Type 616 Nixie Tube — Reference Document

Type 616 Nixie Tube — Reference Document

SS = AN ae RU Ne : Ee S Be ee / oe SEE | . Cc O N TT E N T S Page INTRODUCTION oo cccccccccccscsssesessssssnsesessssssssssessscacsecresessssesatecesecsvessssasavasassssasaracssavasce savsesscessusesestenscaveverens 4 GUIDE TO NIXIE TUBE SELECTION AND IDENTIFICATION.....ccccccccccccccccccccosccccocess 5 ELECTRICAL AND MECHANICAL DATA MINIATURE TUBES oooiiccccccccccscscesssssccsssesececcsssverecsesssssssesssssssessessasssessesssssussssassevassssansamesseetseeceessseee. 6 STANDARD AND SUPER TUBES oouii.ccccccccccsssssssssscssssssssscsssssssessssssusevasestssatisesssiesessssttcsecessseveceessess 7 LARGE AND JUMBO TUBES .ooieccccccccccsccscsssssessssssesssssscsestsesessstuvesessitessisisesssibsessiesstssiceesssececseseccee 8 TECHNICAL MEMORANDUM ELECTRICAL CHARACTERISTICS oo. cccccccssessssssssessssesssssssecssuesssscssecserssssecessesssssecssvesssssessesensessesees 9 SUPPLY, IONIZATION, AND SUSTAINING VOLTAGES ooeccccccsccssssscscssecscssesossecccssescsssccsses 9 SERIES RESISTOR wiiiccccccccssssssssssssssssecsssvsesssccssesersuscssssessuecessssssucssssecsaseccsseccessass uassucassuvessrseasanecesese 9 PRE-BIAS oiccccccsssssssssssssssessssssessvecsssssesssscssssvessnuecssaveccssseccnveserseceesuseessusessassatsnucssssessasstuscessssasasecsasuessasecessee 10 ACCESSORIES SOCKETS, PIN STRAIGHTENERS, WIRING PLUGS, TRIXIE DRIVER MODULES ....ccccccccscsossosesesees 21 MINIATURE TUBES ooo occcccccccsssscssssssecsssssesesssucccssvasessssuecsessussssaveseessasssessavesssssussssssecssesscssaeecssseesees 22 STANDARD AND SUPER TUBES .iiioicccccscsssssssssssssssssssssvussssssssssseesssesssvssesssssasanivesssstiteeceessseeee 23 LARGE AND JUMBO TUBES woooiiiccccccccsssscssssssssssssesessssssesssssussssssesessssuvecasstuvestivecessscecseseseceesecee 25 DC/DC CONVERTER FOR ALL NIXIE TUBE TYPES oo... ccccccccccccssssssceccccccseececccsseses 25 SPECIAL CHARACTER TUBES .uiiiiiccccccscscsssssssesscssussessssssessvssesssssssssseresercsiessesssstseteeresetseseseceseees 26 NOTE: Data on Transistor Circuits contained on Pages 14 & 15 courtesy of Pacific Semiconductors, Inc. INDUSTRY'S MOST POPULAR IN-LINE READOUT DEVICE Nix! E* INDICATOR TUBES -..«..- INTRODUCTION ANOTHER ELECTRONIC CONTRIBUTION BY Burroughs corporation ELECTRONIC COMPONENTS OIVISION PLAINFIELD, NEW GFRBLY NIXIE tubes are all-electronic, gas filled, cold cathode indicators. They consist of a common anode and ten individual metallic cathodes, each of which is formed to the shape of numerals (0-9), alphabetical characters, or special symbols. Their simplicity of operation makes NIXIE tubes ideal for the con- version of electro-mechanical or electronics signals directly to readable characters. Application of a negative voltage to the selected character with respect to the common anode makes the character the cathode of a simple gas discharge diode. Only the selected character is visible in the common viewing area because the visual glow discharge is con- siderably larger than its metallic source. NIXIE tubes are unusually efficient electronic-to-visual converters since all of their electrical energy is converted into a neon glow of relatively narrow optical band width. The eye acts as a natural filter and distinguishes this glow in high ambient light. Typical features which have established NIXIE tubes as the readout standard of the electronic industry are: 1. All-electronic design provides: a. Minimum power requirements b. High speed of operation 2. Smallest volume and lightest weight make simple and reliable pack- aging possible. 3. NIXIE tubes are lowest in cost — both to buy and operate. 4, Human engineered character design eliminates confusing segments or dot matrix patterns. 5. Best readability for characteristic size at any distance — any view- ing angle: 6. Temperature, shock, and vibration characteristics qualify the tube for military use. 7. Simple decimal inputs eliminate decoding or segment selection circuitry. 8. NIXIE Tubes offer longest life and greatest reliability of any readout device. This last feature, the combination of life and reliability, requires further explanation, since it is probably the most important reason for the NIXIE tube’s outstanding popularity. In September 1958, after two years of development and production of “regular” standard NIXIE tube types, a new series of tubes was announced. Called “Ultra Long Life” NIXIE tubes, these devices ex- hibited greatly increased life expectancy. On the basis of accelerated tests, a life of 20,000 hours per cathode or 200,000 hours for a complete 10 cathode tube was predicted. The 200,000 hour figure was based upon an assumption of uniform use of each of the characters within the tube. To confirm these estimates, 50 Ultra Long Life Standard NIXIJE tubes (Type 8037 (B5031) were placed on life test on September 9, 1958. Ten tubes were operated dynamically (sequential changing of cathodes at a 2 cps