BEST AVAILABLE COP'@, 1,633;938 tlie s@illie ti,iie,. coiyipletes a. circuit for the closin(r coil 63 of circuit iiiterrupter 53 and the Ii'ttei- (-loses t,,,) coniplete the running coniiectlons of the motor. Tl@e line circuit breali:er 66 is. tlien closed .it tiny (lesire(i tinie either inaiiually or by .iiiv otlier suitable and NNell-known means, t]iL@ (lettils of suo@i ilie-,iiis cons'Lituting no I)-ii-t of tli(-- I)reseiit invention. Tli@,- operitioii of tbe- systeiii iii-.iy be disiil)oii the ocetirreiic(- of any deI In ictu-,tl pi .qlreil (-(%iid'tion. -actice, autoili.itic iiie;-.-is ai-e cilliplo3,ed to effect the openiii,r of the coi)ti-ol cii-eiiits in accordance witli .'5 ()I)el,,ttin,-,(-oii(litions. Siiclili-ieans,lio-%vever, t-oll@;titllte, 1-0 pai-t of the preseiit invention ftnd I li-.tvt! accordin(,Iy illitstrated only t iii.intially-ol)er-.ible switeli 65 -%vhichl upon (:Io,;in,,, coti)l)letes .1. cii-cuit for tl.'ie tripping 20 (,oil (54 of cli-eiiit iiitei-rtil)tei- 53. Tlle. circuit iiitei-riipter 53 opeiis to di,@connect the inotor 4.6 fi-oin the line. Wben the volti(ye of the exci -eicreiiei-,itoi? 47 fal:ls to -,t predetermine(I v,iltie, tlie. coil 17 of loelcolit switeli 1-6 is (leeliel.(Yize(l to Pei-lylit the opeii:ino,, of tlie swit(!Il IC). The loiv-volta(re reltv 30 open,; lo effect the openin- of tr-.insfei- i-elay 55 .Lnd the svsteiii is in re-,idiness f@)r the succeediii- stai-tli@n,- operation. zi@eference iiity ii. now be lin(I to Fi-. 37 ivliieli :t svsl-eiii soiiiewliat siiiiilar to that of Fi- 2 is illii,,;ti-ated. The e-,;se-iitial difrerence between the -above-iiientioned ystems is tli.at the -,tiixiliai-y i-elal, .30 an4. t-be transfil-r relay 55 of the s3--qteni ;f Fi-. 2 ii-e oiiiitfed froin the sv,,@tem of Fi- 3. The. lockout switeb 16 effects the operatioii of the se-%,era-I circuit iiitei-i-tipte.rs (lire@--tly instead of' indiree-tly tlirou(rli i-elays. The svsteii-i is started as in tbe. gystem of Fil-1. 2 bv the closing eitlier of the iclay 59 or of t-lie niani-iallv-ope-rable si@iteli 61. VNben the motor li-,ts"accelerated to substaiiti.illy .c@ynebi-onotis speed, the loelcotit siviteli -15 16 eloses 'm the iyianner pietrioiisly described., The contict iiieiiibeis 23 and 25 complete t eireiiit -%Yliieli exten@ls froni coiidiie-tor 67 tl.iroti.4c,rli coiitict iiieiiibei-s 23 and 25, s,%vitcli 71, trippini2: (-oil 58 of eireiiit interriiptei-s 51 -4iii(I 59-, ;@'ferloelc '12, ,ind condtictors 73 to condtictors 69. The cireiiit iiiterrtiptei@s 51 -ind 5'-' iccoi-diii,-Iy open. A (-irt-iiit is also completed by contact -?'a ind 2r) @",hicli extends -througli ,@5 coil 63 of eireiiit interruptei53 aiid ,-oiiciiietor i3 to coiidiietor 69. The circuit iitei-riipteir)3 closes to coiiiplete tlie noriii-,il cii-eiiit of the iilotor. The closiii!_y of sin-iteli 16 effects, -,tlso, the t;il en(,riLre-nient @f contlict iiieiiil)ei-s @4 -ind 26 to (-oniplete tlie field eireiiit of the motor 46 iylii(,-Ii exteiicls fro-ni oiie tei-iiiiiial of the ex(,itei- -eperitoi, 47, tlirou(yli field-ina,- -ii-et win,,Iinir 54 i.iid coiitict iiie-i-iibers 26 and 24 to the (@flier teriniiizil of the exciter -eneratoi-. To briii(r the sys'..@iii to i-est, tlle switell 6.5 -@ s to its clo,@e(I positioii. to coiiil)IL@te it eireiiit for the c-oil G4 of eirctiit interrttpter 53. The eircitit IlItUl'I'LIl)ter 53 ol)eiis ziii(I tle variotis ciieiiits ;ire (le- 70 eiierfrizell is de!