US1344210A - richardson - Google Patents

Description

"IL G. RICHARDSON. AUTOMATICITELEPHONE REPEAJEB. APPLICATION FILED A/UG.23, IIJ/I6.

1,344,21 0. Patented June 22, 1920.

)a 73 jj R. G. RICHARDSON.

AUTOMATIC TELEPHONE REPEATER. APPLICATION FILED Amma, 191s.

1,344,210, Patented June 22, `1920.

UNITED STATES PATENT GFFICE.

RODNEY s. RICHARDSON, or CHICAGO, ILLINOIS, .assIefNon To AUTOMATIC ELECTRICv COMPANY, or CHICAGO, ILLINOIS, A CORPORATION or ILLINOIS;

AUTOMATIC TELEPI-IONE-REVPEATER.

l Speccaton of Letters `JSatent. Patented J 111-19 22, 19,20.v

Application iled August 23, 1916. Serial No. 116,483.

To all @07mm t may concern.' Y

Be it known that I, RODNY Gr.V RICHARD- soN, a citizen of the United States of America, and a resident of Chicago, county of Cook, and State ot Illinois, have invented certain new and useful Improvements in Automatic Lelephone-Bepeaters, of which the following is a specification. My invention relates in "general to repeaters ior automatic telephone systems, and has for its principal object the provision oi means in such repeaters tor transmitting impulses of uniform length regardless of irregularities yin the length of the received im ulses. y

n modern multi-office automatic systems in which the automatic switches are directly controlled by impulses transmitted from the individual Subscribers calling devices considerable diliculty has been experienced in adjustingr the length 'of impulses delivered by the calling devices sovas to insure accurate and rapid Operation of vthe switches in different oiii'ces. This cliiiiculty is largely due to differences in the capacity and resistance of the trunks and is accentuated by variations between the individual 'callin g devices themselves.

Hy improved repeater is adapted to re-" placed in order` with the lines at the ends thereoiE in alinement, represent diagrammatically a complete circuit connection be- Ltween a calling substation A and a called Referring now to Fig. 1, the substation A may be ot any approved automatic type, such, for example, as the substation shown in British Patent to Martin, #1419 of 1910. As represented herein, iticomprises essentially the receiver 2, transmitter 3, switch hook 4, ringer 5, and condenser 6. Being an automatic substation, there is also provided a pair yof impulse springs 7 and 8 controlled by an impulse wheel 9 through the medium of a linger hole dial (not shown).

' The line conductorsll and 12 of the substation A are connected at the exchange to the" individual'line switch C which is of the general type of lineswitch disclosed in the British Patent to James #26,301 of 190e;

,beipjgg however, of the particular Vtype Shown in S. Letters Patent #1,078,690, granted Jan. 17, 1912, to Frank Neworth. Since line switches of the above description are well known and form no part of my inventionthey will not be described in detail. It will lsuilice to say here that through the medium ot' line switch C the line of substation A'whencalling is given access to a plurality of trunk lines extending'to Selector switches.

The line switch C and a plurality oi similar line switches are controlled Vin their trunk selecting operations by means of a master switch D. The masterswitch rD is ot the general type jo master switch disclosed in the above-mentioned British Patent to J ames, #26,301 of 1906; being, however,

Switch C has access is Shown in Fig. 1 extending to the selector switch E. The selector E may be ofthe general type of selector switch` disclosed in IIS. LettersPatent #815,321, granted Marchf13,1906, to Keith, Erickson, and Erickson; being, however, olfy the particular rtype disclosed in British Patent to the'Automatic Telephone Mfg. Co., #2543 of-1914. A 'selectorswitch of the :foregoing description, when used in a multi-oiiice system such as. contemplated herein, may be operated in response to the.

irst digit of a called number to select one of the main groups or exchanges into wnich the subscribers lines 1n the system are divided. For this purpose` the selector E, in

`common with other selectors, may be given access to a number of groups of trunk lines, each group of trunk lines extending by way of repeaters to a different exchange.

One of these trunk lines is shown extending from the bank contacts 73, 7-1, and 75 by way of conductors 80, S1, and S2, repeater l (Fig. 2), and trunk line conductors 83 and 8.4 to the selector F. The repeater It is, of course, introduced into the trunk circuit primarily for the purpose of obviating the necessity of continuing the third conductor, conductor S1, to the distant exchange; but in accordance with my invention this repeater also has another function, that of standardizing' the impulses, which will be fully explained hereinafter.

