1、EIA CB4 b5 = 3234600 OOOOL2 2 Y -. FEBRUARY 1065 COMPONENTS BULLETIN No. 4 EFFECT OF THE WIRE DIAMETER ON WIREWOUND RESISTORS RELIABILITY Engineering Department ELECTRONIC INDUSTRIES ASSOCIATION EIA CB4 65 m 3234600 OOOOL3 4 m NOTICE EIA Engineering Standards and Publications are designed to serve t
2、he 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 the proper product for his particular need. Existence of such Standard
3、s and Pub- lications shall not in any respect preclude any member or non-member of IA from manufacturing or selling products not conforming to such Standards and Publications, nor shall the existence of such Standards and Publications preclude their voluntary use by those other than EIA members, whe
4、ther the standard is to be used either domestically or internationally, Recommended Standards and Publications are adopted by EIA 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 patent
5、owner, nor does it assume any obligation whatever to parties adopting the Recom- mended Standard or Publication. Published by ELECTRONIC INDUSTRIES ASSOCIATION Engineering Department 2001 Eye Street, N.W. Washington, D.C. 20006 PRICE: $4.00 Printed in U.S.A. EIA CBq b5 W 323qbOO OOOOL94 b EFFECT OF
6、THE WIRE DIAMETER ON WIREWOUND RESISTOR RELIABILITY AS JUDGED BY ENVIRONMENTAL AND LIFE TEST RESULTS INTRODUCTION For many years the question of the minimum wire size which could be safely used for wirewound resistors has been debated. In Military specifications the minimum wire diameter has been sp
7、ecified which indicated that below that diameter unsatis- factory operation could be expected. Many hours have been spent discussing whether the minimum should be 0.00175“, O.OOl5“, 0.001“, 0.0008, or some other size. Opinions on this requirement havevaried greatly between wirewound resistor manufac
8、turers, and between persons who have con- ducted tests to obtain an answer to the problem. To obtain an Industry-wide solution, the EIA WorMng Group P-1.4 on Wirewound Resistors has conducted an Industry-wide testing program. A total of eight wirewound resistor manufacturers participated and a total
9、 of 2400 resistors were tested. Three types of resistors were included in the test. The companies participating for each type are shown below. POWER WIREWOUND RESISTOR Characteristic G per Mil-R-26C Dale Electronics, Inc. International Resistance Co. P.R. Mallory of nits in each group) “Open“ - +2.0
10、0% but not open - +LOO$ to - +1.gg$ 1 I - +0.75% to +0.99% I 11 J I - +o. 25% to c +O. 49% - +O. 50% to - +O. 74% - +0.10$ to - +0.24$ 10 - 12 +O. 05% to +O. 09% 1 2. - - 0.00% to - +O.Ob% 48 46 TOTAL UNITS REPORTED 1 60 60 o) - +0.10$ to -_ +0.24$ 10 12 I 1 Il 1 1 O. 00% to +O TOTAL UNITS REPORTED
11、2. ,., . _. 3 .I . 40 59 95 . 240 240 240 . -. - . . .- . . . . ., . . ._ . . CHARACTERISTIC G. . I . .- LOAD LIFE - 2000 Hour Measurement . ._ . ._-. . .: . 2 I , .I. f .i . 9 :.:i :*: . . r . . . .- . :i .: - ., . . L . . .i . . c . . . . . . . I . . . .L .i . *s.; ?. . . -_ . i:. . 1: - 20 - PROB
12、LEM HARD COPY ./ EIA CB4 65 3234600 0000214 8 SHORT Resistance Change Absolute Highest Percent Average Maximum Percent a- Average Algebraic Mean Percent Average Absolute Mean Percent Frequency Distribution “Open I +2.OOp -1 but not open (Number- of units -in each group) - +LOO$ to - +i.&$ - +0.75% t
13、o 50.99$- +o. 50% to +o. 74% I - - - +0.25$ to - +O.$ - +O.O$ to - +0.24% - +0.05$ to 20.09% . 0.00% to - +0.04$ TOTAL UNITS REPORTED TIME OVERLOAD Wire Size o. 0012* o. 0009 o. O006 o, 030 O. 040 O. 040 o. OO.( 0.014 o. 020 n nnu n nnh n nnn O. 004 o. 008 0.011 rr. VV I V. VVY V. VV“ 59 60 60 59 60
