Improvements in Synchronizing Apparatus for Alternators, of which the following is a specification.

Alternating current machines of every description require to be synchronized before they may besafely connected in multiple with the distributing conductors. However, the operation of connecting the se veral alternators with the conductors requires careful attention and great caution for determining the proper moment at which they may be switched 0n,- as otherwise serious disturbances and injury to machines and electrical apparatuses might follow My invention relates to an apparatus, which is so arranged as to automatically connect in multiple the respective alternator with the distributing conductors at the proper moment and at the same time it permits the disconnection of the alternator at will from the system. As is well known, heavy shocks with'serious disturbances might follow the improper connection of an :tllcl'llzltUl, not only, in case the alternator is ex ccssively energized, but also in case it is insullicicm'ly energized.

The automatic apparatus according to my invention comprises a tension relay controlled by the tension of the respective alternato'r, a phase-indicator and a relay thereby controlled, a timing apparatus and a relay thereby controlh-id, a sychronizing circuit connecting the said three relays, a subsidiary relay controlled by the tension relay and n ormally closing the synchronizing circuit, a plurality of switches for connecting and dis connecting the respective alternator with the distributing conductors, a switching-on solenold in connection with the plurality of switches, a switch actuating circuit connccting the switching-on solenoid with the solenoid of the timing apparatus, a switching-oil solenoid for opening the switch actuating circuit, an indepei'ident source of electrical current, either direct or alternating, arranged for supplying the current to either the synchronizing circuit or the switch actuating circuit, and where so preferred also several safety devices. The tension relay is so arrangedfthat it'- permits the subsidiary relay to close the synchronizing circuit, the moment the tension of the alternator is approxinately equal to that of the distributin conductors, but it causes the subsidiary re ay to I open the synchronizing circuit, when the tension either decreases or increases beyond certain limits. The relay controlled by the phase indieator closes the synchronizing circuit the moment the phase of the alternator is equal to that in the distributing conductors, but this relay again opens the circuit on the phase varying. Thus there are two break-points in the synchronizing circuit, so that the latter can be closed only in case both the tension and the phase of the alternatin current produced by the alternator are equa to those of the current in the distributing conductors. Then the solenoid controlled by the timing apparatus will be energized, but it can connect the synchronizin circuit with the switch actuating circuit only after a time in correspondence 'with the frequency of the current in the distributing conductors. Should either the tension or the phase of the alternator meanwhile vary, the synchronizing circuit will be again opened, when the timing apparatus will stop. When both the tension and the phase remain correct and the synchronizing circuit remains closed, the so lenoid controlled by the timing apparatus will at last by a switch connect th e synchronizing circuit with the switch actuating circuit, when the switching-on solenoid will he energized for causing the plurality of switches to connect the alternator with the distributing comiuctors and for locking the several switches. lnnnediately afterwards the switching ofi' solenoid will be energized for again opening the switch actuating circuit. The above mentioned safety devices will be referred to later on.

l'will now proceed to fully describe my invention with reference to the accompanying drawings, in which the alternating current is assumed to be a three phase current.

l igurcs and 1 are diagrams of the three distributing conductors, an alternator already connected therewith, a secondalten nator and the automatic apparatus for connecting the latter with the distributing conductors, Fig. 2 is a vertical longitudinal section on an enlarged scale through the timing apparatus, the solenoid therewith connected being shown diagrammatically, Fig. 5 is a part of Fig. 1, showing the position of the three switches when connecting the second alternator with the distributing conductors,

Fig. 4 shows a modification of a part of Fig.

5 1 Fig. 5 is a modification of the diagram Q, l u shown in Fig. 1, Fig. 6 1s a part of the sain and Fig. 7 is a part of the same on an enlarged scaleand corresponds to Fig.

Similar characters of reference refer to 1 similar parts throughout the several views.

a, b and c in Fig. 1 denote the three di tributing conductors, m, t and c are conduotors, which already connect the iormer with the first alternator 1, a, b" and c are a 1) and 0 denote three and c the conductors 20 ably secured on a vertical rod 3 and insulated therefrom in any known manner.

T he rod 3 is mounted in

suitable guides

4 and 5 to move longitudinally and forms a part of an a mature 6 of the switching-on solenoid 7.