The selector F is similar to the selector E, already described, and is operable in response to the second digit of a called number to select one of the groups into which the lines of the exchange are divided. To this end the selector F in common with other similar selectors, is given access to a number of groups of trunk lines, each of which groups extends to a group of connector switches which areV adapted to complete connections to a group of individual lines.

In Fig. 2l one of these trunk lines is shown extending from the bank contacts 173, 17 1, and 175 to the connector H (Fig. The connector H may be ofthe general type of connector switch disclosed in U. S. Letters Patent #815,176, granted March 13, 1906, to Keith, Erickson, and Firickson; being however, of the particular type disclosed in U. S. Letters Patent #13,901, reissued April 13, 1915, to Frank Newforth. A. connector switch of the foregoing type may be operated in response to the two last digits of a called number to connect with an individual line in the group to which it has access.

One of the lines accessible to the connector H is the line extending to substation A which substation, together with its associated linc switch C, may be similar to the substation A and line switch C in Fig. 1.

To supply current for operating and talking purposes I have shown the batteries B and B each having its positive pole grounded. The auxiliary pieces of apparatus associated with the connector II comprising the ringing current generator Gen, the ringing interrupter I, and the busy signaling machine Q are of the ordinary type and perform the same functions as the same named pieces of apparatus in other automatic exchanges.

Having given a brief description of the apparatus, I will now proceed to a description of the operations of the same. For the purposes of this explanation it will be assumed that the subscriber at substation A desires to obtain connection with the subscriber at substation A. Inasmuch as a great deal of the equipment shown herein is old and well known in the art, having been fully described in the publications previously referred to, the operation of such equipment will be described in a more or less general manner.

Referring to Fig. 1, when the subscriber at substation A removes his receiver to initiate the call, an energizing circuit is coinpleted. over the line conductors 11 and 12 for the line relay 16 of the line switch C. Upon attracting its armature, the line relay 1G closes a circuit for the pull-in winding 17. Upon energizing, the pull-in winding operates both the plunger arm 21 and the cutoft" armature 22; the former through the medium of its plunger (not shown) forcing the bank 4springs 30-33, inclusive, into engagement, respectively, with contacts 341-37, inclusive; and the latter disconnectthe line conductors 11 and 12, respectively, from ground and from the line relay 1G. By the engagement of bank springs 3l) and 33, respectively, with contacts 341- and 37, the line conductors 11 and 12 are extended to the double-wound line relay (3() of the se` lector E.

The line relay G() is accordingly energized over the loop circuit including substation A and, upon attracting its armature, closes a circuit for the slow-acting release rela-y ('51. Upon energizing in turn, the relay 61 completes a holding circuit for the line switch C which may be traced as follows: Ground at (i7, contact springs 91, contact 35, bank spring 31, and holding winding 18 to battery B. Since the line relay 1G is slow-acting, it retainsits armature to maintain the pull-in winding 17 energized until after the above holding circuit has been established. A branch of the holding circuit extends by way of conductor 19 to multiple test contacts in the banks of connector switches having access to the line of substation A where by a ground potential on these test contacts the said line is made busy. By the engagement of bank spring 32 with contact 36 the master switch D is operated in well known manner to adi'f'ance the plungers of all the remainingidle line switches into position before the terminal of the next idle trunk line.

The foregoing operations whereby the line conductors 11 and 12 have been extended through to the line relay G0 of the selector E have takenA place in response to the removal of the receiver at substation A. The calling subscriber may now manipulate his dial in accordance with the first digit of the desired number, thereby separating momentarily the impulse springs 7 and 8 a number of times and interrupting each time the circuit of line relay 60 of selector E. As a result of these interruptions of its cir cuit the line relay 60 is denergized a corresponding number of times, sending an impulse at each denergization from ground at Gr to the slow-acting relay 62 and the vertical magnet 65`in series. The vertical magnet in response to these impulses steps up the switch shaft until the wipers 70, 71, and 72 stand opposite the horizontallevel in which are located Vcontacts which are terminals of trunk lines extending to the exchange in which the wanted subscriber is located. The relay 62, being slow-acting, vretains its armature during the series of impulses and closes a circuit for the test relay 64, which latter relay prepares a circuit for the rotary magnet 66 and locks itself to ground at G7. At lthe* end of the series of impulses the relay 62 denergizes, thereby completing the aforementioned circuit of Athe rotary magnet 66, whereupon the wipers 70, 71, and 72 start rotating in search of an idle trunk line. As Vis well known, the

