US1281811A - Testing system. - Google Patents

Description

L. A. MORTIMER.

TESTING SYSTEM.

APPLICATION FILED MAR. 8. |918.

Patented 001;. 15, 1918.

mmm.,

ered in connection with LOUIS A. MORTIIVIER, OF NEW YORK7 N. Y., ASSIGNOR TOWESTERN ELECTRIC COMPANY,

INCORPORATED, 0F NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TESTING SYSTEM.

Specification of Letters Patent.

Patented Oct. 15, 1918.

To all whom it may concern:

Be it known that I, LOUIS A. MORTIMER, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Testing Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to testing systems and more particularly to such systems employed in testing apparatus of telephone systems. l

An object of this invention is to provide a simple, accurate, reliable and inexpensive testing system for testing apparatus associated with toll cord circuits employed for interconnecting toll lines or toll lines and trunk circuits with which may be joined the local line.

More specifically stated, this invention contemplates the provision of apparatus and controlling devices and circuit organizations embodying such apparatus and controlling devices by means of which alternating current and direct current supervisory relays of ,toll cord circuits may be quickly tested under conditions simulating those met in actual service.

This invention will be more fully understood from the following description considthe accompanying drawing illustrating one embodiment thereof.

Referring to the drawing a toll cord circuit A is shown above the dotted line 2, 2 and to the left of the dotted line 3, 3, a testing circuit B is shown to the right of the dotted line 3, 3, and a circuit controlling device C is shown below the dotted line 2, 2 and to the left of the dotted line 3, 3.

The toll cord circuit A terminates in two plugs 4 and 5 by means of which connection may be made with the jacks of two toll lines (not shown) or with one toll line and with a toll switching trunk circuit (not shown) through which connection may be made with a local telephone line (not shown). An alternating current supervisory relay 6 associated with the toll cord circuit A is controlled by alternating current over a connected toll line to control a supervisory signal. The toll cord circuit A is also provided with a direct current supervisory relay 7 which may be controlled by direct current over a connected toll switching trunk circuit to control a supervisory signal.

The testing circuit B is provided with Va plurality of multiple jacks 10 and 11 with either of which the plug 4 0r the plug 5 may coperate to connect the cord circuit A with the testing circuit, thereby to associate the alternating current relay 6 and the direct current relay 7 with the testing circuit. In order that the direct current relay 7 may be tested under conditions simulating those met in actual practice, the testing circuit is provided with two interrupters 12 and 13 which, when connected in circuit with the direct current supervisory relay 7 and a source of direct current cause the intermittent energiZation-of the relay. The interrupter 12 is provided with a relatively large number of segments so that the circuit of the relay 7 may be interrupted rapidly. vA high resistance 14 is in circuit with the interrupter 12. A source of direct current, interrupter 12 and the resistance 14 may be considered as a source of intermittent current which simulates a long toll switching trunk which is opened and closed rapidly. The interrupter 13 is provided with a relatively small number offsegments in circuit with which is a low resistance 15. A source of direct current, interrupterV 13 and the low resistance 15 may be considered as a source of intermittent current which simulates a short toll switching trunk which is slowly opened and closed.

In order that the alternating current relay 6 may be tested under conditions'simulating those met in actual practice, the testing circuit B is provided with a source of alternatin current 16 and an articial line. The artificial line comprises series resistances 17 18, 19 and 2O and a bridged resistance 21. Another resistance 22 is normally short-circuited but when the short circuit is removed this resistance 22 is included in series with the resistance 21. These two resistances 21 and 22 then serve as a single bridged resistance. The inclusion of this resistance 22 in the bridge serves to'alter the electrical characteristics of the artificial line. In fact, when resistance 21 comprises the bridged resistance, this resistance and the series resistances may be considered as one artificial line and when the resistance 22 is included in the bridge with the resistance 21, these two resistances and the series resistances vvmay be considered as a second artificial line. When resistance 22 is short-circuitedand the artificial line and source of ringing Acurrent 16 are connected with the alternating current relay 6, the relay 6 receives minimum ringing current, but when the short circuit is reconnected with a jack 9 associated with the testing circuit B, the lcircuit controlling device C may be associated therewith. The

keys of the circuit controlling device C cont'rol the circuits of a plurality of relays in vthe testing circuit B which, in turn, control the connection of the sourcesof intermittent current, the artificial lines and-the source of alternating current with the `direct current land alternating current supervisory relays. Y v

Having in mind this brief description of the apparatus employed in the testing systeni, it is thought that the invention will be more fully understood from a" description of Vthe operation thereof.k