'5 switch 8 is shown as secured on the upper end of the rod 3 and is insulated therefrom. The rod 3 is provided with a notch49, Fig. 3, in which the upper end of the vertical. arm 10 of a bell-crank lever can engage,

when the 0 rod 3 occu ies its no ermost osition so 3 r that the three switches a, b

and a hear from below against their respective contact pieces and thereby connect the conductors a,

and c with w, b and 0" respectively.

At the 5' same time the upper switch 8 will bear against its two The bell-

crank contact pieces

12 and 13. lever 10, 11 is mounted to rock on a stationary pin 14 and its horizontal arm 11 is adapted to act upon the horizont 4Q arm 15 of another bell-crank lever. The la ter is mounted to rock on a stationary pin 17 and its vertical arm 16 is hooked at the lower end for snapping beneath the head 18 of vertical rod 19. A spring 45 draw the arm 16 from the head 18.

said rod 19 is longitudiuall guided in sui 20 tends to with- The able guides 21 and 22 and may be in one piece with the armature 23 of the switchingof'l solenoid. 24.

'A switch 25 is secured on.

the lower end ofthe rod 19 and insulated therefrom. In the uppermost position of the rod 19 shown at Fig. 1, this switch 25 bears against its closes the switch be referred to later on.

two contact pieces and thereby actuating circuit, which will Nhen the rod 3 of the switching-on solenoid 7 occupies its lowest position shown at Fig. 1, it brings tl bell-crank lever 10, 11 into the position shown, so that the hooked arm 16 of the other bell-crank lever snaps beneath the head 18 and thereby locks the switch 25 in its closed position.

beveled oil on its lower face, that on the a The hooked end 16 is so mature 23 being attracted by t e energized solenoid 24,.its head 18 is enabled. to rise and move aside the hooked end. while overcoming the tension of the spring 20.

An independent any known kind is disposed for supplying either direct'current r alternating current, which may be used for exciting the several alternators or for other purposes. This source of electricity 26 is shown as connected with the. synchronizing

circuit

27, 28, 29, 30, 31, 32, as, 34, 3.5 37, 3s, :39, in which a tension. relay T, subsidiary relay S and a phase indicator rel P are inserted. It will be observed that the synchronizing circuit referred to comprises two branches one of which, 33, 44, 86 and solenoid 48 contains the solenoid 18 of the subsidiary relay and is controlled by the tension. relay T while the other branch of the

synchonizing circuit

27, 28, 29, 30, 31 and includes the subsidiary relay S, the phase-indicating relay P, and the solenoid 58 controlling the switch actuating circuit and governed by the timing apparatus A.

The tension relay 'l may be of any known construction, the only condition being, that it may be controlled by the tension of the cur rent furnished by the alternator 2 to be'connected with the distributing conductors. In F 1 I have assumed the tension relay T to be a well-known differential relay, that is one with two solenoids i0 and il and a common armature 42. The one solenoid 40 is connected on the one hand by a line 43 with one branch (L of the distributing conductor a and on the other hand by a line 4 1 with one branch I) of the distributing conductor 1). Thereby the solenoid 40 is placed under the control of the tension in the distributing con ductors. The other solenoid 41 is connected on the one hand by a line '45 with the conductor a" and on the other hand by a line 46 with the conductor 5*. Thereby the solenoid 41. is placed under the control of the tension (if the alternator 2. T is so adjusted, that it balances the weight of the armature 42 and brings it into its middle position, so that the lever 34, to which it is linked, touches neither the upper contact 35, nor the lower contact 37. Tl-he subsidiary relay S is so arranged, that when its electromagnet 48 is not energized, its armature 50 is detached by a spring 49, so that its rear arm normally connects the lines 2-7 and-'28 of the synchronizing circuit. The p'nase indicater comprises an incandescent lamp 5 1; and an electromagnet 52, which are both -'connected in multiple on the one hand by a line.

source of electricity 26 of i The spring 47 of the rela'yratus A may be of any uppermost meshes with th the ratchet wheel 84.

light. This will be clear, when it is taken into consideration, that two conductors b an a are connected, two different resg ectively. is without current, the armaturc 55 normally detached by a spring 56, so that the lever 57 does n01; connect the

lines

28 and 2!) of the synchronizing circuit. The electromagnet 52 will ,be more or less energized by the circulating current according to the strength of the latter and he lever 57 w ith the armature 55 will oscillate in correspondence therewith. Only on the current attaining its maximum will the lever 57 touch its contact piece and thereby connect the lines 28 and '29.