rotary magnet interrupts its own circuit ungrounded test contact the test relay 64 denergizes and opens the rotary magnet circuit, thereby bringing the wipers to `rest upon the terminals ofan idle trunk line, assumed to be in this case the contacts `73, 74, and 75. As a further result of the deenergization of thetest relay 64, a circuit is completed for the line switching relay 63 which relay, upon energizing, disconnects the extended line conductors 12 and 11 from the windings; of theline relay 60 and further extends them by way of wipers and 72, bank contacts 73 and 75, and conductors S0 and 82 tothe line relays 100 and 101 of the repeater R. The line relays V100 and 101 are accordingly energized over the calling subscribers loop. Relay 101,

ground at G, circuit springs 115 and 116,

conductor 81, bank contact 74, and wiper-,71 to wire junction 92, where the circuit divides, one branch extending by `way of normally closed circuit springs of relay 64 and the winding' of line switching relay 68 to battery B, and the Vother branch extending by way of oil-normal contact 9?; 7 and inresult of the energization of relay 102 a n circuit is prepared for relay 103 by theolo-4 sure of contact springs 119 and 120, and in addition a circuit is completed for the double-wound line relay 160 'of the selectorv F which may be traced as follows ground. at G1?, lower winding of relay 160, contact springs 96 and 97, conductor 84, contact springs 113 and 114, contact springs 118 and 117, contact springs 124 and 125, winding 'of impedance coil 105, contact springs 121 Vand 122, conductor 83, contactsprings99 Vand 98, and upper winding of relay 160A to battery B.V Upon attracting its armature,

'the line relay 160closes an energizing cir-V cuit for the slow-acting relay 161 which relay upon energizing, prepares circuits for y the vertical and rotary magnetsr of the selector F in the usual manner. A

Having disposed of the circuits controlled by the line'relay-101 of the repeater we will now consider the line relay 100. Upon the` energization of this latter relay a charging circuit for the condenser 106 is closed over the following path: ground at G12, contact springs 107 and 108 and condenser 106 to battery B. The condenser 106 isV therefore at once charged to the potentialy of the bat# tery B. The Contact springs f 109 vand-107 of relay are preferablyso adjusted that at about the middle of the armatures stroke the contact spring 108wll leave contact spring 109 Vand at the same time or an instant'later will come'into engagement with contact spring 107. f

The calling subscriber may new proceed to dial the second digit ofthe desired number, resulting as before `in.interruptionsof his loop to which the line relays 100 and 101 are now responsive by Vretracting their arma Y tures a corresponding number of times. At

the first denergization of relay 101 a circuit iscompletedf` for theslow-acting relay 103 as follows: ground aty Gd@V contact springs 110 and 112, contact springsr120 and 119, and winding of relay 103 to batteryB. Relays 102 and 103, being slow-acting, retainv their armatures in operated position duringl a series of denergizations of relay 101, after which relay 103 retracts its armature. In its energized-condition relay 103 disconnects Y the conductorsV 83 and 84 from the 'conductors 80 and 82, respectively, and from the normally bridged impedance coil 105; and

substitutes for the latter a direct path by way of'contact springs 123and '124, contact springs 117 and 118, and contact springs 114 and-113, 1

At each denergization of the line relay 100 the left hand terminal of the condenser 106 4is connected to the lower terminal of relay 104 by way of contact springs 108 and 109. The condenser 106 is therefore discharged through the winding ofrelay 104 and as a resultv of the discharging current the relay 104 is operated momentarily to separate its contact springs 113 and 114. Since the condenser 106 receives a new charge at each energization of the line relay 100, it follows that the relay 104will be operated at each denergization of the said line relay to repeat the interruptions of the subscribers loop into the previously described energizing circuit of the line relay 160 of the selector F.

In response to these interruptions of its circuit the line relay 160 operates to control the selector F in precisely the same manner as lwas described in the case of the selector E, whereby the wipers 170,171, and 175 are raised step by step until they stand opposite the proper horizontal level of bank contacts, after which they are automatically rotated until they arrive at contacts, assumed in this case to be theV contacts 173, 174, and 17 5, which are terminals of an idle trunk line. The wipers having been brought to rest upon the contacts of an idle trunk line, the line switching relay 163 is energized to disconnect the line conductors'83 and 84 from the line relay'160 and extend them instead by way of wipers 170 and 172, bank contacts 173 and 175 to the double-wound line relay 200 of the connector H. Upon-attracting its armature, the line relay 200 closes `an energizing circuit for the slow-acting relay 201 which relay, upon energizing in turn, completes a holding circuit from ground G1 for the line switching relay 163 of the selector F in the usual manner.

