ECA 191-D-1985 Measurement of Direct Interelectrode Capacitances of Electron Tubes《电子管的直接电极间电容的测量》.pdf

1、EIA 171-D 85 m 3234600 0028647 7 m ANSI/EIA-191-D-1984 APPROVED NOVEMBER 28, 1984 MEASUREMENT OF DIRECT INTERELECTRODE CAPACITANCES OF ELECTRON TUBES EI A- l 9 l -D (Revision of RS-191-C) JANUARY, 19 8 5 Engineering Department. I ELECTRONIC INDUSTRIES ASSOCIATION EIA 171-D 85 323qbOO 0028650 3 NOTIC

2、E EIA Engineering Standards and Publications are designed to serve the public interest through eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay th

3、e proper product for his particular need. Existence of such Standards and Pub- iications shall not in any respect preclude any member or non-member of EIA from manufacturing or -selling products not conforming to such Standards and Publications, nor shall the existence of such Standards and Publicat

4、ions preclude standard is to be used either domestically or internationally. Recommended Standards and Publications are adopted by IA without regard to whether or not their adoption may involve patents on articles, materials, or processes. By such action, EIA does not assume any liability to any pat

5、ent owner, nor does it assume any obligation whatever to parties adopting the Recom- mended Standard or Publication. This Standard contains the major technical contents of International Elec- trotechnical Commission miblication No. 100, Methods for the Measurement ofDirect Interelectrode Capacitance

6、s of Electronic Tubes and Valves (1962). It differs from Publication No. 100 in certain important respects: a) EIA- 191-D contains, as an addition, definitions of bridge operating frequency ranges for the RF and transmission methods and a new range definition for an audio frequency method; b) it con

7、tains a method of measuring capacitance using standard commercial equipment sockets; and c it contains a technical statement added in para. 1.4 to define when to use the audio frequency method in lieu of the RF or transmission methods, particularly when measuring low capacitances in an electron tube

8、 wherein exceptionally high shunting tube capacitances simultaneously exist in the same tube. These differences have been called.to the attention of the U.S.N.C. Technical Advisory Group (TAG) for IEC Technical Committee 39 (Electronic Tubes), and resolution of these differences will be sought in fu

9、ture meetings of TC39, their voluntary use by those other than EIA members, whether the A . Published by . Electronic Industries Association Engineering Department 2001 Eye Street, N.W. Washington, D.C. 20006 Copyright 1985 ,Electronic Industries Association PRICE: $9.00 Q NOTE: The prefix “RS“ is b

10、eing deleted in favor of “EIA.“ eventually be reflected in all EIA Standards. editorial change to provide more positive identification of the source for the standard - there is no technical significance to the change. This change will This is simply an EIA 193-D 5 3234600 0028653 5 = EIA- 191-D MEAS

11、UREMENT OF DIRECT -ODE CAPACITANCES OF ELWON TBES INDEX Item 1. Methods of Teats . . . . . . . . . . . . 1.1 Definitions . . , . . . . . . . . . 1.2 Measurement of Interelectrode Capacitances of Tubes Tables of Connections of Electrodes of Tube Sections Table I - Receiving Tuba . . . . . . , Table I

12、I-CathodeRayTubes . . . - - Table III - Gas Tubes . . . . . . . . . Table IV - Phototubes and Multipher Phabtubes , Table V-HighPowerVacuumTubes . , . . 1.3 Conditions of Tests . . . . . . . . . . 1.4 CapacitanceMeasuring Circuits . . . . , . 2. Standard Capacitance Sockets . . . . . . . , Page . .

13、1 . . . . . . . . . .1 , . . . . . . . . 1 1 . . . . . . . . . .4 . . . . . . . . , .5 . ;5 5 . . . . . . . . . .6 ,. 7 . , . . . . . . . .9 3, Standard Shields . . . . . . . . . . . . . . . . . . . . . . 10 4. Standard Cap Connectors . . . . . . . , , . . . . . . . . . . 15 5. SpecialTypes . . . .

14、, . . . . , . . . . . . . . . 15 i capacitance to other objects shall be kept at a minimum. On all types, for elements terminated in two or more pins or leads, all such pins or leads shall be connected together. In those cases where two or more elements are internally connected,. the combination sha

15、ll be treated as the major element of the combination. For example, a suppressor grid internally connected to the cathode shall be considered the cathode in the tables of connections, For directly heated filament types, the filament is the cathode electrode. The application of these principles to th

16、e capacitance normally measured in various types of tubes are indicated in Tables I to V inclusive. applications. TABLES OF CONNECTIONS OF ELECXRODES OF TUBE SEClTONS FOR MEASURING DIRECT INTERELECTRODE CAPACITANCES TABLE 1-RECEIVING TUBES. Capacitance Measure Between Ground Indirectly Heated Heater

