Historical Document · 1971
US 3,600,525 Test Set for Strowger Switches
Portable Strowger switch test set design; comparison for the 26A.
Historical Document · 1971
Portable Strowger switch test set design; comparison for the 26A.
ilnited States Patent [72] [111 3,600,525 [21] [22] Inventors Jim C. Garrett; _ Robert H. Johnson, both of 5060 Salt Lake Avenue, Huntington Park, Calif. 90255 Appl. No. ‘64,132 Filed July 31, 1970 [45] Patented 625,830 1,334,767 1,482,891 5/1899 3/1920 2/1924 .. 4/1946 Obermaier ................. .. 9/1947 Simpson ..................... .. 2,397,975 2,426,712 Aug. 17, 1971 Continuation of application Ser. No. 2,597,188 5/1952 Rozett .... .. 2,680161 6/ 1954 Clement... ‘ 654,871, July 20, 1967, now abandoned. ‘ 324/149 179/175.23 317/120 324/156 324/ 156 .. 324/149 179/175.2 2,797,268 6/1957 Reagan . . . . . . . . . . . . . .. 3,027,429 '3/1962 Eklov . . . . . . . . . . . . . . . .. 179/ 175.23 179/1 3,265,820 8/1966 Edwards ..................... .. 179/175.21 Primary Examiner- Kathleen H. Claffy AS51810"! Exammer— DaVld 5 Claims, 3 Drawing Figs. [52] [51 ] U.S.Cl ...................................................... .. 179/175.21 lnt. CL‘. .............................................. .; ..... .. H04m 3/26 [50] Fieldol Search .......................................... .. [56] 179/175, ABSTRACT: A test set particula?y for equipment such as 175.2, 175.2 A, 175.23, 175.21; 317/107, 120; PBX, CD0 and large telephone central offices, and compris ‘ ing a hand-portable and compact boxlikc, case-type unit in which is incorporated means to test timing and pulsing, 324/114’ 149' I56 References Cited UNITED STATES PATENTS 617,418 l/1899 Strowger two-motion switch “A" relay current ?ow, polarity across the lines, and ampli?ed push-to-talk circuits of such Hanchett et a1. .... ..'. .... .. 324/156 equipment. 71 K59 57 1 .7 l % 48) RELEASE BREAK l___ 58/ ADJ. | 36/ h , 53 , ' TIME ‘ " Stewart A"omey'“Hyma" Jackman TRAgfiligioR i L - 50 49 // iI "W --J ,’ ' SWITCH {swncH-_o 61 —1" I 97 62 / l I,’ 46:” a ' a 33 A RELAY‘CUQRENT - , 29 Fww ‘ 65 " RELAY'_° ‘mini/6"‘o L.‘ TTEST JIQCK /’ 41) MLM‘C-D'I 3,9 I 385% l DELAY/J2 i TEsT 59 34 - 4e / GENERATOR “41.? i 1 RELAY 3 R01‘. /___.-_.__...|__.__ / | 64 PULSE /47 5 .54) I ‘60 ‘I RELAY "115. F331 IMPED. AUDIO‘ ‘t Pig-iii? AMP’- J AREW :1 POL, 9 557'mm. , 43 ‘ P-? j Aumo @AUDIO PM)’; .0 1 r, ‘10". 5712,l | ‘1% : . 42.43 1 i ‘I L—-——-~--~----~-u,? '44 i I I - - ’ J | ' l ‘ : I Z6 I /‘. FUNCTION 5W1TCH | - i -‘—-~-----— ~ 1 am. JACK ~33‘ g 3,600,525 1 2 from which the same may be removed toconiie'ct the ‘checking y > I _ TEST FOR STRQWGER SWITCHES and testing means 6 to a power source and to the various com ‘ . ‘ CROSS-REFERENCES TO RELATED APPLICATIONS ponentsof the equipment to be cheekedi'and tested for the This is a continuation of application SenNo. 654,87l,?led operating condition thereof. - ‘ _ The checking and testing mechanism 6 is shown as compris ing, generally, a battery jack 25; a mode‘ or function switch 26 ‘connected to said jack; a test jacklllTalso connected to the function switch, the function switch, being of the stacked July 20 1967, now abandoned ' BACKGROUND OF THE lNVENTldN For testing the various'telephone systems, as above, to ' locate malfunction and pinpoint troubles, especially after a wafer type having 12 positions in this case, is connected to pattern of the same has been developed, in the past entailed the use of large, eitpensivev and difficult-to-transport ap Q'fA" relay current flow components. 28 (A-Soak), “B” and ‘,‘C" relay timing components 29, an audio pickup transformer paratus. Setup time for such equipment is usually lengthy and, therefore, undesirable economically. Also, particularly high 30, a loop-pulsing component 31, and a leak-pulsing com ponent 32; the knob 33 Fig. 2 being provided for adjusting the skill is’ required both for setupand for carrying out the dif 15 position of the function switch 26 with relation to the above listed components 28 to 32 and as indicated by the indicia re ferent tests. Moreover, such three-part ‘old type of testing‘ lated to said knob; a digit switch 34 controlled by a knob 35 equipment required a separate ‘telephone handset for monitor which selects the number of pulses supplied to the Strowger In contradistinction to the great skill needed for testing ‘ two-motion switch of the apparatus being tested; a rotary telephone equipment, an object of this invention is to provide 20 switch 36 having its pulsing functions controlled by the knob a small, compact and lightweight test set that may be em 35 according to the control of the digit switch 34 by said knob; ployed even by inexperienced switch men to test the operation the transformer 30 being series-connected to the straight light of step-by~step equipment embodying Strowger switches 37 for designation correct polarity across the tip and ring of ing the tests that were carried out. under simulated operating conditions. ' Anotherobject of the invention is to provide a test set, as above characterized, that eliminates time-consuming setup