rate), while the remaining 40 tubes were subjected to “static” life (continuous display of the same character). This is the most severe life condition possible. (4 tubes displayed the numeral Zero, 4 tubes the numeral One, etc.) On December 8, 1958, a second group of 50 tubes joined the continuing life test and were operated in the same manner. Progress of the life tests as of January 1, 1962, 29,200 hours later, indicates that of the first 50 tubes, 49 are still operating. One tube developed an intermittent open connection caused by a poor weld after 21,600 hours of continuous “static” operation. Examination of the cath- ode surface of the numeral which had been lighted showed it to be in excellent condition and capable of many more thousands of hours of use. The second group of 50 tubes have passed the 26,800 hour mark without a single failure of any type. Based upon the results of tests to date, it is apparent that the original life predication of 20,000 hours (static) and 200,000 hours (dynamic) were conservative, since visual examination of the tubes undergoing test indicates that the individual cathode life will be on the order of 35,000 to 50,000 hours. Assuming that “dynamic” life under actual field operating conditions may provide a less than equal distribution of usage among the 10 characters of the tube, a realistic “dynamic” life can be predicated as being between 200,000 ‘and 500,000 hours. These figures indicate that Ultra Long Life NIXIE tubes can be ex- pected to outlast the equipment in which they will be used. This life and reliability, combined with the advantages of low cost, low power, best readability, small size and weight, high speed, rugged construction, and simplicity of operation offer the design engineer the ultimate in readout performance in a single device — the NIXIE Indi- cator Tube. GUIDE TO NIXIE TUBE SELECTION AND IDENTIFICATION NIXIE tubes are available in 5 basic sizes, each of which is designed to meet a specific viewing distance requirement. The following tabulation is designed to serve as a guide to the selection of the proper tube size for your application. TUBE GROUP MINIATURE STANDARD SUPER LARGE JUMBO NUMERAL SIZE HEIGHT 0.3” 0.6” 0.8” 1,375” 2.0” MAXIMUM VIEWING 11-14 feet 27-30 feet 37-38 feet 60-65 feet 90-100 feet DISTANCE* FOR DETAILED SEECIFICATIONS Page 6 Page 7 Page 7 Page 8 Page 8 *Under normal ambient lighting. Figures represent results of readability tests conducted under controfled conditions, with range of values resulting from variations in sight of viewers. Within each tube group there are types which possess various combina- tions of electrical and mechanical features, e.g. Ultra Long Life, Regular Life, Low Voltage, Wide Viewing Angle (and combinations thereof). Com- plete specifications on the various types which are available within a par- ticular tube group will be found on the pages noted above. For ease of identification, Ultra Long Life types are printed in blue. Tube identification by type number: Each NIXIE tube, when originally produced, is assigned a type number which consists of 4-5 digits preceded by the letter B, e. g. B4081, B5031, B6091, B7094, B8091, BSOII7, etc. As these tubes are registered with the Electronic Industries Association, ELA numbers are assigned. As examples, the original B5031 Standard Nixie tube has become the type 8037, and the Miniature Type B4032 has be- come the 7977. Wherever possible in this catalog both numbers are shown for ease of identification. MINIATURE TUBES ELECTRICAL DATA B4d08i Wide 7977 (B4032) 7009 B4021 Viewing Angle Long Life Regular Low Voltage Absolute Ratings Ionization Voltage (Maximum) 170 Vdc 170 Vde 170 Vde 120 Vde Supply Voltage (Minimum) - See (Note 2) 170 Vde 170 Vde 170 Vde 120 Vdc Cathode Current (Peak) See (Note 1) 2.0 ma 1.5 ma 2.0 ma 2.0 ma Test Conditions (See Basic Circuit, Fig. 1) Supply Voltage 170 Vdc 170 Vde 170 Vdc 120 Vdc Series Resistor 68 K IDK 68 K 20K Cathode Current: (Minimum) 0.7 ma 0.7 ma 0.7 ma 0.7 ma (Maximum) 1.4ma 1.4 ma 1.2 ma 1.4 ma Recommended Operating Conditions (DC), _. (See Basic Circuit, Fig. 1) Supply Voltage (E) 170V]250V[300V" | 1/0 2250V BOOV 11 70V [250V1300V 120V Series Resistor (R) 68K} 150K]200K { 15K] 9IK{ISOK | 68K1150K {200K 20K Note I. Due to life considerations only long life NEXIE tubes are recommended for pulsed operation. Note 2. The minimum supply voltage should be as stated for each tube type. However, the use of the highest voltage available, with the appropriate series resistor to maintain cathode current within the specified limits, is recommended. MECHANICAL DATA All Types Outline Drawing * Figures 2 or 3 : > t+ Sockets Page 22 Wiring Plugs Not Applicable Pin Straighteners Page 22 Pin Connections Figure 4 *All Miniature Type NIXIE tubes are available in both Short and Long Lead versions, Short Lead versions are shown in figure 2 and 3. The . . . . Long Lead tubes have 1.400” leads and are designed for direct solder