17、-Cathode Heater and cathode All other elements, Cathode Types Diode Plate-All Illate and (cathode Other units shields, metal parts, etc. -f- heater + shields + metal parts, etc. ) e EIA LSL-D 85 m 3234600 0028b53 7 EIA-I91 -D Page 2 . Tupe of Tube Capacitance Measure Between Ground Diode (contd) Cat

18、hode-Diode Plate Cathode and (diode Other units date 4- heater 4- hields + metal parts, etc.) Coupling (Between Diode plate and plate All other elements, Units) of other unit (8) shields, metal parta, etc. Coupling (Between Diode plate and (contct) Input (2) Signalgrid (2) and (all other elementa, s

19、hields, metal parta, etc.) output Plate and (all other elementa, shields, metal parts, etc.) Coupling Signal grid (I) and Ail other elements, signalgrid (2) shields, metal Signal Grid-Mixer Signal grid and All other elements, Plate mixer plate shields, metal parts, etc. R.F. Input Signal grid and (a

20、ll other elements, shields, metal parts, etc.) Mixer plate and (all other elements, shields, metal parts, etc.) parts, etc. Mixer Output Converter Osc. Grid-Osc. Plate Osc. Input Osc. grid and (cathode Osc. plate Osc. grid and osc. plate All other elements, shields, metal parts, etc. + heater -t- mi

21、xerplate + signal grid + shields + metal parts, etc.) + heater + mixer plate + signal grid + shields + metalparts, etc.) osc. output Osc. plate and (cathode Osc. grid O Osc. Input* Oso. grid and (all other elements, shields, metal parts, etc.) osc. output* Cathode and (heater + Ose. grid mixer plate

22、 + signal grid + osc. plate + shields + metalparts etc,) Osc. Grid-Cathode* Osc. grid and cathode All other elements, shields, metal parts, etc. Osc. Grid-Mixer Plate* Osc. grid and mixer All other elements, plate shields, metal parts, etc. Osc. Grid-All Except Osc. grid and (mixer Cathode Cathode p

23、late + signalgrid + osc. plate + heater + shields + metal parts, etc,) Coupling Osc. double- sided deflection , parts, tc.) ._-. -.- Grid 1 - All Grid 1 and (all other elements, shields, metal . parts, etc.) D1 -c D2 D1 and D2 All other elements, D3-D4 D3 and D4 All other elements, fsld hll D1 and (

24、all other elements, shieds, shields, metal parts, etc., except D1 and D2 rrhields, metal parts, etc, except D3 and D4 - D3 and (all other elements, shields, dements, shields, metal Pam, etc. ) Electros single+ metal parts, eh.) sided deflection _-_-._F_ .,- 0% - Alt DI and (ail other dements, shield

25、s, metal parts, etc.) , . _- - nk-Alt Da and (all other elements, shields, metal parts, etc.) -_I -.: - i-wLc. I* 1) For ctbodc mg tubee tb int+iiffeE aI all other dements except anode at ground, EIA 191-D 85 m 3234600 0028656 4 m EIA-191-D “- Page 5 TABLE III-GAS TUBES e Tvpeof Tubs Capacitance Mea

26、sure Between Ground All Grid-Anode Grid and anode All other elements, shields, metal parts, etc. Grid-Cathode Grid and (cathode + Anode heater + shield grid + shields + metal parta, etc.) Anode-Cathode Anode and (cathode + Control grid heater + shield grid + shields + metal parts, etc.) grid shields

27、, metal All other elements, parts, etc. Shield Grid-Anode Anode and shield _I Shield Grid-Cathode Shield grid and Anode (cathode + heater + shields + metal parts, etc.) TABLE IV-PHOTCYIUBES AND MULTIPLER PHOTOTUBES Typeof Tube Cupacitance Measure Between Grond Gas and Vacuum Anode-Cathode Anode and

28、(cathode + Types Eihields + metal parts, etc.) e Gas and Vacuum Anode-Cathode Anode and (cathode + Anode and cathode of Twin Types (Each Unit) shields + metal unit not under test. Darts. etc.) Coupling (Between Cathode of one unit All other elements, Units) and cathode of other shields, metal parts,

29、 etc. Coupling (Between Anode of one unit All other elements, Units) and anode of other shields, metal parts, etc. Multiplier Types Anode-All Anode and (all other elements, shields, metal parts, etc.) Anode-Last Dynode Anode and last dynode All other elements, shields, metal parts, etc. TABLF: V-RIG

30、E POWER VACUUM TUBES* Type of Tube Capacitance Measure Between Ground Indirectly Heated Heater-Cathode Heater and cathode All other elements, Cathode Types shields, metal parts, etc. a .- . . EIA 191-D 5 m 3234600 0028657 6 m E$I-ISlcD Page 6 i I* 3 1. - . HIGH POWER VACUUM TUBES* -nusd) TyyiBaf ZlO

31、rlje . Capacztanae Maaszcre Bets, etc.) Output Plate and (grid + (Grounded Grid) racreen l- upareesor -F shields + metalparb, -. etc). Twin Triode, Tetrode, Doupling between Grid of one unit All other and plate of other elements; shields, . Pentode units (grid to plate) metal parts, etc, Plate of on