14、 60 0, - 21 - TEMPERATURE CYCLING Wire Size Resistance Change o. 0012“ o 0009 o. 0006 0.020 o, 100 0.050 Average Algebraic Mean Percent -0.001 -0.016 -o. 003 Average Absolute Mean Percent o. 005 0.016 . o. 005 Absolute Highest Percent Average Maximum Percent o. 009 O-. 023 O. 017 Frequency Dis tribu
15、tion Open“ - +2.0076 but not open (Number of units in each group) - +LOO% to - +1.gg$ - +o. 75% to o:gs$ - +o. 50% t - +o. 74% “ - +0.25$ to - +O.&$ - +O.O$ to - +0.24$ - +o.o5$ to - +0.09$ 1 0.00s to - -1-0.04% 59 60 59 J TOTAL UNITS REPORTED 59 60 60 b EIA CB4 65 W 3234b00 0000215 T W . . ,. EIA C
16、B4 65 m 3234600 O000216 1 MOISTITRE RESISTANCE Resistance Change AbsoLute Highest Percent Average Maximum Percent Average Algebraic Mean Percent Average Absolute Mean Percent Frequency Distribution “Open II I - +2.00$ but not open (Number of units in each group) - +LO% to - +1.g% - +o 75% to -.99$ -
17、 +0.25$ to - +0.4% - +o.os$ to - +o.og$ O.O$ to - +0.04% - +O, 50% to - +O. 74% - +O.los to - +0.24% TOTAL UNITS REPORTED *Based on EOUT companies . PRECISION WIREWOUND RESISTOR TYPE - 20 Day Measurement* Wire Size .e 2 o. 0009 o 0006 0.025 o. 052 0.334 o * 011 0.w O. 140 0.002 .o.oos o. 010 O. 004
18、O . OQ( 0 9 o39 1 8 1 1 40 39 30 40 40 40 only. Maximum Mean INSULATION RESISTANCE* . Resistance . I Megohm 1 81,666 . 39,333 - I Minimum 5,20 i *Bsed on four cgnpanies only. I I - 23 - EIA CB4 b5 9 3234b00 0000217 3 9 - w.wp DUC noz open , - .- - +LO to - +l.gg$ +0.75% to +0.9% - +O.SO$ to - +0.74$
19、 .- +0.25%.to c +O.$ ,. - - . . - +0.10$ to - +0.24$ +o.os$ to - +o.og$ . 0.00% to.20.04$ , . - TOTAL UNITS ,mPORTED c , ._ . ._ 7 5 3 ,_ 5 9 -7 230 228 224 240 240 = - 240 .- o _- Wire Size Resistance Change 010012 O. ooog, o . 0006 , * 0.110 O? 00 Absolute Highest Percent. Average Maximum Percent
20、O. 048 Average Absolute Mean Yercent o. 01 O. 033 0.015 . 1. o LOS 0.23b Average Algebraic Mean. Percent 0.012 o. 022 3.012 brequency Distribution . 1 .(,Shorted) (Number .of units in each group) Open It +O.OS$ to iO.O9$ 0.06 to - +0.04$ - /o 39 8 228 192 230 O TOTAL UNTTS REPORTED I I 240 I 240 240
21、 I EIA CB4 65 m 3234600 00002L 5 m LOAD LIFE - 1000 Hour Measurement P Wire Size - Resistance Change o. 0012 o. 0009 O. 0006 Absolute Hi-ghest Percent 0,250 . . 1. i loo 3.110 Average Maximum Percent o. 113 0.315. O. b33 n nm ?U Average Algebraic Mean Percent 0.02b v. vi-Y Average Absolute Mean Perc
22、ent o ,o27 O. 041 0.052 v “J I - Frequency Distribution. “Open“ 2 (Shorted) (Number of units in each group) - +2.00% but not open - +LOO$ to - +1.gg% +o. - 75% to AO* 99% - +O. 50% to +O. - 74% 1 - +O. 25s to +O. 49% 1 3 - +0.10$ to - +0.24$ 1 16 -., 5 - +o.os$ to - +o.og$ 20 42 9 2 I 0 O.O to - +0,
23、04$ 218 178 221 h TOTAL UNITS REPORTED 240. . 240 , 240 PRECISION WIREWOUND RESISTOR TYPE f LOAD LIFIE - 500 Hour Measurement* - c1.00% to - +i.gg$ - +0.75$ to - +o.gg$ +0.50$ to +0.74$ I - - +O. 25% to +O. 49% I - - I- LI I . I - +O. 10% to - +0.24% I . 31 l3 I 5 - +O. 05% to - +O. 09% 33 . I 6 I I
24、 I 0.0%-to - -1-0.04$ I 190 I 153 I i86 I I, TOTAL UNITS REPORTED 200 I - 200 1 200 o Based on five companies only. - 25 - EIA CB4 65 = 3234600 00002LCl 7 . , .1. -i .7. J . . . . . ._ = . ._. . . . -. . . - . . -. a *%sed on five companfes only, . . . -. -. .- . : . . ., :* .- . n. . I. . . -,. .1
25、_. . ., . i . - -. . *. . ,. . -. . -1. e EIA CB4 65 3234600 O000220 3 w 0 z Q -?- 4 3 2 I O EIA FINE WIRE EVALUATION PROGRAM PER MIL-R-93C PRECISION WIR E WOUND RES ISTORS I I I NUMBER OF UNITS THAT EXCEEDED f0So/o RESISTANCE CHANGE I NONE OF THE 120 UNITS (4 LOTS) CHANGED MORE THAN k0,5/0 DURING (720 UNITS, 6 LOTS) IFE - 2000 HRS. ITS, 5 LOTS) I ABSOLUTE MEAN PERCENT RESISTANCE CHANGE .I 2 UNITS “SHORTED! LOAD LIFEr2000 HRS. NOT INCLUDED -MOISTURE TEST- 20 DAYS 0.0012 INCH O.OO9 INCH 0.0006 INCH WIRE DIAMETER WIRE DIAMETER WIRE DIAMETER - 27 - -. o
