Патент USA US2406382код для вставки
‘Aug. 27, 1946. W. M. KELLOGG ' 2,406,382 INDICA‘I'ING SYSTEM Filled sept. 24, 1941 3 Sheets-Sheet 1 /CS CON TROL FREQUENCY S0 URCE FIG. / 'Y PHASE SH/FTER ’P$ I 6) PULSE aslvejmmk ‘ SWEEP /PG GENtZMTOR IA SWEEP GEN€RATOR ‘ AMPS‘ZER GAIN 22 II “"444 ‘ CONTROL 1 a 2 1 / arm my gsauoscom 4 Y s "'0 INVENTOR W M KELLOGG BY ATTORNE)’ Aug. 27, 1946. W. M. KELLOGG - 2,406,382 INDICATING SYSTEM Filed SeptT 24, 1941 3 Sheet's—Sheet 2 SINUSOIDAL CONTROL [/4 SIGNAL RECEIVER - AMP, .- ---> INVENTOR . ‘W M KELLOGG BY M5.‘ ATTORNEYv Aug. 27, i946.) W. M. KELLOGG _ ~2,406,382 INDICATING' SYSTEM ‘ , Filed Sept. 24, 1941 e, e, 3 Sheets-Sheet 3 f V ' (i) r" do "'\~ 8/0 -' ' | \".J I r /\ \ I \\\/I \ . . l’ lQ-EXPANSIION‘ INTERVAL INVENTOR WM. KELLOGG Via/46W I ATTORNEY 2,406,382 Patented Aug. 27, 1946 UNITED STATES PATENT 'OFFICE 2,406,382 INDICATING SYSTEM William M. Kellogg, Morristown, N. J., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York 7 Application September/'24, 1941, Serial No. 412,099 1 Claim. (Cl. 315-24) 1 This invention relates to an indicating system and particularly to an indicating system employ ing a cathode ray tube. It is well known in the art to employ a cathode ray tube as a timing device to indicate the time intervals between a particular sequence of sig nals. In such systems, the cathode ray beam gen erated in the tube is de?ected by means of a varying voltage applied to' one set of de?ection elements so that it sweeps at a known rate over a predetermined path on a screen or target to . provide a linear time scale or axis and the signals are applied to another set of de?ection elements in such manner as to cause transverse de?ections 2 The various features and objects of the inven tion will be better understood from the follow ing detailed description when read in conjunc tion with the accompanying drawings in which: Fig. 1 shows a block diagram of one system in accordance with the invention; Fig. 2 shows schematically a more detailed ar rangement of a system embodying the invention; and, ' r ' Fig. 3 shows curves which illustrate the indi vidual and combined performance of the com ponent elements of the system of Fig. 2. In the arrangement of Fig. 1, the conventional sweep generator A produces a saw-tooth voltage of the beam from its normal path. The disposi 15 output wave, such as indicated on the ?gure by the curve just below generator A, when it is ex tion of the latter de?ections along the normal cited by the sinusoidal voltage 8A of given fre path as displayed on the screen indicates the time quency applied to its input from the output of the intervals existing between the signals. control wave source CS. The saw-tooth voltage In order‘ that individual signals or restricted output of generator A is applied to the input portions of the time scale of the cathode ray 20 (sweep de?ection elements) of the cathode ray tube indicator tube may be closely observed, it oscilloscope 0. If this sweep alone is applied to is necessary in general to expand the scale beyond the oscilloscope O, the cathode ray beam pro the available range of the screen. As a result of duced by the latter would progress uniformly such sweep expansion, much of the total sweep from left to right across the oscilloscope screen range would be lost from View. during the time interval H to 12 at a rate estab An object of the invention is to expand a por lished by the shape of the line Il-l2 in the ap tion of the timing scale of an indicating circuit plied saw-tooth wave. In order to increase this employing a cathode ray indicator tube. A more rate by the usual method, it would be necessary speci?c object is to magnify or enlarge any de sired restricted portion of the signal pattern as ' 80 to increase the amplitude Ill-l I, and as a re sult, the amplitude of the sweep would be carried viewed on the screen of a cathode ray indicator beyond the capacity of the oscilloscope screen tube while maintaining the total sweep range of to reproduce it. the cathode ray beam within the ?eld of view of In accordance with the invention, an increase the screen, thus obtaining an e?ect analogous in the rate of the sweep over a portion of its to that obtained by applying an optical lens to 35 range without changing the total sweep range is a limited segment of the scale of a slide rule. obtained by applying to the input (sweep de?ec These objects are attained in accordance with tion elements) of the oscilloscope O, the output ‘one modi?cation of the invention by applying the of an auxiliary sweep generator B, synchronized combined output of two synchronized sweep (saw with the ?rst generator, producing a saw-tooth tooth) wave generators to the sweep de?ection 40 wave of a particular characteristic. As indicated elements of a cathode ray oscilloscope, one oi by the curve below the generator B, the latter which is the usual linear full scale generator saw-tooth wave may have a positive slope from which drives the cathode ray beam from left to 2|! to 2i and a negative slope from 2| to 22, the right across the screen, and the other having a left-to-right component of only short duration 45 positive slope from 20 to 2| being steeper than as compared with the ?rst generator. The re stricted expansion or lens effect on the horizontal scale is obtained during the interval of