Testing of direct current relay. Desiring to test the supervisory relays of ,thertoll cord circuit A, the plug 4 thereof may be inserted in the ack 10, and the plug 37 is inserted in the jack 9. 1f it is desired first to testv the direct current supervisory relay 7, the key 30 is depressed into its locking position, whereupon relays 40 and 41 of the. cord circuit A and relay 42 of the testing circuit B are operated over a circuit from battery through the left-hand winding of relay 40, the windings of-,marginal relay 43 and relay 41, sleeve contacts of the plug 4, the jacks 10 and 9, and the plug 37, resistance 44, contact 45 of key 32, contact '46 of key 30, tip contacts of the plug 37 and the jack 9, and the windings of relay 42 and marginal relay 47 to ground. As already stated relays 43 and 47 are marginal and do not operate when resistance 44'is included in circuit therewith. The operation of relay 40 causes the operation of quick operating and slow releasing relay 24 to open the circuit of a la1np25 and a slow operating relay 26 before the relayV 26 can operate. The operation of relay 42 causes the intermittent operation of the supervisory relay 7 over a circuit from battery through'resistance 43, middle normal contact of relay 47, lower contact of relay 42, ring contacts of-the jack 10 and the plug 4, retardation coil 49, winding of supervisory relay 7, normal contact of marginal relay 43, retardation Ycoil 50, contact of relay'41, tip contacts of the plug 4 and the jack 10, upper contact of relay 42, upper normal contact of lrelay 47, normal contact of relay 51, resistance 14 and interrupter 12 to ground. 1f the relay is-properly adjusted it will operate intermittently and cause the intermittent lighting of supervisory lamp 52. If the lamp does not light Vor if it lights and remains lighted the testing operator then knows that the relay 7 is notproperly adjusted to oper- Aate lon this low current when its circuit-is interrupted so rapidly. The testing operator will therefore adjust the relay until it functions properly. -The relay having been vtested under conditions of maximum length circuit, the testing operator then proceeds to test it under conditions of minimum length of line with slowopening and closing of its circuit-which is done by the depresof line with rapid opening and closing of its sion of the key 31. Upon the depressionof the key 31, theikey 30 is restored to normal position and rela-ys 40, 41, 42 and 51 are operated'. The first three of these relays are operated over the same circuit as hereinbef fore traced, withthis exceptiointhat contact 5.3 of the key 31 instead of contact 46 of the -k'ey 30 is in the circuit. Relay 51 operates over a circuit from battery through Vthe left- Vhand winding of relay 40, windings of relays 43 and 41, sleeve contacts of the plug 4,

the jacks 10 YandV 9 and theV plug 37 to the point 54, VfromV thence through contact 55 of the key 31, ring contacts of the plug 37 and the jack r9, lower normal contact of the termittently, causing the intermittent lighting of the lamp 52.` The continuous lighting of the lamp 52 indica-tes to the testing operator that the relay 7 is improperly adjusted to function in the intended manner when its Vcircuit is trayersedby maximum current and is slowly interrupted. The testto function properly under such conditions.

l Testing of alternating current relay.

VDesiring to test the alternating current supervisory .relay 6, the operator actuatesthe key`32, whereupon the key 31 is restored to normal position. Upon the actuation of this key 32, relays 40,-43, 41, v42 and 47 are .relay 47 and the winding of the relay 51 to ing operator may thereupon adjust the relay' operatedL-'The circuit over which these relays are operated may be traced from battery through the left-hand winding of relay 40, the windings of relays 43 and 41, sleeve contacts of the engaged plugs andjacks to the point 56 in the sleeve strand connected with plug 37 and from thence through contact 57 of the key 32, tip contacts of the plug 37 and the jack 9 and the windings of relays 42 and 47 to ground. It will be noted that the resistance 44 is not included in this circuit; therefore, marginal relays 43 and 47 attract their armatures, opening the normal and closing the alternate contacts. The operation of relay 43 disconnects the direct current supervisory relayA 7 from across the cord circuit A. The operation of the two relays 42 and 47 associates with the relay 6 v the artificial line which includes the bridged resistance 21. With the keyf 32 depressed and the relays operated as described, the testing operator may now depress key 34, whereupon relay 58 is operated over a circuit from battery through the left-hand winding of relay 40, windings of relays 43 and 41, sleeve contacts of the engaged plugs and jacks to the point 56, Vfrom thence through resistance 44, contact 59 of the key 32, contact 60 of the key 34, resistance 61, ring contacts of the plug 37 and the jack 9, the lower alternate contact of relay 47 and the windings of relays 58 and 62 to ground. Relay 62 is marginal and does not operate when resistances 44 and 61 are included in circuit therewith.