@eribed 'ii coiiiiecti(;ii ith s 1_. . The opciiill(,. of Cil-CLtit the ysteiii of Y',r 2 L iiitei-i-i.il)t,,i-s 5.1 52 dtirin(r 'lie - @3LartiD" oper.Lti4iii bL Lceo.,iit)lislic(t bv itte ictiittioii of switelt to it.-@ l(iwer posili(iii to cojii- 7.5 ])Iete a cii-eii:.t 'L 1,, r tiiv (,o'l 58. It its ;s tliztt tiic snv'tc'ii ---I oc(-i@ipy illtisirtt-.e(I I)o--,Itioji iii (;rt'ler (-Ii:tt the locicotit s%viteli iiit Li . (,@llet-t the froiii Stlutiii,r coiiiiectlojis to It will be liotet! I'I!Ztt by it of tile -11-- tljove (tes(;ril)eti, I Lill to eff(!et II)e tcce',erittloii of L syneiii-oiioti-@: liiot(,c Slibst:tiiL'-,:Llly notis sl)eetl z,,iitt io c:@itl)lis's) iiociiiztl ope,-atii)g coil(litioii,; -foi- ti.-e iiiotoi-. The provisioii of tii tl,.e -,irriii(re-iiieilli :oiijl)letes ;I lioidwh(, iii,,- eiriiiit f(,@i- it-,, t-oll iiiqtires tl@,,-,t ttie of the iiiotor ire iiot OI)CIIEL[ 'Ipoti t-ii(! oc@-tir@-z@itce of zibiioviii4-LI coiiclitioiis iii tiie tie'-Zd cli-etilt of tli(@ iiiotoi-. Bv c-.tl-il)ratiii!-, tiie, relay tt) -.tny (lesii-e(I -Ytltte of tlie. fil@ld ctit-rent, the closin@@ of the riiiiiiiii,, cot.,iie(,-tioiis iiiztv be defel-red tl iititil- the ficici etti-t-(@iit :Ls of -.tiiv de,@;ired villie. 11. will be if ftill N-olti-C is it)pl-ie(.1 t-o tl-j(,@ iiiotot- Nvlivii the 1-itter is un(ler lie:tv@y 10,tL[ ',III(] the -.Lielki-itizity-iiet wiiic'linty, is enei--izet.1 I)v (-iii-i-ent o-l' i?elitli?elv lo%v v-.111[e, tile illil(.or tiot III SN'llelii-onisiii. tfiicier siif,-Ii iiecessai-v to (-lie. ol.)(@i-zitioll. It ivill ]3e iiij.,)ossil)lc to effe(:t tfi-e colitilitle(I opei-at-ioii of tlit@ iiiotor tintlt.i- ;iieli (-ii-ciinis6iiiet-s unle-,s tlie coriditioiis ii-e 1 claim as inv liiveiiti(ii 1. In a iiiofi)r stiii-tei-. the coi-nl)liiitioii witb L s3,neiii-oiinit,@ inotor liivin- -.i fi(@ldnia(ynet vvitiflin(,, st:ii-tin(Y primary coi)neetiolis foi- illotol., of ii-ieans controlled iyi witli the. %,aliie of the ciii-i-ent s:t.i(,l %viiifliii(- dui-iiig the stai-tiii4r oi)t!i-,it-ioii foi- i-eii(lei-iii,, stiid stai-tiil,, conlie(-tioiic; illefrc(-( :111(l @:iicl ruiiiiiii- connectioiis effe(-tive, '111(i foi- I)i-e-ntiti-, V(, ti cliaii(,e iii sal(i coniiectioiis iil)oii tlie,oceiii-rence of -.iii iii(Iii(-tix-t@ iii ,3aid windiii-,Iftei- the i-iinniiia (-niiiiectio-ns liive been coii)l)leto(.1. 2. In a iiiotor stzii-tei-, tlie. 1011 -witli i sviicliroiioiis iiiotoilii-N-inrr I ficl,]n-ilt(,-Iiet - %vindiii-, -,in(-l pi-iinii-v cojiiie(-tioiiq foi- s;i i(', iiicitoi-. of conti-olle(l in -iccoi-(Iiiiec )vltli tile' x-,Iliic of the ciii-i-ent iviii(lin,--, (Iiii-in,, the sti.rtizi,- opei--itioyi foi- i-en(lei-iii-atst-,trtin(r coniiections ineffecti-,-e iiicl s;il(l rtinnin- coniiectioiis; effective Iii(I foiI)re.130 -,-entliiLr t (- Ii;in!@e 'ji sii(i coiiiiect'oii(3 iil)ou