In the synchronizing circuit is inserted a solenoid 58, the armature 59 of which is placed under the control of a timing apparatus A and arranged for closi g the switch actuating circuit in the following manner. The

armature 59 may be made in one piece with a vertical rod 60, which is longitudinally movable in two suitable guides 61 :.-1'l,(l 62, see Fig. 2. A switch 63 is secured on the lower end of the rod an In the position of the armature 59 the switch 63 will bear from below against both contact pieces 64 and 65 and thereby connect the two lines 71 and 72. The timing appaknown construction. In the drawings it is assumed to be a clockwork comprising two gear wheels 78 and 81, two

pinions

80 and 82, a fly 83, a ratchet S4 fastened on the shaft 79 of the gear wheel 78, a pinion loose on the shaft 78 and lever 87 rigidly connected with the pinion 85 and carrying a pawl 88. The upper part of the rod 60 is formed with a rack 86, which e pinion85. It will be evienr from an examination of Fig. 2, that on the solenoid 58 being energized it will attract its armature 59 and ress the rod 60 u pward. Thereby the cloc work will be ut into motion and the fly 83 permits the IOt 60 to move upwards only slowly, so that the switch 63 may touch the two contact pieces .certain time, which frequency of the current in the distributing conductors. The moment the current is broken from any cause, the solenoid 58 is no longer energized but dropsits armature'59, which is permitted by the pawl 88 moving in the opposite direction under the action of the weight of' the rod 66 and armature 59 and sliding over the teeth of Then the timing apparatus A will stop. ()l' course the timing apparatus A is preferably made adjustable in any known manner in accordance with the said frequency.

69, 7.6 and 76 denote ordinary switches.

e automatic apparatus described is opinsulated therefrom.

which correspond to 1 distributing conductors I) and (z I l l l hen the electromagnct 52 of the relay 1 i l l l contact pieces, "28 and 29 ol tl eratcd aslollows: 'lheiirst alternator l is assumed to be already councctml with the thrcc distributing conductors r1, 1/ and c by the three conductors a, 11, r. The lattcr arc shown as simple, but it will be understood, that the first alternator 1 may bc providcd with a similar systcm as the se ond altcrnator 2. The switch 65% is closcdfio coiillccl the parts 68 and 7] of thc switch actuating circuit, while the two

switches

76 and 76" rcmain opcn as shown. The upper solcnoid'ltl of the trnsion relay 'l is cncrgizcd by ihc current derived from thc distributing conductors s and I) by means ol il c circuit 43, 44, so that the armature is attracted upwards and causes the 34 io touch thc uppcr contact35. source of electricity 26 and circulating in the

circuit

27, 33, 34, 35, 36, 3.), 3], 32 will chergize thc clcctroniagnct 48, so that the latter attracts its armature 50 and thereby causes its rear arm to break the connection between the lines 27 and 2S ol the synchronizing cir' cuit.

. On the second alternator 2 starting, it, will produce a current, a part of which circulates in the circuit 45, 46 and energizes thelower solcnoid 4] of the tension relay 'l .Thc moment the tension of this current is equal to that in the upper solenoid 40, the armature 42 will be brought into its middle position shown at Fig. 1, so that the levcrS does not touch either the upper contact 35 or the lower contact 37. Then the electromagnet 48 of the subsidiary relay S will be without current, so that the spring 49 detaches the armature 50 and causes its rear arm to connect the

lines

27 and 2%; of the synchronizing circuit. Meanwhile another part of the current from the alternator 2 will pass over to the distributing conductor 7) through the phase indicator circuit 54, 53, 4-4. If, in which both the incandescent lamp 5] and the elcctromagnet 52 act as resistances. The eleciromagnet 52 being thereby energized will more or less attract its armature 55, which will oscillate. When the lever 57 touches its it thereby connects the lines is synchronizing circuit. At the same time the incamlescent lamp 5] will give a light and indicate to the machinist the condition of the system. '

