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本帖最后由 小米 于 2012-11-8 21:04 编辑 1 f8 I, H& b1 s4 z
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| | DSH 7171 x5 [; i& q! C& u- z, D! C* d
| Creepage and clearance determination, groove, recess, corner, bridging of distance X0 R; C5 @' i, d: S8 W6 {
| 4.2, 6.2
! S- D+ L. ^. R. N) i; ]% \1 i' ` | 60664-1(ed.1.2) & 60065-1(ed.2) & All equipment standards based on these
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Standard(s): No. Year
8 l! `# M5 ^ `$ zIEC 60664-1/2002 ed1.2
, d5 M* T6 b! z$ ~# ^- @IEC 60664-1/2007 ed2.0
" P( F' @; O8 Q0 d2 z- wAll equipment standards- p R) ^' v2 R Z9 X% z' r
based on these
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07179 s$ k( a% \. I2 m/ @+ Z/ r0 p
2008
, o% i. ]( G" f `0 WCategories:+ S& g! x3 L6 a: L
Various, General$ }, r$ a0 s/ X9 z7 ^
Subclause(s):
p% K: {. d7 S2 h2 n/ h4.2
+ I1 O, Z& ?5 H4 R# r( y* N2 N6.2
8 W- o7 w4 _" D4 A+ ]Developed by:- ~& U& K6 G# l% g
WG2 - WG4
( ]$ i( ]6 K) I# _: D# X; F3 {4 DSubject:
3 \% Q0 }! C0 i. E2 C# jCreepage and clearance7 j& P& T" h' N/ o2 g
determination, groove,
( H( {2 F! E# r; k- v0 Urecess, corner, bridging
0 k; K* y/ R, T f# \of distance X
4 ]/ T( K7 y% ?2 o K& k' hKey words:
4 P& k6 e8 h {! a# _4 r) k V# k- Creepage
! _7 k& B, I+ C6 r- Clearance
% |. s# V6 N4 e8 Q- Groove
$ v" l% l( }, @! r) f' X- Recess4 [5 |: I2 |6 K) h
- Corner1 A8 M/ V. c8 P3 V$ q! [
- Bridging of distance$ a& H" n7 G/ |. ^
X
7 v& u2 c* \7 M+ k! {Decision approved at the/ A1 \! ]) e2 C. }" p- d
2009 CTL Plenary. b* V$ G9 f) j2 U' [5 q
Meeting
9 y$ Y( |; }/ N; FQuestions:
* h3 m- X- E2 g9 `% u2 W1) How shall the examples given in IEC 60664 be interpreted for intermediate situations?
7 J0 B8 y! U% D8 v3 F2) How shall the example given below be judged correctly, based on the examples given in
8 s ]0 k5 X& ^IEC 60664-1 and based on the assumption that X = 1 mm?
$ ]; X4 n& V% L9 j1 t0,8mm' C! h; J# O+ ^- X
2 mm. i2 j; q. p# l$ z& E; A* f# J- r
PCB! u7 E: k2 r% y9 A) D$ J5 b
PCB-Track (ending on the9 }! ^8 o( J4 [
edge of the cut-out. V; |6 D0 m" |1 |4 E( i
3) When shall the sentence:5 C3 X% `% v9 N, R! a
“If the associated clearance is less than 3 mm, the minimum dimension X may be reduced to4 \8 n1 _+ C' C6 ]- ~
one third of this clearance.” be applied?
$ g$ R6 A& r7 Y! `3 l! f/ u% {Does this sentence refer to the actual clearance measured or to the minimum clearance
, e2 b# h7 H- prequired?
; j0 \- w7 u& o7 bDecisions:
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An intermediate situation not covered directly by the Standard shall be determined by! A) U# ^& X& ~% o5 o) I" @( c
considering it as an extension of the most appropriate example from the Standard. An example: T n+ `0 R) \
of the methodology is given in the Explanatory Notes to Question 2."
# F: F/ {/ w' yAd 2)
; {! l& K% i; EThe example shall be judged without any bridging of the corner in the cut-out
. D4 {1 V4 V; s1 Z j: X- R7 k creepage = 2,8 mm, no shortcut applicable.+ T$ u O' }& s: l
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The sentence shall always be applied whenever the required clearance is less than
, F4 J7 \0 {$ x R" v3 mm and the allowed reduction of the minimum dimension X shall be referred to 1/3 of the
1 [# Q6 q6 I0 P& i$ X/ Krequired minimum clearance.
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