1,633,938 tl-ie occurrence of aii inductive disturbance ii,i said winding after the running conneet]ods have been coinpleted, said means comprising a circuit-controlling device, actuating and holding nieans tberefor a-nd a relay for controlling said actuating means. 3. In a motor starter, the combination i-%,ith a synchronous motor having a fieldn-iao,met -windiiig, and starting a iid running 10 primary connections for said motor, of means controlled in accordance witli the -value of the current traiisversing said windduring the startino- operation for renin (le@ li g said startin- connections ineffective 15 and said running connections e:ffective and for preventing a change in said connections tipon the occurrence of an inductive disturbance in said windiig after the running connectiods have been completed, s,,tid means 20 coiiiprisina a eircuit-conti@olling device, acttiatincr and holdin- me'ans therefor and a relay havino; an ictuating coil in circuit iv,ith said field-nia,-net -winding. 4. In a motor starter, the combination 25 with a syiiehronous motor having a fieldniagnet winding, of means for automatically BEST AVAILABLE COP'. coiiti-olliiig t,he starting ;iiid the rtirinina coiiiiections for said motor in accorda-nee-witli the value of the alternating current traversing said windin(y durin(r startin(r, a relay for so effecting a transfer in said connections, said nieans comprising a holdiing circuit for said rel,,ty, actuating means for said rel-,Iy, and a, relay baving an actuating coil in circuit with said winding for controlling the actuating 35 meaiis of the first-nam-ed relay. 5. In a motor starter, the combid,,ition -witli @i synchronotis motor bavirl(r a fieldmd.,-net windina and starting an d runnin,primary connections for said motor, of 40 means for automatically effectin(y the estabel lishinu of sta,rting connections, and means COD, ipi@isino- a loclcout switch and a plurality of success@ively opei-@ible relays for ttitomatically e:ffectin(y the transition from startin 45 9 connections t@ running connectiojis when the current trtversing said field-magnet windinZD reaclies a predetermined value. In testimody -%vhereof, I have hereunto subscribed my name this 21st day of July, 1920. WALTER C. GOODWIN.

Patented June 28, 1927. BEST AVA-ILABLE COP@ @6332938 UNITED 'STATES PATENT 'OFFICE. WALTER C. GOODWIN, OF PITTSBURGH, 3?ENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTUP.ING COMPAITY, A CORPORATION OF :PENNSYLVANIA. S-INCIEERONOUS-NOTOR STARTER. Application filed July 30,1920. Serial No. 400,141. . I . to siiiiiiltalleolisly effect the establisliin,, of Gr>- rtiniiii),q eolliiectiolis for the i)lotor by me-,Ii)S of a locl.:oiit s-%Yiteli. The locl@out switch is provided -%Yitli ',I C109iDg COil wh'cli ilifty be in circuit witli tlle (,@-xciter or otlier source of ellcl'- ln(I a locl@out c@)il that 's - in sei-i" 60 rY ivitli the fielcl iii-q@rnet Aviiidina of the motor. The loelkout coil, wliich is ener-ized by "Iltel-natila- cultent of substantially@'const,,tnt value uiitil@tlie conditioii of sylieliron'sn-i ' is re,,,ched, retaiiis the controllin(y s-%vitch in its <)pen positioii until the motor has i-eaclied synchronism. The current traversi.D,(,)' the field circuit then falls to substantially zer . o value. and the switch closes to connect the source o-f excitin,,- current to the field-ma,,-net 7i) windinc,, aiid to establisli runnino, connections for the motor. t@ According to the present invention ' ) I: provide an auxiliar sNvitch.for controlling the y circuit of the eneroizino, coil of the tran f s er 7r) relay for effectin@- the @ha,nge from startilig connections to ru-nni-ng coiiiaections for the niotor... The transfer reliy in closing com@ pletes a holdin(y - circuit for its. actuatin,r-. coil ' -The transfer relay remains closed and' 80 is not affected by the ppsit i o A o f t h e a u x : . - @ y n e b r o n i s m b o n - o f - t h e : i e a s 6 d . i , i l i a r y @ r e l a ; y , i n @ c a s e t h e l a t t e r o p e n s u p o n t h e y reas ner o -runnino,:con ons The -@;peed Om f of@ the, rnoto 1-This'deerbase i ,c -- @.i@stablishin,,,., necti 3o pen atecl: for by! the decrease.