lhc synchronizing circuit

27, 28, 29, 230, 3], 32 being now closcd, the solenoid 58 or the timing apparatus A will be energized and attract its armature 60 upwards. 'lhercby the clockwork is put into motion, so that the switch 63 slowly rises and approaches to the contacts 64- :.nd 65. As is well known, the frequency of the alternator 2 may not always be at once equal to that in the distributing conductors (.L, b and 1:, so that the current circulating may soon decrease and the spring 56 will overcomethe attraction of the electromagnet 52 and detach its armature 55, whereby the syn- Then a current supplied by the chronizing circu t is again opened. The strength of the current circulating in the circuit 54, 53, 44, b may repeatedly increase and decrease and the armature will keep oscillating. Also the tension of the aiterna tor 2 may increase beyond that of the distributing conductors a, b, and 0, so that the lower solenoid 41 will be able to move the common armature 42 downwards andcause the lever 34 to touch theylower contact 37', when in a similar manner as described above the electromagnet 48 of the subsidiaryrelay 1 S will be energized to attract its armature 50 and thereby to open the synchronizing circuit. Thus the latter can never be closed, it the tension of the alternator 2 is higher or lower than that in the distributing conductors (1,, b and c. tance, as all shocks and injury'to machines and apparatuses are thereby avoid ed, When both the tension and the frequency of the alternator 2 become equal to those of the dis tributin conductors (L, b and c, the timing apparatus A will be put into motion fora sufficient time to enable the switch 63 to touch its contact pieces 64 and Giraud to connect the lines 71 and 72. Thereby the

switch actuating circuit

27, 6G, 67, 25, 68, 69, 71, 63, 72, 30, 31, 32 will be closed, so that the switching-on solenoid 7 is energized and attracts the vertical rod 3 upwards and causes the three switches a 1) and c to touch their respective contact pieces and thereby to connect the alternator 2 with the distributing conductors a, band 0. At the same time the upper end of the vertical arm 10 of the bellcrank lever 10, 11 will engage in the notch 9 of the rod 3 and thus lock the three switches a b and 0 The dropping arm 11 of the bell-crank 10, i1 releases by means of the spring-pressed bell-crank lever .15, 16 the head 18 of the rod 19. whereupon with the armature 23 the switch 25 falls and opens the switch actuating circuit. The upper SM .tch 8 on the rod 3 touches its two

contact pieces

12 and 13 and thereby connects the

lines

73 and 74.

If it is desired at any time to disconnect t e alternator 2 from the distributing conuctors a, b and c, the switch 7 6 is switched on: to connect the parts 7 5 and 77 of the switch actuating circuit. supplied from the source of electricity 26 and circulating in the switch actuating'circuih27,

-66, 73, 13, s12, 74, 75, 76,77, 32-will ener gize the switching-oil solenoid 24, so that it attracts its armature 23 upwards. The head 18 of the rod 19 will reach its uppermost position and strike against the horizontal arm 11 of the bell-crank lever 10, 11, so that the vertical arm 10 withdraws from the notch 9, whereupon the rod 3 with the armature 6 and the three switches a, 7) and 0 drops to disconnect the alternator 2 from the distributing conductors a, b and c.

This is of special nnpon' Then the current switches 69 When it is desired to connect the alternator 2 with thedistributing conductors a, l) and c, in case no current is in the latter, the switch 7 6 is switched on, while the other two and 76 remain switched off. electricity 26 will circulate in the

switch actuating circuit

27, 66, 67, 25, 68, 76 76 77, 32 and energize the switching-on solenoid 7, so that it attracts its armature 6 upwards and causes the three switches (1 b and c to touch their respective contact pieces. There,-

upon the rod 3 is locked by the arm 10 engaging in its notch 9 and immediately afterwards the switching-(iii solenoid 24 is energized for opening the switch actuating circuit in the 1 manner described above.

Where so referred, the tension relay T may be simp ified as is shown at Fig. 4, in which case the upper solenoid 40 of Fig. 1 and the circuit 43, 44 are omitted. Then the spring 47 is so adjusted, that normally it presses the lever 34 upwards against the upper contact 35 with such a force, that only on the tension of the alternator 2 becoming.

,equal to that of the distributing conductors a, b, and c, the solenoid 41 willbe sutliciently energized to detach the lever 34 from the upper contact 35 and to bring it into its middle position shown. Otherwise the operation of the automatic apparatus remains substantially the same before.