and, in larger central offices provided with built-in apparatus, ‘the line and a reverse light 38 for designating a reverse indica tion'thereof; an audio relay 39 connected to a speaker and a microphone and connected in series with both said lights; a solid-state audio ‘ampli?er 40 for and connected to said relay complements the same and is particularly effective in pin 394, an impedahce-matching transformer 41 connected to the pointing troubles after such built-in apparatus has developed a 30 audio relay 59; a line‘ 42 from the network’ of each pulsing component 31 and 32, according to the different resistance This invention also has for its objects to provide such means values thereof, connects the same to the, contacts of a release that arerpositive in operation, convenient in use, easily in relay 4-3, which is energized by one key 44 that is operated by stalled in a working position and easily disconnected pattern. , a therefrom, economical of manufacturer,‘ relatively simple, and 'of general superiority and serviceability. The invention also ‘comprises novel details of construction and novel combinations and arrangements of parts, which will a release button 45; a connection 46 from the relay 43 ‘to a ‘pulse relay 47 which, through a line 48-, is connected to drive the rotary switch 36 and which, through a line 49, is con nected, to a time relay 50 and thelatterfby a line 51, to adelay more fully appear in the course of the following description, relay ‘52; a second releasekey 53, controlled by said button describes, one embodiment of thepresent invention, which is through the jackp25k', a PPS (pulses-per-second) switch 55, 45, when closed releases the relays S0 and‘52; a ‘transistor which is based on the accompanying drawings. However, said drawings merely show, and the following description merely 40 pulse generator 54 connected to said line 51 and to current given by way of illustration or example only. ' SUMMARY OF THE lNVENTlON (inThe practice,‘ present71/4 test set inches comprises, square and7V4> ‘generally, a inches two—part deep), ‘casethe present checking ‘and testingmechanism 6 being mounted in eomrolled by a selective knoh 56 that may be set for 10 or 12 pulses, is connected to the generator 54 and has a conductor 45 57 that extends to and electrically connects with a percent break-adjusting, preset ‘rhe'o‘stat unit: 58 which‘, in ‘turn, has an input connection 59 to the pulse relay 47', and the generator 54, through va line 60 and the contacts of the time relay 50, drives the pulse relay 47_ through line 49, the latter, in turn, one case part 7 and a ‘suitable power cord 8 and test cord 9 so driving the rotary switch 36. V being stored in the other case part 10. ' BRlEF DESCRIPTION OF THE DRAWINGS . in the drawings, like reference characters designate similar parts in the several views. FIG. 1 is a block diagram of the checking and testing mechanism of the present invention. FIG. 2 is a face view, showing the controls of said‘ mechanism. ‘ _ The A-Soak components 28 comprise a short 61 for the A‘ Soak function of said component, a variable resistor 62, con trolleo by a knob 63, for ‘the nonoperate value of a DC mil liammeter 64, and a second variable: resistor 65, controlled by a knob 66, for the operate value of the milliammet'er. A test key ‘67, controlled by a button 68,‘ connects thecom‘ ponent 28 to the meter which has a return connection, through the test jack and, therefore, to the Strowger switch ‘ , H6. 3, to a reduced scale, shows the two'part case in which 60 under test. A second test key 69, controlled by the same but‘ said mechanism is contained, as well as the power and test ‘ cords required to connect the mechanism to power and to the telephone equipmerit being tested. DESCRIPTION OF THE PREFERRED EMBODIMENT ton 6,8, closes the circuit through the delay and time relays to the solid-state pulse generator 54, the latter thereby activating the pulse relay 47. Said switches 67 and 69, while being actuated by the same 65 button, are independently closed according to the various The case 5 is a carrying case and may, if desired, be pro vided with a shoulder strap not shown or may be carried by its handle l5 attired to the case part 7. Also, u‘strup to mount the case on a support. post or ladder in handy testing position, settings of the function switch 26, under control of the knob 33. A switch 70 connects the audio relay 39 to power, and a may be separably connected, as by a laterally separable hinge A volume control 73 may be provided for the audio speakers represented by the‘grills 74. ‘ The cords 8 and 9 are plugged into the jacks 25 and ‘27, switch 7l changes the B-relay timing of the component 29 fromfa higher testing to a lower testing standard or value, a may be provided on the case part 7. The two parts 7 and [0' 70 single button 72 closing said push-to-talk feature. 16 at the bottom of‘ the case, and a trunk latch ‘or catch 17 ori the top. The part ‘10 is provided with a hinged false bottom‘ 18 that is held in place by a catch 19 so as to enclose a space 10 in respectively, with their ends clipped or otherwise electrically which the cords 8 and 9 and the harness strap are stored, and connected to the components under test. . 