con- Fig. 1 — Basic Circuit nection to circuit boards. The tubes can be ordered by applying the suffix L to the regular tube type number (Ex: 7977L. B4021L, 7009L, B4081L.) PIN CONNECTIONS .925 MAX. 840 MIN. 310 .650 DIA. | MAX. MAX. " .250 MAX, } PIN NO CHARACTER a .032 ' gant MAX. ge Be. 1 Numeral 1 Fig. 2 — Outline Drawing for all Miniature Tubes except Type 7977 2— Numeral 2 3— Numeral 3 4— Numeral 4 5— Numeral 5 940 MAX. ! BOTTOM VIEW 6 — Numeral 6 7840 MIN. 310 .680 OIA. 7— Numeral 7 | MAX. MAX. For P, sewing 8 — Numeral 8 or Proper viewing — 9 Numeral 9 Pins 1 and 7 should be 250 MAX, vertically aligned with 10 — Numeral 10 BRE BC, Fig. 3 — Outline Drawing for Type 7977 Tubes Fig. 4 — Pin Connections for Miniature Tubes ENVIRONMENTAL DATA coniact Applications Department for specific data on individual tube types — See Page 20 for general information STANDARD AND SUPER TUBES ELECTRICAL DATA STANDARD SUPER BSO92 Boag! 6844A 8037 (B5031) Long Life 7153 B6OR3 Lone Life Regular Long Life Wide Angle Regular Long Life Wide Angle Absolute Ratings Ionization Voltage (Maximum) 170 Vde 170 Vde 170 Vde 250 Vdc 170 Vde 170 Vde Supply Voltage (Minimum) See (Note 2) 170 Vdc 170 Vde 170 Vde 250 Vde 170 Vde 170 Vde Cathode Current (Peak ) See (Note 1) 4.0 ma 3.5 ma 3.5 mu 5.0 ma 4.5 ma 45 mu Test Conditions (See Basic Circuit, Fig. 1) Supply Voltage 170 Vde 170 Vde 170 Vde 250 Vdc 170 Vde 170 Vde Series Resistor ISK 1OK 1OK 43K 68K 6.8 K Cathode Current: (Minimum) 1.5 ma 1.5 ma 1.5 ma 2.0 ma 1.5oma 1.S ma (Maximum) 3.0 ma 3.0 ma 3.0 ma 3.0 ma 4.0 ma 4.0 ma Recommended Operating Conditions (DC) (See Basic Circuit, Fig. 1) Supply Voltage (E) 170V]250V]300V} 170V 2s0V Boov [1 70V PS0V BoOV [170V/250V]300V [170V Ps0v fRoov | 170V Bsoy [300V Series Resistor (R) 15K} 56K] 82K] 10K] S6K| 82K | 10K { S6K] 82K § 12K] 43K] 62K] 68K 139K] 56K] 6.8K |39K] 56K Note 1. Due to life considerations only long life NIXIE tubes are tube type. However, the use of the highest voltage available, with recommended for pulsed operation. the appropriate series resistor to maintain cathode current within the Note 2. The minimum supply voltage should be as stated for each specified limits, is recommended. MECHANICAL DATA STANDARD SUPER BS092 . B609] 6844A 8037 (B3031) Long Life 7153 BOO33 Long Life Regular Long Life Wide Angle Regular Long Life Wide Angle Outline Drawing Figure 5 Figure & Figure 6 Figure 7 Figure 7 Figure 7 Sockets Page 23 Page 23 Page 23 Page 23 Page 23 Page 23 Wiring Plugs Page 23 Page 23 Page 23 Page 23 Page 23 Page 23 Pin Straighteners Page 23 Page 23 Page 23 Page 23 Page 23 Page 23 Pin Connections Figure 8 Figure 8 Figure 8 Figure 8 Higure 8 Pigure § 1.080 MAX. —p—- 6I0 | 1-088 MIN. q | NOM. ; 1.212 MAX, le 1350 DIA. 1.000 MIN. 1.080 DIA. [ >| MAX. 1.125 MAX. MAX, 1350 fT . —t f 4% MAX. 4 E oa +— —— MAX. 4 toga max, Rohe. Lf 656 DIA. B.C. .250 1-686 OIA. B.C. NOM. Fig. 7 — Outline Drawing for all Super Tube Types Fig. 5 — Outline Drawing for 6844A and B5031 Standard Type Tubes PIN CONNECTIONS PIN NO CHARACTER -610 1 — Internal Connection NOM. a § 2— Anode 1000 MIN. 1.080 3— Numeral 0 1125 MAX. . 4— Numeral 9 it aa { 4 DIA. MAX. 5 — Numeral 8 1,080 nN ny + 6 — Numeral 7 DIA. MAX. 064 MAX. BOTTOM VIEW i Numeral 6 i .250 — nternal Connection NOM. 656 DIA. B.C. — Numeral 5 For Proper viewing — 10 — Numeral 4 Pins 1 and 8 should be 1] — Numeral 3 Fig. 6 —- Outline Drawing for B5092 Type Tube petically aigned with 12 — Numeral 2 13 — Numeral 1 Fig. 8 — Pin Connections ENVIRONMENTAL DATA Contact Applications Department for specific data on individual tube types — See Page 20 for general information 7 LARGE AND JUMBO TUBES ELECTRICAL DATA LARGE JUMBO B8&09T B7094 Long Life Long Life Wide Angle Wide Angle Absolute Ratings Tonization Voltage (Maximum) 170 Vde 300 Vde Supply Voltage (Minimum) See (Note 2) 170 Vdc 300 Vde Cathode Current (Peak) See (Note 1) 6.5 ma 7.5 ma Test Conditions (See Basic Circuit, Fig. 1) Supply Voltage 170 Vdc 300 Vde Series Resistor 5.6K 27K Cathode Current: (Minimum) 3.0 ma 4.0 ma (Maximum) 6.0 ma 7.0 ma Recommended Operating Conditions (DC) (See Basic Circuit, Fig. 1) Supply Voltage (E) 170V] 250V] 300V 300V Series Resistor (R) §6K] 227K] 33K 27K Note 1. Due to life considerations only long life NIXIE tubes are recommended for pulsed operation. Note 2. The minimum supply voltage should be as stated for each tube type. However, the use of the highest voltage available, with the appropriate series resistor to maintain cathode current within the specified limits, is recommended. MECHANICAL DATA LARGE B809! Long Life Wide Angle JUMBO B7094 Long Life Wide Angle Outline Drawing Figure 9 Figure 10 Sockets Page 25 Page 25 Wiring Plugs Not Applicable Not Applicable Pin Straighteners Page 25 Page 25 Pin Connections Figure 11 Figure 11 PIN CONNECTIONS - PIN NO CHARACTER 2. I I. t Jt ]— Interna) Connection 2— Anode abo nen vou] 1.375 01a. =! 