The calling subscriber may now manipulate his calling device in accordance with the third digitl of the desired number, thereby causing another series of denergizations of the line relays 100 and 101 of the'repeater R. As'before the relay 104 will be operated by successive discharges from the condenser 106 to produce a series of interruptions in the circuit of the line relay 200 of the connector H. Responsive to these interruptions the line relay 200 denergizes a corresponding number of times and sends each time an impulse from ground at Gr17 to the slowacting relay 207 and the vertical magnet 204 in series, side switch wiper 215 being in its first position. The vertical magnet, in rcsponse to these impulses, steps up the shaft until the wipers 220, 221, and 222 stand opposite the horizontal level of bank contacts in which the line of substation A terminates. Relay 207, being slow-acting, retains its armature during the series of impulses and maintains a circuit from ground at G1S for the private magnet 208 and the wiper cut-ofi' relay 211 in parallel. At the end of the series of impulses, the relay 207 denergizes and breaks the circuit of the private magnet, which latter controls the side switch wipers in the usual manner to advance them to their second position.

The subscriber at substation A may now operate his dial in accordance with the fourth and final digit of the desired number, resulting as before in denergizations of the line relay 200. Now, however, side switch wiper 215 being in its second lposition, the line relay sends impulses to the slow-acting relay 207 in series with the rotary magnet 205. The rotary magnet operates in response to these impulses to rotate the wipers 220, 221, and 222 until they rest, respectively, upon vbank contacts 223, 224, and 225, these contacts forming the terminal of the line of substation A in the bank of connector H. The private magnet 208 and the wiper cutoff relay 211 are energized during this series of impulses as before, the latter disconnecting the line wipers during rotation and the former, upon denergizing, controlling the side switch wipers to advance them to their third position, it being assumed that the line of substation A was idle when called.

As side switch wiper 214 comes into engagement with its third position contact point, a circuit is completed for the cut-0H winding 18 of line switch CV as follows: ground at-Gl, side switch wiper 214 (in third position), wiper 221, bank contact 224, and winding 18 to battery B. By the closure of the above circuit the cut-off armature 22 is operated to disconnect the line conductors 11 and 12', respectively, from ground and from the lin'e relay 16. Ground at G19 also extends to multiples of bank contact 224 in the banks of other connectors of the group, thereby making the line of substations A busy to other calls.

By the engagement of side wipers 212 and 213 with their 'third position contact points theA connection between the calling and called substations is completed, relay 211 being denergized. By the engagement of side switch wiper 215 with its third position contact point, a circuit is completed for the ringing relay 209 in series with the interrupter I, whereby ringing current is projected intermittently out over the line of substation A to operate the signal in bridge thereof.

The subscriber at substation A has now established the required connection with substation A and the bell at the latter substation is being rung to attract the attention of the called subscriber. When the called subscriber removes his receiver from the hook a circuit is completed for the doublewound back bridge relay 202 in the well it is prrn'ided in case it is desired t0 operate,-

nietcrs or similarapparatus.` c

The callingand called subscribers may now converse without further effort. Currentfor the transmitter at substation A is supplied through the windings of the line relays 11,00 and 101 of the repeater' R-while current for the transmitter at substation A `is supplied through the windings of. the

back bridge relay 202. Y The voice currents follow the path shown in the heavy lines which, it is thought, will be apparentvwithout furtheramplifying the` explanation.

Then the conversation is completed both subscribers will hang up. their receivers. By the replacement of the receiverl at substation A the circuit of the line relays 100 and 101 of the repeater R is broken. Upon denergizing, relay 100 operates relay 104 again momentarily to transmit another impulse to the connector H but this impulse is of no particular consequence. vBy the deenergization of relay 101 thev circuit of slow.- y

acting :relay 102 is broken. Upon deenen gizmg, relay 102 removes ground G11 from the holdingcircuitextending backto the selector E andthe line switch C, whereupon these switches will restore to normal in the usual and well known manner.` As a further rcsult of the de'energization of relay 102 the energizing circuit for theline relay 200 of the connector H is broken at contact springs 117 and 118. The line relay 200 is accordingly denergizedand causes the deenergization Eof relay 201. By theglatter operation ground G1 is removed from the holding circuit of the selectorF anda circuit is closed for the release magnet 203 of the connector H, whereby these switches are also restored to normal.` Y

The operation of a connector switch such as the connector Il when connection is attempted with a busy line is well known and has been fully described in the publications previously mentioned. Since my yinvention involves nothing new in connection with this feature of the operation 4the description thereof will be omitted.