The operation of relay 58 connects the source of alternating current 16 in circuit with the relay 6 and the associated artificial line. This circuit may be traced from the source of ringingcurrent 16 through the lamp 63, contact of relay 58, series resistances 18 and 17 of the artificial line, upper alternate contact of relay 47, upper contact of relay 42, tip contacts of the jack 10 and the plug 4, contact of relay 41, upper normal contacts of splitting keys 64 and 65, winding of relay 6, condenser 66, lower normal contacts of the splitting keys 65 and 64, ring contacts of the plug 4 and the jack 10, lower contact of relay 42, middle alternate contact of relay 47 and series resistances 19 and 20 of the artificial line to ground. If relay 6 is properly adjusted it will not operate. However, ifv this relay 6 operates, the energizing circuit of the relay 24 will be opened and this relay 24 will release, establishing a circuit for the supervisory lamp 25 and the relay 26, which may be traced from battery through the contact of relay 40, the lamp 25 and the winding of relay 26 in parallel, contact of relay 24 and the normal contact of listening key 67 to ground. Relay 26 in operating establishes a locking circuit for itself through its own contact, whereupon the lamp 25 remains lighted. Noting that the lamp 25 lights, the testing operator knows that the relay 6 is not properly adjusted. The key 34 may be allowed to assume its normal position to disconnect ringing current from the relay 6 while this relay is being adjusted. After making the proper adjustments the key 34'is again depressed, whereupon the relay 6 does not respond to the ringing current and the lamp 25 is not lighted. It is to be understood, of course, that the relay 6 remains operated only so long as the key 34 is depressed. When this relay is d'energized upon the release of the key 34, the circuit of relay 24 is again established. Before proceeding to test the relay 6 under maximum ringing current conditions, listening 'key 67 is momentarily actuated to open the locking circuit of relay 26, permitting its restoration to normal condition and the effacement of the lamp 25. The testing operator may then proceed to test relay 6. This is done by actuating the key 33, whereupon the key 32 is restored to normal position. Upon the actuation of the key l 33, relays 40, 43, 41, 42 and 47 operate over the previously traced circuit, the contact 68 of the key 33, instead of the contact 57 of the key 32, being included therein. The depression of key 34 then causes the operation of relays 58 and 62 over a circuit from battery through the left-hand winding of relay 40, the windings of the relays 43 and 41, sleeve` contacts of the engaged plugs and jack'sto the point 56, from thence through contact 69 of the key 33, contact 7 Oof the key 34, ring contacts of the plug 37 and the jack 9, lower alternate contact of relay 47, and the windings of relays 58 and 62 to ground.

The operation of relay 58 connects the source of ringing current in circuit as before, while the operation of relay 62 removes the short circuit from about the resistance 22, thereby including this resistance in the bridge of the artificial line to alter the electrical condition of the artificial line, thereby to provide maximum ringing current for relay 6. lf relay 6 is properly adjusted relay 24 releases, whereupon relay 26 locks up and maintains the lamp 25 lighted. If not properly adjusted, the lamp 25 will not be lighted. The testing operator mayy thereupon adjust the relay 6 until it responds properly to the maximum ringing current.

What is claimed is:

1. In a testing system, a testing circuit, i'

sources of intermittent currents and alteriis nating current, a direct current and an alterj nating current relay connected with the testing circuit, a circuit controlling device comprising a plurality of keys associated with the testing circuit, a first relay responsive to the actuation of one of the keys to connect one of the sources of intermittent current in circuit with the direct current relay, a secj,

ond relay responsive to the actuation of a Vso second one of the keys and cooperating with the first relay to connect another of the sources of intermittent current in circuit with the direct current relay, an artificial line, a third relay controlling 'the association of the artilicial line with the alternating current relay, and a fourth relay responsive to the actuation of a third one of the keys to connect the source of alternating current in circuit with the alternating current Yrelay and the artificial line.

2. In a testing system, ya testing circuit, sources of intermittent currents and alternating current, a direct current and an alternating current relay connected with thetesting circuit, avcircuit controlling device coinprising a plurality of keys associated with the testing circuit, a first relay responsive to the actuation of one of the keys to` connect one of the sources of intermittent current in circuit with the direct current relay, a second relay responsive to the actuation of a second one of the keys and cooperating With the first relay to connect another of the sources of intermittent current inV circuit With the direct current relay, an artificial line, a third relay controlling` the association of the artificial line With the alternating current relay, a. fourth relay responsive to the actuation of a thirdone of the keys to connect the source of alternating current in circuit with the alternating current relay and the artificial line, and a relay responsive to the actuation of a fourth one of the keys When the third key is actuated to alter the electrical characteristics of the artificial line.