3— Numeral 0 4— Numeral 9 ; Fig. 9 — Outline Drawing for all Large Tube Types 5 — Internal Connection 6 — Internal Connection 3.100 DIA, —e- 7— Numeral 8 MAX. 8 — Numeral 7 9— Numeral 6 10 — Internal Connection 2580 2.450 BOTTOM VIEW tl — Internal Connection 2.650 12 — Numeral 5 2.000 For Proper viewing — 13 — Numeral 4 { NOM. Pins 1 and 10 should 14— Numeral 3 . ww be vertically aligned 1S — Internal Connection TO with Pin 10 on top 16 — Numeral 2? .300 J +275 17 — Numeral | MAX. L375 DIA.e— = MAX. Fig. 10 — Outline Drawing for Jumbo Tube Types Fig. 1 — Pin Connections ENVIRONMENTAL DATA - Contact Applications Department for specific data on individual tube types — See Page 20 for general information TECHNICAL MEMORANDUM NIXIE TUBE CHARACTERISTICS AND CIRCUIT DESIGN DATA SUMMARY The electrical characteristics are explained and circuit design data is discussed. Ionization and operating voltages as well as full glow current requirements are defined. The method of selecting the circuit parameters such as supply voltage, series resistance, pre-bias voltage and switching voltage are discussed. ELECTRICAL CHARACTERISTICS The equivalent circuit of a NIXIE indicator tube is shown in Figure 12. Ry ANOOE VV —$—<— 4 4 . G E> Ey 2 CATHOOE Fig. 12 — Nixie Tube and its Equivalent Circuit This circuit represents the NIXIE tube electrically when con- sidering the anode and one of the tube’s ten cathodes. When looking into terminals A and B, this “two terminal” device will appear as a constant voltage source, E;, in series with an internal impedance, Ry (approximately 10 K ohm) and a diode. The diode represents the fact that the NIXIE is a cold cathode gas tube in which current flow ceases when E. drops below the value of E:. E; is equal to E,-IRp where E, is the average sustaining voltage under average current conditions. If E, were absolutely constant for each NIXIE tube, then all tubes would exhibit the same tube voltage drop and cathode current. However, variations exist in E; between different tube types and to a lesser extent from tube to tube within a given type. Therefore, corresponding variations will exist in the tube voltage drop and cathode current of individual NIXIE tubes. These variations are shown for the type B5092 Stan- dard NIXIE tube by the parallel lines which represent the limiting curves of the tube characteristics in Figure 13. NIXIE indicator tubes are current operated devices. They re- quire a minimum cathode current density to assure complete glow and a maximum cathode current limit to provide maximum life. Sufficient B-+ voltage and appropriate series resistance are the means for assuring ionization and control of the cathodes within the specified limits. Figure |, page 6, 1s the basic NEXIE tube test circuit. This cir- cuit was used to obtain the characteristic curves of the type B5092 Standard NIXIE tube shown in Figure 13. The same circuit with fixed B+ and fixed series resistor is used as a production test for all types. The B+ and fixed resistor values as well as the cathode current limits for the various NIXIE tubes are shown in tabulated form under Test Conditions in the Electrical Data Section of the brochure. Figure 13 shows the limits of the tube voltage versus cathode current (E, vs, I.) characteristics curves for the B5092 NIXIE tube. The following interpretation apd discussion of the character- istic curves applies equally to similar curves which could be drawn for all types of NIXIE tubes. As shown in Figure 13, a 170 volt, 10 K ohm load line intersects the characteristic curves at points E and F corresponding to the cathode current limits of 1.5 ma and o 5 THE TUBE CHARACTERISTICS 2 FALL WITHIN AND ARE APPROX. > PARALLEL TO THESE LIMITING ~ 200-4 CURVES. u w < 5 i f id ---7 ! + > -—— ; | ! w ' ! ' 3 1004 ' { r L | Lower ! } _ UPPER | TEST LimiT H ; TEST LIMIT + + + T 9 ike} 2.0 3.0 CATHODE CURRENT Ix (mA) Fig. 13 — Electrical Characteristics-Type B5092 Nixie Tube 3.0 ma. Other recommended load lines are also shown. The mini- mum cathode current necessary for full glow of any cathode is slightly less than 1.5 ma for the type B5092. Increasing the cathode current results in greater intensity, but shortens tube life. In order to obtain sufficient brilliancy and maximum tube life, the cathode current should not be allowed to exceed the limits of 1.5 ma to 3.0 ma. The optimum design would be a constant current circuit providing a cathode current of 2.25 ma for this tube type. SUPPLY, IONIZATION AND SUSTAINING VOLTAGES As mentioned above, the NIXIE tube is basically a current operated device. However, the voltage necessary to provide the required cathode current is also very important for satisfactory operation of the tube. As shown in the Electrical Data Section of this brochure, the recommended minimum supply voltage is the same as the maximum ionization voltage. This is to assure ioniza- tion and proper operation of the particular NIXIE tube type. For example, the maximum ionization voltage and minimum supply voltage