-i-h ieactance be- opei3ing , of the aiixili ary relay. m @y - occur. cause of the'lowei fre4uen4 of the field curunder such, conclitions by reaso]3-@of t@e'fa.ct@'@8'5 rent' Acco@di@'@,l@i th-e decrea@e in@the -elee- that its actuating coil is connected -to ihe ex+roiiiotive force a citer circuit and is therefore in circuit witli does not operatd- to cause . 2 5 :corresponding decri@a . se - in the value of the the. field-magnet windincr Inductive - dis35: ciirre'nt a-nd th6 latter, iemains substantially - turbances in the - -fibld circuit accordingly as set fortb abov6.' aiffect @be operation of the aiixiliary relay 90 It ba's been found, alsc;, that,' when the :only. riinnid-'connections are establisbed to - apply In.the .iccoinpanying 'rawino's noriyia. -he prii 1 is, a diaoram volta-@e to t -n-,iry @ivinding of matic viev@:of. cirz@, Figure 40 the nioior' therelisl-.in'duced in tb'e field eir- Cnits in apparatus e@-nbodying niy invention. ellit -,i. Wl"vc of electroinotive force of sucli ; -Fio,,s. 2 and 3 are similar views illu'stratin(,- 95 -tmp] itiide as to effect the openino, of switches -iiiy, invention -applied to systems of.. autof(-r con'Lrollih,), the field circuit. Thi's sud-- iiiatic substations. (,e,-i v-.irizition -in the value of the elect@oReferring particularly to Fil1. 1, an alterii)ot,ve -for(@e, or "in(luctive klele', -,is it inay natin,(Irreurrent. motor 1 of tbe.. synebronotis [)(I effects the teniporary de-ener- type has a primary windin- 2 th--.it is SUI)- 300 of su(-Ii -,ictiatillf,- (!o:ils -,is -ire con- plied witli @@ergy b--y iiieans of line condtic-eted to Mv invention 1-clates to motor starters, and it li:'t@, I-elltion to systellis for aiitolii::.tie.tllv ;tartilig syneliroiious motors. .,f is for its object to provide I c,,ntion b. y iliv i qi!iil)le ind effic;eiit arradgement for autoiii.itiezilly elfectint, the acceleration of synn (-Iii-ol)oii-, iiiotor,@, to synchronoiis sp@ed and i',)iinsiirini, the -niaintenance 6f runiiin- coniiec,"ir.ns @iftc-,r they li,,ive been established. 10 s ed, in connecti t.t bz,@ beeii observ on with e,,I)e.rirneiits to determine the various ebarll(!T,Crlsties of synelironous motors, that, if tl,,e field circuit of such motor is closed duriii(- the. startin(, operation, the circuit is 1,5 trliv'ersed by -current of siibstantially const,int value while the motor is accelerating froin' zero to - substaiitially syhehronous spee-,I.: The valtie of the current cirops sudcleiily to-substantiauy zero when the motor '"O i,eiches gynebroiious -sp6ed. The :v,,ilti6 o'L the cu'rrent is substaiitially (,(,Ilstp,nt by reason of the fact that the re:ie,ta,iiee 6f'tlie field circuit is relatively high i@,lille it@,- r6sistance is rel:itively low. -The ce iliduced in the'field-mag-i electromotive for n4it Nvinding @by the t-ransfoime'r' action of the iiiotor dedreases 'a 'the "M'Otor approacbes iii eirettit witli the field-ina,,iiet wind- toi-.