additive e?ect of the two generators. The particular por that from H to I 2 in the output wave of gen erator A. The output wave of the sweep gener ator B is transmitted through a suitable ampli ?er AM with an associated gain control for ad tion of the sweep pattern to. which this lens effect 50 justing the amount of expansion, before applying it to the oscilloscope sweep de?ection elements. The combination of the output waves of the two ing the relative phase of the two sweep gener generators which are applied to the oscilloscope ators, this control being analogous to that ob O is shown by the lower curve of Fig. 1, the tained by moving an optical lens along the scale 65 chosen phase relationship between the two sweep of a slide rule. ‘ ‘is applied may be controlled by suitably adjust 2,406,382 3 generators being such as to provide a 180 de grees phase difference. Thus, it will be observed that the positive interval I to 4 in the combina tion wave is composed of intervals l-Z and 3-4 of less slope than the ll-IZ slope of the posi tive interval of the output wave of generator A and 2—3 of greater slope than ll—|2. The re sult is that the interval 2—3 is expanded and signals occurring during this time interval occu py a magni?ed portion of the sweep trace of os cilloscope O. The remaining intervals I-2 and 3-4 are compressed to the extent that 2—3' is expanded so that the full scale de?ection of the sweep remains constant. y, _ The time interval 20—2| of the expansion pro vided by sweep generator 13 is controlled by the shape of the distorted voltage operating pulse produced by the pulse generator PG from the. sinusoidal voltage wave eB applied from the source 4 resistances l1, l8 in the control grid-cathode cir cuit of tubes V1 and V4, respectively, these tubes are over-driven by the large grid signal inputs e1 and as, respectively, so that the signals in the plate-cathode circuits of these tubes approxi mate wave signals, as shown by e; of Fig. 3 (b) ' and es of Fig. 3 (c) , respectively. The coupling condenser l9 between the plate of tube V1 and the control grid of tube V2, and the coupling condenser 23 between the plate of tube V4 and the control grid of tube V5 are con trolling impedances as compared with the asso ciated grid coupling resistances 24, 25 and 26, 21, respectively, and therefore cause the grid signal voltages es and es applied to tubes V2 and V5, to be the di?erentials of the plate signal voltages ex. and c4 of tubes V1 and V4, respectively. The former signal voltages, therefore, have pulse char acteristics. The voltages es and 6e are shown in CS to the input of the latter through the phase 20 Fig. 3 (c) and Fig. 3 (b), respectively. The shifter PS. By suitable design of pulse generator voltage es is required only to ?re the sweep gen PG, the expansion interval may be made large, erator vs with precision. The voltage e5’ applied or it may be made small so that a very short to the control grid of tube V2 controls the interval time interval is made to cover the full scale of the oscilloscope O. The phase shifter PS is pro 25 of sweep expansion. The pulse characteristics of 65 are determined by the amplitude» of the control vided for those applications in which it is re grid voltage driving tube V1. The greater this quired to shift the expansion interval along the pulse duration, the longer the interval of, sweep entire sweep interval. a expansion. The tube V2 is biased below cut-off _ Fig. 2 shows in more detail circuits which may so that‘ only the positive pulse intervals of the be used to provide the restricted sweep expansion applied voltage as will affect the plate current of in accordance with the invention. In the system V2. This results in the discharge of condenser of Fig. 2, the oscilloscope comprises a cathode 28 during the positive grid intervals and its re~ ray tube 6 in which are disposed the usual cath charge through resistance 30 during the inter ode ray beam producing and control apparatus 1, a pair of vertical de?ection plates 8, a pair of 35 vals between positive grid pulses. The resulting saw-tooth voltage-developed across resistance 30 horizontal de?ection plates 9' and a ?uorescent is shown as 67 in Fig. 3 (d). The tube V3 am screen l3. The output ofva receiver M for de pli?es the portion of this voltage appearing in tecting the signals to be displayed on the screen resistance 3| connected across condensers '28 and of the oscilloscope is connected through the sig nal ampli?er [5 across the vertical de?ection 40 29." The output of V3 and hence the degree of mid-scale expansion may be controlled by ad plates 8, causing the vertical de?ections of the justment of the variable resistance 32 in the plate cathode ray beam proportional to the varying po cathode circuit of that tube. The output voltage tentials of the received signals, along the timing of tube V3 is shown as em in Fig. 3 (f) . base line formed by the horizontal sweep of the Similarly, the tube V5 will operate in response to beam across the screen under control of the sweep 45 the pulse wave es applied to its control grid to voltage applied to the- horizontal de?ection cause the discharge of condenser‘ 33 during the plates 9. positive grid intervals and to recharge that con In the arrangement of Fig. 2, the resistance denser slowly through resistance 34 between capacity coupled