Considering now more in detail the man* ner in which impulses are standardized at theY repeater R, the operation `depends upon the fact that at each defe'nergization of the -line delay 100 a uniform current is delivered to the relay 104 from the condenser 106,

That this is true will be evident when it is considered that a condenser, when connected directly across the terminals of a battery,

' will .be charged instantly to nearly the full potential of the battery even though an in# finite time is required.theoretically for it to attain its full charge,` lt makes practically` no difference therefore in the amount of charge received byv the ,condenser howlong thecontact springs 107 yand 108 remain together on successive energizations of the. line relay. rlhe condenser receives nearly a Y full charge within a very small fraction of a Y second after these springs make contact and their continued engagement can increase this charge but little. The relative values of the capacity of the condenser 106 and the resistance of the relay 104 are of importance yin the practical operation of the device for these factors determine the time required for each discharge of the condenser and there-foret@ a certain extent the length of the impulses delivered. 1 have found in tests that a condenser with a capacity of 5 niicrofarads anda relay with a resistance of 1000 ohms give good results.

Referring now Ato Fig. 4, the repeater R is exactly the same `as repeater R except for the circuit of the condenser 106 and the relay 1042111 the circuit, Fig. 4, the condenser 106 is short-circuited and therefore discharged at each energization of the line relay while at each denergization of the -line relay 100the condenser 106 is charged in series with the relay 104. rlhis is just the reverse of the operations which take place in the case of repeater lt but the result is the same, for the condenser is for, all practical purposes completely discharged each time, and receives each time a charge 105 which is to a great ,extent independent of the length of the contact between the springs 108 and 109. The modification shown in Fig. 4 is rather an obvious one but it has been thought best to show the circuit. s

Other modifications. can doubtless be made to adapt .the invention to other types of automatic telephonesystems or even to other` uses altogether, and I doy not, therefore, wish tov limit the scope of the invention to 115 the precise circuits shown. That l consider to be new and desire to have protected by Letters `Patent will be pointed out in the appended claims. j Y l What l claim as my invention is:

1. In an automatic telephone system, th combination with a circuit controllingrelay, v of la, condenser, and a secondl relayV for charging and discharging said condenser to thereby operate said controlling relay, the pathfor discharging currents including said controlling relay, and conductive paths from the opposite' sides thereof to the opposite sides ofthe said condenser.

2. In an automaticV telephone system, a

circuit controlling relay, a condenser, a charging circuit for said condenser including a source of current, a continuous conductive discharging circuit for said condenser including said controlling relay, and a second relay for controlling said circuits to thereby operate said controlling relay.

3. In an automatic telephone system, a device for repeating impulses, said device comprising an impulse sending relay, a condenser, and a second relay provided with means for operating said first relay through the medium of said condenser.

4;. In combination, a circuit, a controlling relay therefor, a condenser, a second relay and an energizing circuit therefor, a charging circuit for said condenser closed by said second relay when energized, and a discharging circuit for said condenser closed by said second relay when denergized.

5. In combination, a first circuit, a second circuit, a relay bridge across the first circuit, a condenser, means for closing said first circuit to operate said relay bridge, means controlled thereby for charging said condenser and for closing said second circuit, a relay for opening said second circuit, and means for interrupting said first circuit, said relay bridge responsive to such interruption for discharging said condenser through said second relay.

6. In combination, a first circuit, a second circuit, means responsive to the closure of the first circuit for closing said second circuit, a relay for transmitting impulses over the second circuit, a condenser, arelay controlled by impulses received over the first circuit for charging and discharging said condenser, and a circuit for the discharging currents through said first relay.

7 In a telephone system, a trunk line divided into two sections, the second section terminating in an automatic switch, and an impulse repeater joining the two sections of said trunk line, said repeater comprising a relay controlling the continuity of the second section, and a second relay controlled over the first section and adapted to control said first relay through the medium of a condenser.

8. In a telephone system, a trunk line divided into two sections, Vthe second section terminating in an automatic switch, and a repeater joining the two sections of said trunk line, said repeater comprising an impulse sending relay for controlling said switch, a condenser, and a second relay controlled by each impulse received over the first section to charge said condenser and discharge it through said first relay.