-, 3, 4 and 5 , whi may be conn, i h,@ (if the motor. -iny stiitable soiirce of alternatiiig curreiit. Iti i e()penclin(y, -,tpl)lication of Cbesti@r W. Aiitotr-,tnsforiiiers C) siipply enero-y at low Serial No. 389,597. filed Juiie 17 191- >Ol volta,),e dui-iii- the qtartin(y operatioli. 105 i,i-oiioiis iii-)tor st-.i'rters", it lias been Tlle stai-tin- coniiections of the iiiotor are lllil(i@I)tZ(,cl to e,,)nti-ol the connection of the coiitiolled by an elee'Lroiii,,i-netic switch -i .te inc, ex(-- -.- to the fiel(I ina,, iet -%Yinding aiid liinrinan zietuatiiig co'l 8. The runii' t7'

BEST AVAILABLE COP'I 1,633,938 collilections of the inotor are controlled by -in electroiiia(ylletic sivitch 9 havin- an actuzn atin(y co'll 10. The field-n-iagnet ivinding of the motor, .5 which is ctrried by the rot@or 12, is connectecl by iiieaiis of slip rin,(,,s 13 to any suitable soiii'ee of (lire-,t current, sueb, for example, -is t lie tisual exciter (reiierator The nature of the soiii-ce is, liowe@er, i inm-.iterial and line 10 (1011(luctoi@.@ 14 -tnd 15 iiiav be tonnected to an@@ siiltable soitree of diriet current ener,-r . 'Y The fielci circuit COnDectiODs ai-e conti-olled bv a-ii electi-om-,tgnetic sw'tcli 16 of the soe-illelil "Iocl-.oub'l t. e. The switeli 16 coii-iyp i5 priseswel'ogin coil-17thatisener-izedfroiii 9 z@ ttie el-teliit represented by coiiductors 14 in(i The siv-itch is provide(l, also, initli :t ]6e]Koiit coil@ 18 t]@at is iii series witb the fieldiii,i-criiet wilhd'n- (iiii-in- tb'e stai-tina oderi20@ tiol) of the motor. D'tiriiig sucli period, the .9-,v@lteb :1,,- belci iii its open@ poiition.. A pii,otally iiiounte(l tii-niattire iiiember 19, iipoii -%vbiel@i opposiiig foi-ces i,ie (@xei-ted by tl)e i-epecti-,@@ doi,ls 17 a-iid 18, cari-ies -,t. movable 2S col@t- - *t iiiehiber 21 iv]@ieli co,.icts )vitli -,t cont,,i'e.t iiieniber 22 to close the c.;rttit of the ri6f@@l 11'1,,t(,@h-et:.ivindincr -,,%@ben the switeli is iii its open position. Th6 atint@tiire, nieiyiber 19 cirries, tlso, 36 mciv@,@10- -contact i-nemb6rs. 231 and; 9-4, ivli@leli i,egp6I2t]@'Vely c6act witli contact nivi)ibei,s 9-,;i zixid- N th- co-n),pl'etie tbe noi-iiia-I fi'eld cireiiit 6f tl@'e m',otor@ @iid: t6- 6oiitrcil the eitabli,-,Iiill!z 16f, thti 6ihllink Coniieetiol)s 0-1 tlle illot(;@ 3!@ Whie@i fhe@ S'Witcli iE@ el:o--ed'. The eireiiits of detii,qtill@g :@n(l. 10 of the switelies 7 aiid 9i afe@ c'oiitrdlled by :v ti-,iDsfer- relay 28 liav.in& ,iii f@@tit-atiiici @6il 29. The cii-cuit'of the Ititter'cbiil-'is-66wtroll@d by aiii atixil-i@,try relav 40 -30. T-1@,e, au.-xillary, jrelli-y li,.is an aettiating coil 31, the ei-rdbit t)f Wh.ieh-- is e6ntrolled by coiifadt mtrfibei@g; 23@ aiyd 25,. -It as ume(l@ that the inotor 1 i.,3 -it ,r@st an(Il thit the viiii6u,4 switelies ocelipy, 45 thl,6irrd8p6efiN@o-illustratp-d@-pt)sitions. @ltniav bi@@ assily,@,6d ftirt@ei' . that a in-,inual;ly ol)ei;z@bl@e switeli 32 lias beeii closecl to coiiiplete th(Qireiiit, of elbsifiti@oil, 17 ol. the switell 16. It N@i@ll bi@ i-ind;@t@tood tli@i-t-, if the usiiil direct.@,11 co@hyf6etiecl gonerator stippli@es etirrent to tRe Rold-hiqkh6t *indiiig, iio- eleoti-oiiioti ve fot@el,s ir-pp]iEid,to,tbe ceiil i7 iiiitil't.he iiiotoi, i-ot,,ites. In case 1, soiirce (if siibstaiitialiv cohstaht- @electroniotive. force is eiiii)loyed t];@ mvit@ll 32 will iiot be closed iintii i@tei@@t]iL, sf,,ri-tilid i.