for the type B5092 is 170 volts. Although many B5092 NIXIE tubes will ionize below point B (Figure 13), the ionization voltage range should be considered to extend up to point A. (170 volts). Therefore, A, represents the recommended minimum supply voltage. In addition. if a B+ voltage less than the minimum recom- mended supply voltage of 170 volts is used, a load resistor smaller than 10 K ohms would be necessary to establish the average cathode current of 2.25 ma for the type B5092. The resulting loadline would intersect the limiting characteristic curves above and below the recommended cathode current limits. Again, this infers that the use of a supply voltage of less than +170V for the type B5092 is not good engineering practice and isnot recommended. In Figure 13, points E and F projected onto the ordinate estab- lish points B and D. The distances OB and OD, therefore, represent the limits of tube voltage drop as the operating point moves along the 10 K ohm loadline from point E to point F. The voltage represented by distance OC is the average tube voltage drop under average current conditions or E. SERIES RESISTOR For most B5092 applications, the results obtained by using a 170 volt supply in conjunction with a 10 K ohm foad resistor are satisfactory. However, in many applications. it is preferred to keep the range of cathode currents and glow intensitics to a minimum. One way of accomplishing this is to select a higher sup- ply voltage and use an appropriate higher value of load resistance. The higher the B~ and series resistor, the more nearly a constant current is approached and, as a result, better NIXIE tube operation is obtained. Knowing the available supply voltage, the method of selecting the series load resistance is as follows, using Figure 13: (1) Select the center value of cathode current, e.g. 2.25 ma for the type B5092. (2) Erect a line normal to the abscissa at this point. This normal line will intersect a line drawn midway between and parallel to the limiting characteristic curves at point G. (3) Connect this point G with the selected supply voltage on the ordinate, ¢.g. 250 volts point Az. The inverse slope of this line will represent the necessary load impedance which in this case is 47 K ohms. In other words, the voltage drop across the series resistor must be such that the tube voltage drop (E,) is the same for al! values of supply voltage. For the type B5092, the series resistor (Ri) in K ohms for any given supply voltage is B+ minus 147 volts (E.) divided by 2.25 ma (average cathode current). It is evident that the range of cathode current diminishes as the slope of the loadline becomes steeper. Therefore, a higher supply voltage is always preferred, e.g. points A, or A;, as compared to Ai. In order to simplify the selection of series resistors for the vari- ous NIXIE tube types, the following chart has been prepared. By merely substituting the selected operating voltage (B+), the average tube voltage drop, E,, and the average cathode current, |, (av), in the formula B+ — E, L= Ik (av) the approximate value of the required series resistor (R.) can be obtained. Tube Group Tube Type E, I, (av) ma. Miniature 7009 102 95 7977 (B4032) 154 1.05 B4021 102 1.05 B408] 102 1.05 Standard B5092 147 2.25 8037 (B5031) 147 2.25 6844A 135 2.25 Super B6091 147 3.0 B6033 147 3.0 7153 43 2.5 Large B8091 45 4.75 umbo "B7094 350 5.5 PRE-BIAS From the preceding discussions, it might be assumed that a signal equal in amplitude to the minimum supply voltage is re- quired to turn “on™ (ionize) the selected NIXIE tube number or character (cathode); however, this is not true since in practice, the switching device driving the NIXIE tube need only be capable of switching a much smaller pre-bias voltage. This is particularly important when the tubes are to be used in low voltage semi- conductor circuits where large amplitude signals are not available. Pre-bias voltage is defined here as the potential difference be- tween the | “on” cathode and the 9 “off” cathodes within the tubes. The curves in Figure 14 show the range of currents which an “off” cathode will draw as its potential is changed with respect to the “on” cathode. The curves were obtained by the use of a i . Esupecy Fig. 15 — Basic Nixie Tube Pre-Bias Circuit circuit such as that shown in Figure 15. In this circuit. one cathode is grounded and, therefore, ionized while another cathode ts con- nected to the pre-bias supply (E..). The curves in Figure 14 show that if the “off” cathode voltage is raised above the sustaining voltage (E,). it will take over as the anode and accept electron current. The anode and series anode resistor would then lose control of limiting the “on” cathode’s current. Figure 14 also shows that as the “off” cathodes’ voltage is lowered below the anode voltage, it will begin to accept ion current. If this ion current is excessive, the “off” cathode will become ionized and produce a background haze. From