1n the system shown at Fig. 5 the conductors a b and c are ronnectedwith the distributing conductors much in the same manner as in Fig. 1. The conductors (1 b and c are also connected with the respective alternator. The three switches (i b and c are secured on the vertical rod 89 and insulated therefrom. The latter is shown only diagrammatic, but it may be constructed in the same manner as the rod 3 in Fig. 1 described above. The rod 89 is connected with the armature 90 and the upper switch 93 and provided with the notch 92. The bell-crank lever 94, 95 rocking on the stationary pin 96 and the other spring-pressed bell-crank lever 97 08 rocking on the stationary pin 99 are substantially the

same HS lGVGIS

10, 11 and 15, 16 in Fig. 1. In this modified system is a tension relay T, a phase-indicator relay 1 a timing apparatus A and a subsidiary relay S and other apparatus as will appear hereinafter.

sp'ective primaries 100 and 193 respectively connected by conductors 101, 102, with the conductors c" and b respectively which are connected with the alternator 1, and by the conductors 104 and 105 with the conductors a and I), connected with the alternator 2. The secondaries 106 and 107- are connected in a closed circuit by the lines 108 and 109, in

The tension relay T is constructed the latter of which a lamp L is inserted.

. 7O Then the current supplied from the source of sumac differential relay and comprises two solenoids 110 and 111, whose armatures are suspended froma horizontal balance 112 which is rigidly connected with a suspending contact lever 113. The solenoid 110 is connected across the terminals of the secondary 106, while the coil 111 is connected across the terminals of the secondary 107. It will now be a parent that the voltage impressed upon ,t 1e coil 1 10 will be equal to the voltage of the terminals or the secondary 108, while the voltags impressed upon the coil 11 1 is that at the terminals of the secondary 107. As tho/voltages of these secondaries are proportional on the one hand to that of the machine to be JOHIIBClS'dLl and on the otherliand to that of the system to whichit is to be connected, it will be apparent that the energizin of the coils 110 and 111 will be canal and t e lever 113 will be vertical when t .e voltage of the machine to be connected and that of the system to which it is to be connected are the same.

, It follows that if one voltage is greater than ,I so

- tial across the lam the other contact to one side or the other according to which voltage is the greater. If that of the machine to be connected is greater the lever will be thrown to the right and will'colne in contact with the contact 114. If the voltage of the system to which the machine is to be connected is greater the lever will be thrown towaros the left and willcome against contact 115. Thecontact 114 is connected through the lamp L and conductor 116 with the conductor 120 while the contact 115 is connected through the conductor 117 and the lamp L with the conductor 120. The coil 119 01" the subsidiary relay is connected on one side to the conductor 120 and on the other side to the conductor 121 which is connected with the solenoid 144 by conductor The conductor 125, in which is inserted the lamp L", is connected through the conductor 125 to the subsidiary relay contact lever 128. The conductor 125 is also connectcd to the conductor 131, while conductor 126 is connected through the

conductor

131 and 132 to one contact of the relay P. The phase indicator relay P is connected across the lamp 1; in the secondary circuit of the transformers by means of the conductors l37 and 138. it will thus ap ear that the voltage impressed upon the so enoid is equal to the drop in poten- L. The contact lever 133 of the phase int icator relay is connected by means of a conductor139 with the one terminal of the solenoid 149 which actua toe the plunger 141 controlling the switch element 1501c connect

thcconductors

149 and 151, the said plunger being controlled in its movement under the action or" its solenoid, by of the timing apparatus A. The ot r rminal of the solenoid 140 is connect l hrough

conductors

142, 143, 1222, low

lever 113will be deflected w th the other terminal of the electric source (co rresponding to source 26 of Fig. 1) to which the conductor d is connected. From the conductor 122 circuit passes through the solenoid 144, the solenoids 144 and 145 being differential and acting upon he same pluner 148, thence through conductor 152, so-

lbnoid 157 having armature 158 which is adapted to connect conductor 159 with one terminal of the solenoid 157, thence through conductor 156 and switch 155 to the switching on solenoid 91. c

t will now appear that, when the relays S and P are closed that the solenoid 140 will be energized through a circuit as follows: From the conductor d through conductor 180, contact piece 129, lever 128,