@,witcli; '( lias clo,,@ed. To tllff niotor, ,t manually - ol-)ei-able 33, i:s illiistr-.itecl is of the I nift@c bILid'e type, is el'osed to energi7,e the conti-ol (;o (,.iTeiiits of the system. Ciirreiit t-l@en tr,,ivei-ses ,v cl@ciii-t -%vhich ext4bi):d8 from con(I'tietor 34 ti i-oii I gla switeli 3@;, ,ictii,-,itin- coil @)e) of- the lo-,v-volti(ye relliy 36. overloid i-el-,iy 117 -,iiicl civiteli 33 to line coiidiie'uor 38. Tli(, all IoNv-vo,t.,I.,Ye i-el;iv "J)6 closes to coiiiplete ,i cll-- cilit for the actuat'n(r coil 8 Of SwitClI 'I. I , This eircu@,t extends from conductor 34 tlii-oucli lo-%v--%,olta(,e relay 36 ,iiid transfer i-eliy 1)8 -wbieli is in its lo-%ver posit'on. and coil 8 fo con(Itictor OQS. TI@e siviteli 7 then cloges to estiblish stirt.'-!n(y coiariections for the n-totoi,. 'Irlie pi-imirv wiiidiii(, 9 is convoll-a(ye til)s of the ii.ito-ti-,iiisiiected to loiy L ' f oi-i-ners 6 iiid cui-l,eiit is siipl)tle(l to t@li(,. iiiotoi- :it i-eclii(-e(I volt-a@(,Ye. rel@itivel Iii,(,Yli clectroiiiotive rot-cc is 37 Yeiiei,atecl in the fi(-@ld eireiilt I)y i-easoii of LI)e i-elitive mov(,i-iient I)etwLeii the i-ot,itiii,@- flux of the arii-iittii-e -,ind tlie. in'lt-ially stiti I (11:illv He](]-iiiigiiet The cii-eiiit of til(@, t@ ],,itter ;s closed it coiitact iiieii,il)ei-s @)l @ii(I 21@ ind the @,eries loci@oiit co'IIL 18, wliieli is inell-i(ied ;@i the fielci i,, eii I ei-,Yize(I to i-etii-@ the ii,iiizittire. 19 of the sw'teli 1C@ in its- open posit,1011. '],'lie ill(t,('- ol)(@i-,ites siit)stiiitiilly as ziii iyir)tor, tlie fi(!Icl- iiii-)iet ,villclillff c(listittitiii(, t st!coiida-i-Y %vin(Iiii(, ivitli itseii-ci,,it elo,;e(I a-nd discoiiiiected fi-oiii the excit(,r oi- ot-her soiit-(,T of dii-e(!t ciii-i-eiit. AlTli(,ii oi) the iiiotot- i-etielies ctibstanti-,illy 3@yiiclil-onolis qpeed, thc@ zilteriiatin-- curi-ent trzrN,ei-sin- tlit@ field fall ,s suddenly t-o - stibstiiitiallv 7,eio viliie. Accordin,--I,'y, tl-i6 loelcout coil 18 is de-enercized. it this iiist,,tnt atid the e]6siii(, coil 17 effects tite closiiio, of Llie switeli 1,6. Tlie- c-ontact iiieiiibers 23 aiid -94, i-espeetiv- ely,- entra-e tlle coiitzi-et iiieiiibet-s 25 and 26 to (@olliplete i; cii-Cilit wliieli ext(@ncls froiii contltictor 14 tbroiigli. coiit,,ict it-ielxibers --)3 25; irettiitin(y coil 31 of alixi', . l@ll-v i-el@ly 30,, slip i-inas 3 -,tntl@ field-iiitigiiet wiiidin(, of the iiiotc@;@@ rlieost-,it 40, aiid (@oiitact iiiembers,.)-l tnd 26 to eonductor 15. '.rlie closin,-. 10.5 of the eiretiit lList tiescribed applies iiordlal exci-tinr, Volta, e to the field-iiiignet xviridiii(y 9 of the iiiotor. Wlien the etirrent. traversing the fiel(I eireiiit i.,eaches ii, predeterniine(I i@,t]-iie, the coil ]lo .31 is eiiet-crized to:clo@,e @tuxilia-i!v relry 30 ancl tlle latt(,r' coiiipletes -,I- cii-eilit "wliieli exteiicis fi,oiii. e6iiduetoi- 34 tlii-otidli siiiteli 33, lowvt)].tige I-eliy 36, zilixil-i-,Irv'@i,el.-ay 30, actiiatin(r eoil 29 of transter rel:iv @28 -.in(] ,witelt 33 to I I eondtictoi- 38. Tlie- ti,,insfer rel,,iy is ictii:i-ted to it,s til)l)eipo.,@itit)i@' t-o o-peil tl-.e (!irci..i:it. of actuitin(' co;l 8 of ,;t;i;i@ti,nr siviteli 9 ind to c@o,@,e the c, ell' ir it of tlie,, actii-atin(y eoil 10 of i-iiiiniiio@ ,NNitell The s-%viteli 7 o-pens to discoiirect tlie.. )Ilotol. fi,oni the aiito-ti-;tnsfoi-iiiei-s 6 ztil(l tlie switell 9 (,loses to effect tile direct coniiection of the I ine con(iiietoi-s i' , 4 iiid @') to the iiiotoi-. The iiiotoi- iionv operites iinder Poi-))@i-,tl i-iiiiiiiii(T 125 con(litioiis -%vitli loa:d volt,,.ge ;rl)pli(@(i to tll:(@, NN-indin- 2 ,ind the iioriii- I exc' 1.)i il iter vol.tiae applied to tli(, f-ield-iiii(,net iviiicliii(, The inereise iii the v,.-Lliie of the ;il)plie@(]' volf.:i-c incicleiit to the iii pi-iiiiary 130 70 7 5