three-electrode vacuum tubes The resulting saw-tooth voltage is shown vV1, V2 and V3 corresponding in function to the 50 pulses. as ea in Fig. 3 (e) . pulse generator PG, the sweep generator B and The saw-tooth voltage output e10 developed the ampli?er AM with its associated gain con by tube V5 and the expansion sweep voltage 68 trol, respectively, in the system of Fig. 1, are em produced by tube V3 are combined in the control ployed to produce the auxiliary sweep B of the grid-cathode circuit of sweep ampli?er tube V6 cathode ray beam for expansion, and the resist 55 to form voltage (211 as shown in Fig. 3 (g), which 4 ance-capacity coupled three-electrode vacuum is ampli?ed by ampli?er V6 and applied across tubes V4 and V5, corresponding in combined func the horizontal de?ection plates 9 of the cath~ tion to the sweep generator A in the system of ode ray tube 6. The expansion interval occurs Fig. 1, are employed to produce the main full at mid-scale of the sweep voltage. As noted scale sweep A of the beam. With this arrange 60 above, it is under control of the variable cou ment, the expansion interval is placed at mid pling resistance 32 in the plate circuit of tube ‘scale of the main sweep by operating the tubes Va. The dotted curves em’ in Fig. 3 (f) and en’ V1 and V4 at 180 degree phase relationship by in Fig. 3 (9) show the effect of increasing this connecting them in push-pull with respect to the so that the expanded segment oc applied constant frequency sinusoidal control 65 resistance cupies the full scale of the oscilloscope. The wave from source CS, and the phase'shifter PS of the system Fig. l is omitted. The operation of the system of Fig. 2 will be explained by reference to the curves of Fig. 3. Fig. 3 (a) shows the sinusoidal constant fre quency‘voltages (21 and c2 with 180 degrees phase di?erence between them respectively applied to the control grid-cathode circuits of the tubes V1 and. V4 from the control wave source CS through input transformer it. Because of the large series . lower the setting of resistance 32, the more nearly the‘ sweep voltage approaches a conven tional saw-tooth sweep which‘ will cause the cathode ray‘ beam in tube 6 to move at a uni form rate from left 'to right over the screen l3. As the amount of injected expansion is in creased the faster the beam travels at mid-scale and the slower at the other portions of the screen. The 'eifect of the combination is‘ a center expansion and a corresponding‘ end com 2,406,382 5 6 pression of the oscilloscope signal pattern. scale and a corresponding compression of the ‘ The whole signal pattern is thus kept in view as remaining portion so as to maintain the total sweep range within the ?eld of View of said the center is expanded for close observation of part of the pattern. It is thus possible to monitor the full sweep range, even though, say 5 per cent of the scale is expanded to occupy 50 per cent of the full de?ection. By the use of a suitable phase shifter, such as shown in the alternative arrangement of Fig. 1 to pro vide various adjustments of the phase rela tions of the main sweep generator and the auxiliary sweep generator, the expansion may be applied to any desired portion of the sweep screen and means for controlling the relative phase of the outputs of said generators to se lect the portion of the scale to be ampli?ed, said one generator comprising an ampli?er having a plurality of resistance-condenser coupled vacu um tube stages, the second stage of which is 10 biased below cut-o?, means to apply a sinu soidal voltage input to said ampli?er of sum cient amplitude to overload the ?rst stage thereby producing a square-shaped voltage out put for that stage, the resistance-condenser pattern. Various other modi?cations of the circuits 15 coupling between the ?rst two ampli?er stages being proportioned so that the voltage input to illustrated and described which are within the the biased second stage is the di?erential of the spirit and scope of the invention will be ap voltage output of said first stage, thus producing parent to persons skilled in the art. a pulse output for said second stage which is What is claimed is: unaifected by the positive portions of the input In combination with a cathode ray tube sig voltage thereto, the condenser in the output nal indicator including cathode ray beam pro coupling of said second stage discharging dur ducing and de?ecting means and an indicating ing the positive input intervals and recharging screen, two saw-tooth wave generators for con through the resistance thereof during the in trolling said deflecting means to sweep the cathode ray beam back and forth across said 25 tervals between positive inputs, the gain of said ampli?er being adjusted to provide the desired screen to provide a time scale thereon, one 01” degree of scale expansion and the amplitude of said generators producing a saw-tooth wave, the the sinusoidal voltage input thereto being se rising portions of which are of relatively short lected to control the pulse duration of the duration compared with those produced by the other generator, such that the combined action 30 ampli?er output applied to said de?ecting of both generators on said de?ecting means re sults in an expansion of a portion of said time means and thusthe interval of scale expansion. WILLIAM M. KELLOGG.