conductors

126, 131 and 132, lever 133, conductor 139,

solenoid 140,

conductors

142, 143 and 122, high-resistance solenoid 144, conductor 152, solenoid 157, conductor 1'56, switch 155 and conductor 154, to one terminalol the switchon solenoid 91, the other terminal" of that solenoid being connected to the conductor e. The solenoid 144 being thus energized the armature 148 will be attracted and the switch 147 will be closed. Thus far the solenoid 91 has not been energized owing to theiact that the high-resistance coil 144 is in series with it. The solenoid 140 however,

emg energized, after a certain time has elapsed, depending upon the adjustment of the timing apparatus A, causes the switch 150 to connect the conductors l49 and 151, thereby sho'rt-circuiting the high-resistance coil 144 through conductors 122 143, 142, 149 and 15 1. Circuit is then made from the conductor at through conductors 124 and 123, switch 147, conductor 146, low-resistance solenoid 145,

conductors

122, 143, 142 and 149, switch 150 and conductor 151 to the conductor 15; whence circuit passes through the solenoid 91 to the conductor e as before traced. The high-resistance solenoid having thus been removed from the circuit of the solenoid 91, sufficient current flows to ener gize that solenoid whereby it operates to connect in the machine in a manner as de-' scribed in connection with the previous figures. The whole current for energizing the sblenoid 91 passes through the low-resistence solenoid 145 and serves to maintain the switch member 147 in closed position after the solenoid 144 has been short-cm cuited. Upon the breaking of the circuit at the switch 155 after the connecting operation has been performed in a manner as described in connection withpreceding fig ures, the solenoid 145 becomes denergin'ed and the switch member 147 opens. It now becomes necessary that synchronous conditil tions shall be again reached before the solenoid 91 can be again energized to effect a connecting operation, so that it, after synchronization has been reached and the machine connected, to the system, it is necessary to disconnect the machine because of short-circuit or otherwise, it will be impossible to again conne't in the machine by reason of the setting of the apparatus due to the synchronous conditions existing at the former connection, but it will be necessary to again reach synchronous conditions before connection between the system and machine can be effected.

When the high-resistance solenoid 1 14 has been short-circuit'ed asdescribed and sulficient current to energize the switching-on solenoid 91 passes through the solenoid 157 the last mentioned solehoid will become en-- er ized, and attracting its. armature 158, will connect together the

conductors

159 and 152, thus providing a connection in addition to the switch 150, whereby-the high-resistance solenoid is short-circuited. This is for the purpose of maintaining the operative cir cuit of the solenoid '91 c. osed after it has once been closed by the switch 1.50 until the connect-ing operation has been completed. It would be undesirable for the operation of-the connecting means to be arrested before completion, after it had once been started. It will be seen that this undesirable occurrence is avoided by the use oi the solenoid 157 which is supplied with current through its own armature and therefore remains energized until its circuit broken at the switch 155 upon. the completion of the connecting operation. Without the use of this solenoid 157 the switch 150 might be only momentarily in engagement with its cot'iperatiug contacts as, after coming intothe position indicated, the conditions of synchronism might be slightly varied from, whereby the switch 150 would leave its contact and the connecting operation which had been begun would be arrested. 'With the use of th s solenoid however, the operation of connecting, after once having been started by the attainment of synchronous conditions, is carried to completion.

It has been observed that in order for connections to be established as just described that the contacts of the phase-imlicator relay P and those of the subsidiary relay S must be simultaneously closed. This can only occur when the voltages oi the apparatus to be connected and the conductors to which connection is to be made are at the same voltage, and also they must be in base. Itwill be obvious that thegreatest tall of potential across the lamp L will occur when there is coincidence in the phases of the voltages in the conducc 7) and a, N, and the spring 13 is; rig Listed that the armm ture 133 will come in contact with the terminal of the conductor 132 only when there is this maximum fall of potential across th lamp L and therefore the application of a maximum potential to the solenoid 136.