BEST AVAILABLE COP'@ 1- 633,93B colinection.1; Indtices -,in e-lectromotive force aiid ill: that circuit interrupters are subfor the usiial electr o-iiia(riiet le the field circuit which'temporarily cP stitifted I d which : s-witches. ]@oses that of tl-le excitidg source aD mav be of such: as to. p,,trtially or en-he i, tirily de-ener-ize the actuatiiig coil 31 of, t rela,@ 30 and tliereby ciuse the latter to opeii. ,.riie openiii@,, of relty 'o- does: iilot, liowever, n i) ,@ffect tli(@ openings of trinsfer relay 28 be(,,Iiise in interlock 4'-) connected:to the relay closes the lioldinf,- eirciilt of the coil 29 -wlien r:l the i-el,,iy is actiiated t@) ilt-s open positioii. The iiiterval of time between the respective opei-ations of the auxiliary -relay 30 and ol the transfei- i-elay 28 is such as to insure that the transfer reliy 1)8 is closed and that the liolding eireiiit of the coil 29 is coiiiplete(l: before the abnormal electroi-notive force iii-; duced in the field circuit effects the opening of the au-.nli,@.ry relay 30. The provision of -,in atixiliary relay and: the arran-ement wbereby the:transfer relay ivhicli is controlled thereby coml-)Iptes a holdiri(r circuit,for its actuatldg COil effectuall y prevents.tlie opeiiidg of the running.con25 iiections @ of the motor, which might. other-ivis@e@ be. caLis6d by the above-mentibned i-ndticti-%,e distu'rbance in the field.cire-Liit. To stop the motor it is on@v necessary to .,;Open! the s-vvitch. 33, @and thetebv -disconnect 30@ - the cont3@ol-. eircuit@ . from @ the conductors, 34 .and 38.. .!The s*itch 9 thereupbn :opem-3 to:: by the. tra-n@fer reliy 55 or by i ii discotinect tbe- motor, from the line. The operable switch .62. transfer r@lay. 28 falls to its: loweti -positi6n ..::Tlie cii-cuit interrtipter 53 is provided -@vitli to p rtially c6mplete: the circuit . of the - coil a closinr- coil 63 th,-.t is controllecl bv a a 35 8 of st@rtino,@switch-7 in anticipation,.Of -tbe 'f(,-r relil@ 55 and -.t trippin(y coil (@4 tli-,it is 100 -nextz st@ -rolled by a manu-@illy ol@erable switcli 65. O]a: @;; - .. ' I ,,rtino,:operati . :,.@ ! cont Tbe@ &witch,@32 may be,.op6ned at@.any- de-;i; It mav.be -,issumed iliat the ap-.oai-attis i.-, A direct-curi,ent genel-,Itor 45 is directconnected to 4, synelironoiis niotor 40 aiid in 70 exciter geiierator 47. TI)c lilotor 4(; is SUI)plied w'tli onet- f@oiii line coiidtict(,i-.c; 47, I ny 48 and 49, ivhicli tyiiy be cont-,ectccl to aiiy suitible sotii-ce of ,iltetjifttin@, ciii-i-ent. Iii startiii4)- tl)e iiiotoz- i,@.; siil)pl.ed Nvitli 75 Ily tt rediiee(I -t,oltio-e tlirotigh atito -tr:iii.@;foi-iiiers 50 and eirellit iiitei-i-Iipter:3 Zin(i 5,?. The circuit iiiterrui)tei-s. '-)l aiitl .ti-e i-nechanicallv coiinectea for s'iii,,iltzi,ieoiis .icttiation. A circuit intei-rul,)ter con'ui-ols tlik, so direct coi,.iie(:tioii of the iiio@@or to the litif". The circuit of the field-iiit@@iiet ,-)4 of the motor is controllec:C Lv a loul'@'olkit switch 16 coi-respoiidiiig iii evei-v i-esp,--ct tt) the switch 16 of Fig. 1. An. a-Li@lll,.irv re@l,Iv 85 30, having an actup.