3. In a testing system, a testing circuit, sources of intermittent currents and alternating current, a direct current and an alternating current relay connected With the testing circuit, a circuit controlling device comprising a plurality of keys associated With the testing circuit, a first relay responsive to the actuation of one of the keys to connect one of the sources of intermittent current in circuit With the direct current relay, a second relay responsive to the actuation of a second one of the keys and coperating With the first relay to connect anotherof the sources of intermittent current in circuit With the direct current relay, an artificial line, a third relay responsive to the actuation of a third one of the keys and cooperating with the first relay When energized to associate the artificial line with the alternating current relay, and a fourth relay energized upon the actuation of a fourth one of the keys While the first and third relays are energized to connect the source of alternating current in circuit With the alternating current relay and vthe artificial line.

4L. In a testing system, a testing circuit, sources of intermittent currents and alternating current, a direct current and an alternating current relay connected With the testing circuit, a circuit controlling device comprising a plurality of keys associated with the testing circuit, a first relay responsive to the actuation of one of the keys-.to connect one of the sources of interniittentrcurrent in circuit with the direct current relay, a second relay responsive to the actuation of a second one of the keys and coperating With the first relay to connect another of the sources of intermittent current in circuit with the direct current relay, an artificial line, a third relay responsive tothe actuationofa third one of the keys and cooperating With the first relay when energized to associate the artificial line with the alternating current relay, a fourth relay adapted When energized to connect thesource of alternating current incircuit With the alternating-current relay and the artificial line, an energizing circuit .for the fourth relay established upon the actuation of a fourth one of the keys, and a marginal relay for the energizing circuit operating upon the actuation of the fourth key-While a fifth one of the keys is actuated to alter the electrical characteristics of the artificial line. v i y 5. Infra testing' system, a testing circuit, sources of intermittent currents and alternating current, direct current and an alternating current relay connected With the testing circuit, a circuit controlling device coinprising a plurality of keys associated With the testing circuit, a first relay' responsive to the actuation of one of the keys to connect one of the sources of intermittent current in circuit With the direct current relay, a second relay responsive to the actuation of a second one of the keys and'coperating with the first relay to connect another. of the'sources of intermittent current in circuit With the direct current relay, an artiv iicial line, a third relay responsive to the actuation of a third one of the keys'and cooperating With thefirst relay when enervgized y to associate the artificial line with the alternating current relay, afourth relay vadapted When energized to connect the Source of alternating current in circuit with the alternating Vcurrent relay and the artificial line, and an energizing circuit for the foirth relay including a contact of the third re ay.

6.'In a testing system, a testing circuit, a source of alternating current, an alternating current relay connected with the testing circuit, a circuit controlling device comprising a plurality of keys associated With the testing circuit, an artificial'line, a first relay adapted When energizedv upon` the actuation of one of the keys to control the association of the Vartificial line With the alternating current relay, a second relay adapted When energized to connect the source of alternating current in circuit With the alternating current relay and the artirelay, a second relay adapted When ener' gized to connect the source of alternating current in circuit With the alternating cur-' rent relay and the artificial line, and an energizing circuit Jfor the second relay including contacts of both actuated keys.

8. In a testing system, a testing circuit, a source of alternating current. an alternating current relay connected With the testing circuit, a circuit controlling device cornnrising a pluralty of keys associated With the testing circuit, an artificial line, a first relay aclanted when energized upon the actuation of one of the keys to control the association of the artificial line with the alternating current relay, a second relay adapted when energized to connect the source of alternating current in circuit with the alternating current relay and the artificial line. an energizing circuit for tbe second relay established unon the actuation of' a second one of the keys and including an engaged Contact of the energized first relay, and a marginal relay in the energizing cir cuit of the second relay operating upon Copies of this patent may be obtained for the actuation of a third one of the keys to alter the electrical characteristics of the artificial line.

9. In a testing system, a testing circuit, a source of alternating current, an alternating current relay connected With the testing circuit, a circuit controlling device comprising a plurality of keys associated With the testing circuit, an artificial line, a first relay adapted when energized upon the actuation of one of the keys to control the association of the artificial line with the alternating current relay, a second relay adapted When energized to connect the source of alternating current in circuit With the alternating current relay and the artificial line. and an energizing circuit for tbe second relay jointly controlled by the first relay and a second one of the keys.

10. In a testing system, a testing circuit, a source of alternating current, an alternating current relay connected with the testing circuit. a circuit controlling deyice cornprising a plurality of keys associated with the testing circuit, an articial line. a first relay adapted when energized upon the actuation of one of the relays to control the association of the artificial line with the alternating current relay, a second relay adapted when energized to connect the source of alternating current in circuit with the alternating current relay and the artificial line, and an energizing circuit for the second relay controlled by the first relay and two of the keys.

In Witness whereof I hereunto subscribe my name this 21st day of February A. D.,

LOUIS A. MORTIMER.

ve cents each, by addressing the Commissioner of Patents,

Washington, D. C.

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