The lever 128 of the subsidiary relay S can only come against its contact 129 when the solenoid 119 is denergized. This can only occur when the contact lever 113 is not in engagement with either of the contacts 114 and 115 for, if the lever engages with either of the contacts referred to, circuit may be traced from the conductor (1 through the conductor 118 lever 113, conductor 120, solenoid 119, and

conductors

121 and 122, to the high-resistance so old. 141, whence circuit may be traced through the solenoid 91 to the concuctor e. As before pointed out, if the voltage of the lines a and b*, is too small, the lever 413 will come against the contact 115 so that connection is made with the conductor 120 through the lamp lfand the burning of this lamp will indicate that the voltage of these lines is too small. Ii, on the other hand the too high, connection with the conductor 120 will be made through the lamp L and the burning of this lamp will indicate this condition of the voltage. hen, however, the voltage of the machine to be connected and the distributing conductors are equal and,

with either of the contacts ll and 115, the solenoid 119 will be deinergized and the lever 128 will come in contact with the contact piece 120. This contacting of the lever and. cont-act piece not only serves to close the synchrimizing circuit at this point but it also closes a circuit through the lamp L which may be traced as follows: From the conductor (1'- through conductor 130 contact piece 129, lever 128, conductor 126, conductor 125 containing the lamp L, conductor 121 and conductor 1'22 to the high-resistance solenoid 144 whence circuit may be traced as hereinbefore through the solenoid 91 to the conductor e. The lamp L will then be lighted and aiiord an indication of the fact that the voltages of the lines to be connected together are equal.

The switches 1th) and 161 correspond to those 76 and 7 6 respectively in Fig. 1. The operation of the auto matic apparatus shown at Fig. 5 is otherwisesimilar to that of the apparatus shown at Fig) 1.

The automatic apt aratus may be varied in many respects without deviating from the spirit of my invention. In some cases the regulator for exciting the alternator may be provided with adjustable contact pieces on that place, whichcorresponds to the correct tension, and those contact pieces may be connected with the tension relay T for controlling the same.

voltage of these lines is,

therefore, the lever 113 is not in engagement "Wht I claim a my invention, to secure by Letters Patent, is-

The coinbinctionwith an alternating c rrent machine and its distributing conductors, of second siternating current ins chin-o, connections between said conductors and said second alternator provided with and desire switches, tension relay controlied by the tension in said alternator-s, a phase indicator, a solenoid with a. timing apparatus, a synchronizing circuit containing said solenoid and adapted to hc'closcd by suid tension roiuy on thcrc being the correct tension and. by said i .so indicator on there being tho corroct phase, and a switch. actuating circuit adapted to he closed by said solenoid on there being the correct frequency and to close the switches in said connections.

2. Tho combination with the distributing conductors of an alternating current mschinc, of second alternating current n1achins, connections between said conductors sud said. second alternator provided with switches, at tension relay controlied by the tension in said siternntors, a phase indicator, o solenoid with a timing apparatus, a synchroni cg circuit containing so id solenoid and adapted to be closed by said tension reicy on there hcing the correcttension and by said phase indicator on there being the correct phase, a switch actuating circuit adapted.

to he closed by said solenoid on there being the correct frequency cnundapted to close the switches in said connections, and means for locking the switches and afterwards 0 peniug said switch actuating circuit.

3. The combination with current conveying distributing conductors, of an alternating current machine, connections between them pro'vidcd with switches, a tension relay controlled by the tension in said 'crnctor, a subsidiary relay controlled h and tension rein-y, a phase iudicsitor, ft reis v controlled by said phase indicator, scieuoid with a timing apparatus, ynchrcnizing circuit containing said solenoid and adopted he closed by said subsidiary rehi'y and said reiuy, a switch actuating circuit sdsptsd to he closed by said. solenoid and to close tho switches in said connections, and means locking these switches and afterwards open-- ing said switch actuating circuit.

4. Tho combination with Iii-sin. current conveying distributing conductors, of an. oitornu-ting current machine, tween them provided xvi switches, on dependent source of electrical current with two distributing conductors, a tension relay coin trolled by thetension in said alternator, a subsidiary relay controlicd by said tension relay, a phase indicator, a relay controlled by said phase indicator, a solenoid with a time apparatus, a synchronizing circuit joined to said two distributing conductors and containing said solenoid and -sdopted to he closed by said subsidiary relay and said 1' my, a switch actuating circuit joined to said synchronizing circuit and adapted to he closed by said solenoid and to close the switci es in said connections, sud means for locking these switches and afterwards open ing said switch actuating circuit.

In testimony Whereot I have name to this specification in the two subscribing Witnesses.

. MAX VOGELSANG.

signed my presence. of

Witnesses:

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