this discussion it can be seen that the upper limit of the pre-bias voltage is less than the lawest sustaining voltage of a “high current” NIXIE tube (point D, Figure 13) for type BS092. The lower limit of the pre-bias voltage is determined by the objec- tion of the eye to the background haze caused by the ionization of the “off” cathodes. Since NIXIE tube cathodes are stacked within the tube envelope, the distance between combinations of “on” and “off” cathodes will be different and consequently the effects of pre-bias will vary from one combination to the next. This is why a spread of curves representing minimum and maximum effects is shown in Figure 14. The area within the dotted line represents that area in which objectionable background haze occurred for the various combina- tions. The table below illustrates pre-bias voltage limits for the various NIXIE tubes. AREA OF iS \ EXCESSIVE = w & > id = GLow S & woe WKY c=] E CON 2 0 T T T T T T T T T 3 w 30 45 60 7S 90 108 120 135 150 w '00 > Fa PRE-BIAS VOLTAGE Epb (VOLTS) x < a oe 200 42 B 5092 | R= 10 K E SUPPLY VARIED TO MAINTAIN I, 22.25mA Fig. 14 — Pre-Bias Voltage vs Current Characteristics of the Type B5092 Nixie Tube Pre-bias Voltage Limits Tube Group | Tube Type (referenced to the “on” cathode) Miniature 7009 50 Vito 75 V B4081 50 Vto75V B4021 S50 Vto75V 7977 (B4032) 50 V to 120 V Standard All Types 50 V to 120 V Super A pes 50 V to 120 V Large All Types 50 V to 120 V Jumbo All Types 50 Vto 120 V Note 1: Due to the small physical size of the Miniature NIXTE tubes, a relatively greater degree of background haze is evident for a given pre-bias voltage; however, the Low Voltage Miniature NIXIE tube type B4021 is a specially selected tube. This tube exhibits less background haze than other Miniature types at the lower limit of pre-bias voltage (50 V). Note 2: In general the same pre-bias limits apply to both numeral and special character tubes in a given tube type. The lower the pre-bias voltage, the lower the voltage swing required from the driving source. Due to the present availability of a number of different types of economical medium and high voltage transistors, the design engineer has latitude in the choice of a particular device with which to drive the NIXIE tube. De- tailed information concerning transistor operation of NIXIE tubes will be found in the Applications Section of this brochure (Pg.14 ). The information includes a listing of currently available transistors which are suitable for use with the tubes, as well as photographs of completely packaged transistor drive modules (TRIXIE® mod- ules). Specifications on the packaged modules will be found in the Accessories Section on Pages 22 and 24. APPLICATIONS INFORMATION SUMMARY Typical applications of NIXIE tubes are discussed. Specific methods of operating NIXIE tubes are described. including electro- mechanical switches, transistors and BEAM-X® switches. Typical power supply circuits and specialized circuit techniques such as dimming and blanking are discussed. Suggested methods of mount- ing and environmental data are given. NIXIE TUBE APPLICATIONS NIXIE tubes have found application in literally every type of equipment from elevators to electronic instruments, from process control flowmeters to missile count-down displays. The following is a brief listing of some typical applications which indicate the scope, versatility and capabilities of these unique readout devices. Digital Clocks Aircraft Channel Indicators Computer Console Readouts Airline Displays Stock Quotation Displays Frequency Counters Digital Voltmeters Direct Readout Oscilloscopes e Flowmeters @ Tank Level Indicators In each of these applications. a particular set of conditions exists which dictates the manner in which the tubes will be operated. In some cases, Occurrences are to be counted and displayed using either electronic or electro-mechanical circuits: in others, coded information must be converted to decimal form and displayed visu- ally. In still other applications, a simple ten-position switch can select the desired characters without need for elaborate circuitry. On the following pages, various methods of NIXIE tube operation are described in detail to assist the design engineer in incorporating the tubes into his equipment. DRIVER CIRCUITS BEAM-X SWITCH CIRCUITS Since the NIXIE indicator tube is a current operated device, the ideal driver for the tube is a constant current source such as the BEAM-X Switch. Thus, the NIXIE tube and the BEAM-X Switch are inherently compatible devices. Having been designed as com- panion units, their operating voltages and currents are such that optimum performance of the NIXIE tube readout is assured. Digital Tachometers Flight Simulators Teaching Machines The BEAM-X Switch is a high-speed, ten-position, electronic switching device. Within the device are ten arrays of independent elements positioned around a centrally located cathode. See cross section Figure 