9. In a telephone system, a trunk line divided into two sections, the second section terminating in an automatic switch, and an impulse repeater oining the two sections of said trunk line, said repeater comprising an impulse sending relay for controlling said switch viaV the second section of said trunk line, and a second relay responsive to impulses received over the first section of said trunk line for controlling said first relay through the medium of a condenser.

10. In-a telephone system, a trunk line divided into two sections, the second section terminating in an automatic switch, and a repeater provided with means for transmitting impulses from one section' to the other, said means comprising a condenser, a relay controlled over the first section for charging and discharging said condenser at ever impulse, and a second relay in series wit said condenser for repeating said impulses into the second section.

11. In a telephone system, a trunk line divided into two sections, the second section terminating in an automatic switch, and a repeater provided with means for transmitting impulses from one section to the other, said means comprising a condenser, a relay controlled over the first section for charging and discharging said condenser at every impulse, and a second relay controlled by the discharge current from said condenser for repeating said impulsesV into the second section.

12.y In combination, an impulse controlled switching device and a controlling circuit therefor, a second circuit, means for producing operating impulses in said second circuit, and a device for repeating impulses from the second circuit into said controlling circuit, said device comprising an impulse sending relay associated with said controlling circuit, and a relay in said second circuit responsive to impulses therein for controlling said first relay through the medium of a condenser.

13. In combination, an impulse controlled switching device and a controlling circuit therefor, a second circuit, means for producing operating impulses in said Vsecond circuit, and a device for repeating impulses from the second circuit into said controlling circuit, said device comprising an impulse sending relay associated Awith said controlling circuit, a condenser, and a relay in said second circuit responsive to each impulse therein to charge said condenser and discharge it through said first relay.

14. In an automatic telephone system, an automatic impulse correcting repeater, said repeater comprising an impulse sending relay, a condenser, a relay responsive to received impulses for alternately charging and discharging said condenser, and circuit so arranged that upon each discharge of said condenser the said impulse sending relay.

is voperated by current stored in the said condenser during the previous charge.

15. In a telephone system, a device for simultaneously repeating and standardizing electrical impulses, said device comprising an. impulse receiving relay, an impulse transmitting relay, a condenser, a battery, and circuits controlled by said impulse receiving relay whereby said condenser is alternately charged from said battery and .discharged through said impulse transmitting relay to operate the same.

16. In a telephone system, an electrical impulse correcting repeater, comprising an impulse receiving relay, an impulse transmitting relay, and circuits including a battery and a condenser whereby the latter relay is operated by the vformer by current stored in said condenser.

17. The combination with a relay anda battery, of a conductor joining one pole oi said battery to one terminal of said relay, a condenser' having one terminal connected to said conductor, a switch for connecting the other terminal of said condenser alternately to the other terminal of said relay and the other pole of said battery, and an armature for said relay operated by discharge currents from said condenser.

1S. The combination with a condenser, of a circuit therefor having two branches, a magnet in one branch, a battery in the other branch, means for closing said branches alternately, and an armature for said magnet operated upon the closure of the associated branch.

i9. The combination with a relay and a condenser, of means for repeatedly discharging said condenser through said relay to operate the same, and means for charging said condenser between successive discharges thereof.

20.',The combination with two circuits containing respectively a battery and an electromagnet, of a condenser, and suitable means Jfor connecting said condenser in said circuits in alternation, whereby electrical energy may be transferred from the battery circuit to the other circuit to operate the magnet included therein.

2l. The combinationwith a source of electrical energy anda receiving circuit including an electromagnetically operated de-` vice, or' a condenser, and suitable means for alternately charging said condenser from said source and discharging it into said circuit to operate the said device.

22. The combination with a battery and a magnet, of a condenser and a circuit therefor, and means for completing said circuit alternately through said battery and said magnet to operate the latter by means of current stored in said condenser.

23. The combination, with a rst circuit and a second circuit, of a repeater comprising a condenser, a relay in said first circuit responsive to impulses received thereover to alternately charge and discharge said condenser, anda repeating relay in the discharging circuit i'orproducing impulses in said second circuit, the said repeaterr constituting means for correcting irregularities in the received impulses, whereby a series of irregular or excessively long or short impulses is translated into a series of uniform impulses of standard length.

bigned by me at Chicago, Cook county, State of Illinois, this 4th day of August,

' V` RODNEY RICHARDSON. i

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