@Ling coil 31, ZDcl. a' fer reiay 55, liavino@ ,in 2 etuatin(,, coil, 56. are controlled by the lockotit s-%N-iteli 16. The; eirciilt interrupters 51 and 52 liave closing coil 57 . ai-icl Ici ti-ippin(y coil 58. 'I-lie oo coil. 57 is controiled bv a relhy 59 tl),,It -Nvhen the voltage of Che 'Lrolley ivire 60 -ILzilis to a pi-edeteriiiined value. The coil 57 mav also be controlled b3,- a riiiini-i,,illv opei-abie 'switch 61... The tripping coil:',@',S ;.s controlled 95 -ianii! liv Sired- time:th ere after -tu-.e:ffect the openingof@, -the@field ci@cuit by-the.s*il@h.II6. .;,.The.open- 'is open. It may be ,i@s@ii@ed..f@irther, tli,,it 4o:ing: of;the@ switch -la;effeets't heiclbsin-.@of'ithe,voltage@ot tlieiti-olley c6@di.@et6i-,j6O b:is -'' ' ' d v c6ntact'members@21'and 22 to,close the@ fieldf:,fallen-to.a, predetermine aliie at ivliieli the circuit in readines 't .for! the; successive - start- rela 50. closes..', ,V circuit is coinpleted, y ing: 6 er-ation. iwhich. extepd,% froin coiiductor 67, -%,vli;.cli .p By means @ of the . arrangeinent, recited. - .may be - conne'eted to aiiy suitable sour6e of 45 above@ it; is possible to, - e:ffect: the f auton@atic :,direct eurrenti throiioli relay 59, cl6sin(r coil acceleration.of asynchron6us motor:to.svn-, 57 of - eire'uit interkuptei-s 51 ,t.ncl 52 and iiichronous s@e.ed and-to connect it.to the fi'ne terloe'l- . 68- of. circiiit interrtipter 53 . to coiiat the proper; instant.@ ;T. he@ ent4e operat.ion, ductor.69. niay betiniti@ted.by,the-actuation Df a,single T-he@ cil@6iiit iiitu,@i-tipte s 51 and 52 close r ,50:.In.lnually,@.operable switeli or.:p.Llsh-button . to connect tb-e iiiotor 46 to the Iiii(! switch, - The-.auxiEary,@ire6rlar and the@ @oldy in" circuit for the.traii . elay.iinsure that i.ite norftial connecti ons of the motor' f'kr" ' ' e. not disturbed by: abnornial volt4gp@@ in ;the field .,5 circuit wbieli m4y.be, caused by:tlie change@ of coiiinections durii) the stai-tin o, operation. Refer,eiace may be.had to Fig..2. in %Yhich i-ny.inventioii is il]Listrated,as applied to a, svs ill te of control for. a n aiiiomatic subt"( statio@ sue]) as i-nav be en-iployed.in conneetioii iyitl-t electi-ic'railways @r siiiiilar systeiii@,. The svstem differs principall from. I y tliat' desei-ib@cl above. in that its operationniay be dependent upoii voltaoe conditioiis. 6 ,> of. the trolley line to whicli.it stipplies enerky and. that: a -I in re it e ei u breaker 66 the iuto-'Lraiisforii@ers 50. The niol-or ace@.1erzites uiide'r the c-3nditions. d-escribed in coii@: . . .. f F'-. 1. At the iaectioii ivltll the systeiii o it:" instant the i3iotor reacli6s synchroiiotis spee(l, ihe-siyiteli 1G closes to coiiiiect the exciter 47 ]2t) iii eir(-iiit %vitli the fi@ld-)iiig t vindin 4 lie .5 of the motor. The closin(, of the @wit(-.Ii 16 .11.@0, to @olliplete tl-ie eir'ciiit ()f cietii-itin(,, coil 31 of aiixiliit-y ielty 0 - ( 3 1111 tile I-Itter clo-@es to effect the closiii(, of t-i-,iisfeij--elav . Tiie clos . iii" of tlle relay @')! eite(-ts tlle of tripl)lii(,@ coil 58 (,,f cireiiit interriidtei-s 51 aii(I .5-? iiicl tlic. latter accorclinyly,, opLiie(.1. Tlie, traiisi'ei- at .-,o