16, SPADE - Beam forming & locking element TARGET ~ Output {electrode ond magnet \ swircuine GRID (esd) SHIELO GRID Serial oviput slement SWITCHING GAID {even} Fig. 16 — Beam-X Switch and Cross Section An electron beam can be formed from the cathode to any one position and then can be switched sequentially or at random by use of the elements in each array to any of the other nine positions of the tube. When the beam is formed at a given position, the out- put current available at that position can be used to operate NIXIE tubes, printers, and to perform gating or presetting functions. The versatile design of the BEAM-X Switch allows it to perform the two most common functions in a readout system. The BEAM-X Switch can count pulses reliably at both low and high frequencies. and itcan decode binary coded decimal information to decimal form. DECADE COUNTING WITH THE BEAM-X SWITCH. A number of different techniques can be utilized to operate the BEAM-X Switch as a counting device. Typical are 100 KC and 1 MC flip-flop circuits which use transistors, vacuum tubes or Nuvistors to drive the switching grids of the BEAM-X Switch and advance the electron beam through the ten positions of the device. A cascade output pulse from the ninth or tenth position of the BEAM-X Switch is normally used to drive succeeding decades. At lower frequencies (below 10 KC), flip-flop drive circuits can be eliminated and the switching grids can be pulsed directly. In either case, the ten constant current outputs of the BEAM-X Switch operate remote or local NIXIE tube readouts directly without need for decoder, buffer or amplifier circuits. BEAM-X Switch/NIXIE tube circuit design criteria is discussed in detail in the BEAM-X Switch brochure (BX-535-A). In the following sec- tions, typical BEAM-X Switch circuits are shown. TRANSISTOR BLAM-X COUNTER CIRCUITS Figure 17 shows the schematic diagram of a | MC _ Transis- torized BEAM-X Counter. A total of only eleven active com- ponents (three silicon transistors, seven diodes and one BEAM-X Switch) are required to perform the counting function. In addition to operating the NIXIE tube directly, ten electrical outputs are available to drive gates and printers. +250V. |__ 98092_nixie® TUBE TARGET OUTPUTS-»o-4 oO o-+F 0-4 0-4 04 0-4 OF 0-4 0-4 On me alet) TP ST dT Sy ay gy pez { g 2F| 5] Fl Fl Fl Fl FS] Fae a3 (B2ppt aks Edy | 1) 7) yt | i ed QDS SUT TT Th ay 8 |e 6o_ 4) al Bal Oy Gal Ga SAT Gay fay | OY Oy OGY SY Sy SL SY Sg PO. ryt YE Yt Yad Ye YY BX 2000 Lug IN722 J asx CLEAR wy RESET 6.2K 5 6.2K gz N 2 3 39ppF CARRY ING43A % gg [ 43K q| 66k i: 24K | OUTPUT INGASA 220? Po tee’ )s-szer Xs-3zei (Spot 220p pe jon; 310K COUNT ; at eh WOKS Ons FOI! —-FIOK ALTERNATE = BINARY BINARY RESET RESET Figure 17 — DC-116 Schematic 12 This circuit is commercially available as a plug-in module which is designed for front panel mounting in direct readout counting systems (see Figure 18). For counting applications requiring 110 KC maximum pulse resolution, a germanium transistor circuit is available. This circuit is electrically compatible with the 1 MC circuit shown above so that complete high-speed systems can be designed using the two units together. Fig. 18 — DC-116 Module Each unit contains an integral NIXIE tube (standard long life Type B5092) and a magnetically shielded BEAM-X Switch to facilitate side-by-side mounting. In addition, a 110 KC unit is available without integral NIXIE tube for those applications in which remote readout is desired. Complete specifications for the units can be found in the BEAM-X Modules Brochure #405. VACUUM TUBE BEAM-X COUNTER CIRCUITS BEAM-X Switches can be driven at all frequencies with suitable vacuum tube flip-flop circuits. A typical 110 KC circuit is shown in Figure 19. Here a transistor amplifier is used to couple suc- ceeding stages. +250V. | ss092_nixie® Tuse & Top oy ys Te ye ne) E5I0K SI00K Q 9 T1496 |CASCADE (OUTPUT +60¥. s eVfut lel etyel (<td yet ett] al 3 BF | BF [BF 1BF/ BS BF | BF Be BF S| ar | FAK TA lol loll Lat led . Some] PTL ETT PTL PTL Py Py : { TTT ty yy 4 G | Sy OY Sel Ga Sy Sa OY Og C8 LMM MMMM Ye +60V eNO "2" "3" "ays" "e"_"7"_ "a" "9 I BX 2000 RESET S9pnf 33 +100V. 24K | 1SOK 150K | 24k ah ft 7 5965 ra 47K oH INPUT 68, 1N627 |'N627 FLIP 62ks SSIK 382K tour FLOP 1t RESET Sly Suk +iBV 4 Fig. 19 — 110 KC Vacuum Tube Counter Circuit A unique vacuum tube-BEAM-X Switch combination is that of the Burroughs BEAM-X module, Type DC-112. This unit utilizes a high gain screen grid pentode to provide the cascade output to drive the next succeeding decade. This unit is insensitive to large noise pulses. For this reason, the counter is ideal for use in industrial counting systems where electrical noise can cause diffi- culties with flip-flop circuits which are relatively noise sensitive. The circuit for the DC-112 module is shown in Figure 20 below. TO REMOTE READOUT ft n ~ = . lL, +39 |+39/=39 |739|—39 lo +3 i Tl CARRY x Ich} 66K |OUTPUT *60¥. Gt) Be [5s [9s (os) Ss | ios | se | 3 | Ss cot RESET SPLINT INT [IS] ley | ind | fo ry | fev) | ov) 00Yd —k4> Ui big | Lig | te L_4 INPUT 39,42 6 SHIELD é Oe OR 08 58 [Oe Ba By 64 Oe Ss GRID lOUTPUT fw VY VM YY | BX 1000 RESET C x INPUT L 6 39h 3.3 $6703 MH +200V. sores 3 Fig. 20 — Beam-X Switch Counter Circuit. A remote NIXIE tube can be operated from the target output terminals directly. Figure 21 is a photograph of the unit. Fig. 21 — DC-112 Module NUVISTOR BEAM-X COUNTER CIRCUITS Figure 22 is supplied to show the compatibility of the BEAM-X Switch with Nuvistor tubes for decade counting. Here, a two Nuvistor tetrode flip-flop and a Nuvistor triode output amplifier are used. This circuit is capable of 1 MC operation. This circuit shows the ability of a high current BEAM-X Switch to operate multiple remote NIXIE tubes of miniature, standard or 33K 85092 NIXIE” TUBE CC (Pere rerrrr 33K +150v. 65092 Nixi€@TUBE v 2 i, a - SO - - - HUUURHRU wn 620K ANA, 0 So POOF EOLA AED Xe i 27K 2 BINARY 3 INPUT ='4 COUNT T Slap INPUT Fig. 22 — I MC Nuvistor-Beam-X Switch Counter Circuit super sizes. In Figure 22, 2 type B5092 standard tubes are being operated remotely. The BEAM-X Switch, Type BX-2001 used, provides a minimum of 4.0 ma of constant current output which is sufficient to light 4 miniature NIXIE tubes or 2 standard size tubes. Transistor and standard vacuum tube circuits can also be combined with high-current BEAM-X Switches to perform the same function. DECODING WITH THE BEAM-X SWITCH One of the most common circuit requirements in readout systems is the need for conversions of binary coded data to decimal form. In almost every case, the information is available for only a short period of time so that a decoding device which has both data storage and high speed operation capabilities is required. A typical example is the activation of computer console displays from binary coded decimal information. The BEAM-X Switch is a device which satisfies all of the basic requirements of a decoding system. It has high access speed (ten microseconds or less) and provides electronic storage in decimal form for the data. It can be combined with transistors in a circuit such as that shown in Figure 23. This circuit is designed to decode 8-4-2-1 BCD to decimal form with four-line access and single line read gate control. In performing the decoding function, the ten-position BEAM-X Switch operates as a homing switch. A read gate pulse, amplified by a transistor, clears the previously stored information from the BEAM-X Switch and then resets the switch to the “zero” position. As the BEAM-X Switch resets, a second transistor generates an information access gate pulse which turns on four binary infor- mation input transistors. Depending upon the binary information at the input to these transistors during the access gate time, voltage levels are established within the BEAM-X Switch so that the beam switches to the decimal output position corresponding to the binary input. Upon termination of the information access gate, the four binary input transistors are turned off. The BEAM-X Switch retains the information stored in it until the next conversion cycle begins. This type of decoder operation is commercially available in a series of BEAM-X decoder modules (Types DC-115-A, DC-115-B, DC-115-C, etc). The modules are designed to decode various BCD codes to decimal form. + [85092 nixie® TUBE _ ee +200 V. x oO op a Ge? Ge “ge “2° 9g ge —oO 8s \¢__9 3 3 3 8 gg ) 4 N xt x xt x | x x x x ms o3| os os os 19s [9s xs m3 as ed os ne as 83 Os rp: tt x xl 4 Ce) 3 s $ 3 pf 9s os Ss 33 N - m ao Go Da Oe] Oe 4] Oe] Se] SQ] Sal OI] Oe VVVVVVU VY GENO 2 ase 7" ve" a BX 1000 100p.F TL 2NI310 75K [ +4 , 18K z tL2M q +1Z2VO—s owe 3 e9 x x 3x 6.8K Si tonsirs > = READ BK | = | SNI3INS PULSE Sipph 47K YY -12¥. SG 701'5 O=-6 TO~I2 | = GROUND Fig. 23 — Transistorized Beam-X Switch Decoder Fig. 24 — DC-115 Module A photograph of a typical DC-115 module is shown in Figure 24. Each unit is designed to operate remotely located NIXIE tubes directly. The table below lists the various modules and the data which they convert. Detailed technical specifications can be obtained by referring to the BEAM-X Modules Brochure #405. Other codes can also be converted and modules can be prepared to your specifications. Decoder Code Type # Converted DC-115-A 8-4-2-1 DC-115-B 8-4-2-1 (constant current read gate) DC-115-C 4-2-2-1 DC-115-D 2-4-2-1 DC-115-F $-3-1-1 In the preceding sections, typical circuits have been supplied as a guide to the operation of NIXIE tubes in electronic counting and decoding systems by means of the BEAM-X Switch. The BEAM-X Switch holds a definite advantage over other electronic techniques in these areas since the device replaces as many as eighteen transistors, and forty diodes or resistors which would be required to perform the same function in an all-solid state design. This can be seen by comparing the all-transistor decoding