32、e unit All other Coupling between and plate of other . elements,.shieldB, - plate) I. . metal parts, eta. units (plate to units (General) one section and = . - elements, shields, electrode of other - metal parts, etc. .-. . : -Output Plate and (cathode + Grid : ; . . heater + screen i- .- Cathode, h

33、eater .* , Coupling between -Electrode of . All other *For hleh Dowet vftcuum tme6 employing metal sleeve-type Mes with the aleeve not connected Internalb to iint We Din or electrode, the aleere shall float for all measurcments und shall not be connected to any meamrement oltcoit an are other metal

34、art ta. _ 1.3 Conditions of Tests 1.3.1. For all tubes, interelectrode capacitances shall be measured with the cathode cold and with no direct 1.3.2 For all tubes, interelectrode capacitances shall be measured using one of the three following methods: 1) with standard capacitance sockets, 2) with co

35、mmercial equipment sockets, or 3) with leads connected directly to the tube terminals. 1.3.2.1 Standard Capacitance Sockets Interelectrode capacitance may be measured,using the standard capacitance sockets and the standard capacitance connectors described in Section 2, 4, and 5, -. voltages present

36、unless otherwise specified. ,. - “. 1-3.2.2 Commercial Equipment Sockets . . Interelectrode capacitance may be Qeasured using commercial iquipment sockets. In those cases, measurement of the capacitmce shall be taken prior to the insertion of the tube base pins into the socket. This initial reading

37、shall be subtracted from the reading made with the tube inserted, togive the- tnie capacitance between the elements under test. . - . EIA 191-D 85 = 3234b00 0028658 8 = - , EIA- 191 -D Page 7 1,3,2,3 Mrect Connectiorr to Tube Terminals In those cases where the terminals do not fit the standard socke

38、ts or cap connectors, connections shall be made directly to such terminals by using flexible shielded leads. Shielding on the connect- ing leads shall be carried as close to the terminals as possible. Shielding between terminals shall also be used, where necessary, in order to haue the capacitance m

39、easurement exclude the capaci- tance between terminals outside the base or bulb, just as is done in the case of standard shielded sockets and cap connectors. Standard Shields shall be used where specified on tube rating sheet. When used, cylindrical shields shall sit squarely on and concentric with

40、the capacitance socket. When both a shield and a cap connector are used, the cap connector shall be concentric with the opening of the shield. When measuring capacitances not requiring shields * the lower member of standard two-part shields shall be removed if this significantly affects *e measured

41、capacitance. The dimensions and shapes of the standard shields have been selected to provide for maximum repeatability of measurement, ease of use, use on largest number of tube types to keep number of standard shields at minimum, and simple shield shapes that allow for maximum allowable variation i

42、n bulb dimensions.:Therefore, the standard shields do not necessarily provide thebest shielding for an individual outline. 1.3.3 air should be at such a distance from the tube under test, that a change in the relative position between the object and the tube does not affect the capacitance reading.

43、Where shielded leads are used to make connections to the tube terminals, the leads shall be arranged to have the smallest effect on the capacit- tance measurement. 1.3.4 ductive bulb coatings, connection shall be made to the external coating by means of a conductive ring, such as braided bare wire,

44、wrapped around the bulb at a point approximately at the coating center. If the external coating has been applied in a patch so that it does not extend around the entire bulb wall, connection will then be made by means of a finger contact located at the approximate center of the coating. All metallic

45、 objects or dielectric materials having a dielectric constant appreciably greater than For cathode ray tubes, in the measurement of capacitance between the internal and external con- O 1.4 Capacitance Measuring Circuits The RF bridge method, the transmission method and an audio frequency method shal

46、l be the standard methods of measuring interelectrode capacitances with the exceptions noted below. The first two methods are basi- cally thoseshown in the IEEE Standards on Electron Tubes: Methods of Testing, 1962 (IEEE Publication 158). Capacitance measurements shall be made at test frequencies co

47、vering the range from 1 to 500 kilohertz. For the audio frequency method, the operating frequency shall be in the range from 1 to 20 kilohertz. For the RF bridge and the transmission methods, the operating frequency shall be in the range from greater than 20 to 500 kilohertz, For cathode ray tube ex

48、ternal coating to anode capacitances, measurements on an impedance bridge operating at 1 kilohertz shall be considered the standard method. When measurement is to be made of a relatively low value of capacitance in the presence of a much larger value shunting capacitance in the same electron tube (L

49、e., a ratio of 1 :200 or higher of the value to be measured to the shunting capacitance), it shall be permissible and may be preferable to use the audio 1-20 kHz frequency for best accuracy. . 1.4.1 Rddio-Frequency-Bridge Method A bridge circuit for the measurement of direct interelectrode capacitances of a tube is shown in Figure 1. A stable oscillator, such as a crystal-controlled oscillator, supplies r-f power through a closely coupled balanced transformer (T). Balance is indicated by a null4ndicating vacuum-tube volt