3,600,525 I 3 . v 4 OPERATION OF THE SET FOR VARIOUS TESTS The talk function is accomplished by pressing the button 72 - In all tests, the circuit to the Strowger telephone switch . I‘ to close the switches 70 ahd-i‘ll. This applies battery to the under test is through the terminal T of the test jack 27, to the ' ‘function switch 26, and from the ring terminalR of said test jack 27 through the" r'el'easeikey 44 to another level of the I function switch. Therefore,‘ all circuit descriptions for- the dif ferent tests will start atzthe function switch 26. _ ‘audio irelay 39, which transfers’ the microphone to the inputof the amplifier 40'and"also switches the output to'the im pedance-matching transformer 41-(8 to 1000 ohms). This matches the amperagemoutputto the 1000 ohms of the audio pickup transformer 30. The volume-adjust has no control of the talkcircuit._y,-;.... ~Y ' v H ,AeSoak TEST 'Circuit-,'from‘ the'function switch, follows the short 62 placed across the “A" relay at another level of the function switch, - \ > 1_, v .' ' > - ' g, ,i .. , _ In the following leak tests, the circuit path is from. the func 15 tion switch through the leak-pulsing component 32 and back From the function switch through variable resistor 62, a nonoperate adjust, through‘ the milliammeter 64 back to the function switch. to the function switch. The only di?'erence is whether the value of parallel capacitance and/or-resist'anc'e is 10,250 ohms paralleled by 5K ohms in series with 2 MP capacitance for the. 20 LK.A setting of knob 33; 10,250 ohms of parallel resistance for the LK.B setting; or 16K ohms of parallel resistance for the - A-OPERATE (A QPR.) TEST _ LK. 16K setting. From the function switch through variable resistor 65, an A-. . I - ' . The tests, starting with Polarity-Monitor clockwise to LK 16K, can be made in either l0—or l2-PPS; this switch only changes the resistor in the timing of the trigger circuit which Operate adjust, through said milliammeter back to the func ‘ 1 ohms, according to the setting of the knob33. ' A-NONOPERATE (‘A ND.) TEST tion switch. > In the following loop tests, the'circuit path is‘from the .func tion switch 26 through a loop- resistor of the pulsing ‘com; ponent 31 and back to the function switch. The only dif ference is whether the ‘resistance value is 1400 12000;. 350 ‘ determines the speed. , B-RELEASE TEST ‘ - The percent break is-established for leak and loop tests. Leak-60.5 percent break and loop-68.5 percent break. From the function switch 26 to PPS switch 55, to the rotary switch 36 and back to the function switch. This allows thetest This established value is met when the set is calibrated. The to be3made only in 12 PPS for correct timing of B-Release. 30 proper resistor for each is picked whenever a loop or leak function is selected or the speed is changedv while in loop'or The same holds true for C-Release and Rotary Test andfor the same reason. - . ~ leak. _ .' ,v - While the foregoing has illustrated and described what is To initiate this test, it is necessary to place the digit'switch now contemplated to be the best mode of carrying out the in 34, by means of the knob 35, to the “C" position (continued pulsing). This allows the rotary switch 36 to step continuously. 35 vention, the construction is, of course, subject to modification ln anyother position of the digit switch, a contact thereof is without departing from the spirit and scope of the invention. - grounded, depending on the setting of said switch. This Therefore, it is-not desired to restrict the invention to the par ticular form of construction illustrated and described, but to cover all modi?cations that may fall within the scope of the ground stops the output of the pulsegenerator 54 and shuts down the time relay 50 at the proper time, thereby giving the 40 appended claims. correct number of pulses ‘to the Strowger switch under test. ' . - motion switches, comprising: relays 50 and 52. The latter then activate the pulse-relay 47 which causes stepping of the rotary switch 36 the desired 45 number of steps,- thereby- continuously pulsing the Strowger switch under test. In the usual way, shorted terminals of the switch 36 give the timing values. 50 a.‘function switch means having a plurality of switch sec tions each having a wiper and a plurality of terminals adapted for velectrical connection in accordance with each individual test to be performed; b. a battery jack having tip, ring and sleeve contacts, said sleeve contact being connected to the wiper of a first one of said switch sections of said function switch means and to a'DC source when the function switch .means is in a predetermined position; From the function switch 26 to the PPS switch 55, to another level of the rotary switch and back to the function switch. Also, in 'thisposition, a ground is placed on the sleeve S of the test jack 27 for the purpose of making the switch 55 under test rotate the required number of steps ina prescribed period of time. This ground to the sleeve comes from a level of 'i c. a test jack having tip, ring and sleeve contactsfeach respectively connected to the wiper of a corresponding one of the remaining switchisections for carrying out the testing ofsaid equipmentp '. g 5 : . :: ~ '1 -. . ,I ~ -.j ,» " d. manually operable selector meanscommon to all switch sections for selecting the terminals of said function switch the function switch. means; POLARITY-AND MONITOR 60 From the function switch through the release relay‘43 through alow resistance ZOO-ohm winding of the audio pickup thereby determining which light will illuminate according to the polarity encountered.‘ ' The audio monitor portion of ‘this function is as follows: the audio is picked up through the transformer 30 and goes 70 through the audio relay 39 to the volume control represented by‘ the knob 73 where the desired [evens adjusted in a‘c'onven tional manner. The audio then goes 'to'thl‘e amplifier 40, and the output thereof to the audio relay 39v and out to the speaker , . - . 1 .. - .v , Y e. A-relay current flow means responsive to operation of said selector means for establishing current flow within predetermined limits; . means including B-relay timing means and C-relay timing transformer 30, which has a 200/1000 ohm capacity, to the polarity lights 37 and 38 and back to the switch. Said lights 65 have their diodes in backeto-back relation thereacross, connected thereto. _ l. A test set .for telephone equipment havingStrowger, two in the 12 PPS position by-means of the knob :56, and to then press the test button 68 to get the pulses of the time and delay C-RELEASE AND ROTARY TEST ' We claim: ~ _ For this test, it is also necessary to place the PPS switch 55 ‘means responsive to operation of said selector means for transmitting from said test set to said Strowg'er switch a ' continuous train of pulses at a predetermined rate; g. audio transformer means responsive to operation of said "‘ selector means for providing an audio connection with " said'equipment under test; -‘ * t ' ‘ " " v . loop-pulsing means responsive to operation of said ‘selec ‘tor means and including resistive means in circuit with said equipment under'testf > ' ' I. leakfpulsing means responsive to operation of said selec Vtor means and including paralleled resistive-capacitive means in circuit with said equipment‘unde'r test; | 3,600,525 5 6 j. a digit switch selectively movable to a plurality of posi tions each position supplying a different predetermined number of timing pulses; to said pulse relay means; ' k. a rotary pulsing switch controlled by said pulses from said digit switch; > g u. said generator being connect-ed through said contact means of said time relay to said pulse relay to thereby operate said rotary switch as said pulse relay is pulsed; ~ v. current indicating means including a test key in series I. polarity indicating light means connected to said audio transformer means for indicating straight and reversed polarity indications of said tip and ring contacts of said test jack; therewith for indicating said current ?ow associated with said A-relay current ?ow means; and w. said test key having a mechanical interconnection to said key-controlled delay relay thereby providing a circuit for rn. audio signal indicating means in series connection with n. key-controlled release relay means in electrical connec actuating said pulse relay means. I 2. A test set according to claim 1 in which an audio relay is serially connected to said audio transformer means and tion with said loop-pulsing means and said leak-pulsing further connected in series with said polarity indicating light means; means, said audio relay being connected to a microphone and said light means; ' I . pulse relay means connected to said release relay means 15 speaker means having an amplifying means therefor, and an - for pulsing said rotary pulsing switch; . a key-controlled time relay connected to and operated by impedance-matching transformer connected to said audio relay. said pulse relay and including contact means; 3. A test set according to claim 1 in which variable re sistance means are in serial connection with said terminals and . a delay relay connected to said time relay and including a test key in operative connection therewith; said current indicating means for establishing nonoperate and operate current values as indicated by said current indicating 4. A test set according to claim 1 in which both the test key in series with said current indicating means and said test key of r. a pulse generator connected to said DC source through said battery jack; s. a selectively operable pulses-per-second switch con nected to said generator to select the pulse repetition rate of said generator; 25 said delay relay are provided with a common actuator. 5. A test set according to claim 2 in which a switch connects said audio relay to said battery jack. . a percentage-break adjusting rheostat connected to said pulses-per-second switch and having an input connection 35 45 50 55 60 65 70 75