|
本帖最后由 小米 于 2012-11-8 21:04 编辑
% H6 V: b3 O& B# j5 k c
, u# w+ {- d# H8 _: H4 L | | DSH 717) `/ r) h% t) s
| Creepage and clearance determination, groove, recess, corner, bridging of distance X! d0 b7 Q. e P# R |0 _
| 4.2, 6.2
6 a" h2 k* a! [8 h, i3 Q+ @ | 60664-1(ed.1.2) & 60065-1(ed.2) & All equipment standards based on these
' M& K1 C% R4 B# \9 K$ J | ; g4 v7 M9 t& d! N" P' `
Standard(s): No. Year
! @. T8 g/ Z/ u8 ?" K, YIEC 60664-1/2002 ed1.2
; T$ h# [8 Z3 y; E3 |8 y( H0 @( aIEC 60664-1/2007 ed2.0
3 R) ^5 W$ |+ I! _8 z8 R3 AAll equipment standards, m& N1 ] x3 }) Q3 Z) |1 s
based on these% y e1 K, j0 ?" y
DSH
6 L! {6 ?/ `7 E3 H9 D h) W0717' H1 w8 M" v# `# |( g
20087 k0 Q' C. m$ f
Categories:' c1 k4 i5 H/ W# }
Various, General5 C; W/ j9 g" u, P' L6 {. j
Subclause(s):$ q/ |/ \+ @! o, k- i X, i0 i
4.2
3 w! l7 {( R' L% m! A, g6.2, ~! C1 A$ @+ |
Developed by: z; O& _. _8 p; z0 [) m
WG2 - WG48 p; M: {! X C
Subject:
7 t+ c) T: d2 QCreepage and clearance
* I* @8 E( F5 \; xdetermination, groove,* b/ Q; h4 ?5 g% }
recess, corner, bridging
( ^7 A- w* K5 ^& { Tof distance X
' U; t' @. J7 q3 @" k# BKey words:% ]7 M8 l! W9 j7 ~$ d: Z
- Creepage
1 q8 i7 ?5 e6 o5 I: ]0 s- Clearance
! G# l6 z# G( H- Groove9 ]3 J# J7 {. [6 J j7 V
- Recess7 V* V; [) G# }/ |8 n' Z
- Corner" k* C: V ?. f5 r
- Bridging of distance
$ B# l( U0 b2 OX
- k9 q( Q& E" X8 C( tDecision approved at the5 h1 n0 T7 J7 W% `7 d% ]5 l" }
2009 CTL Plenary
9 @) z, g$ c1 f' [5 tMeeting
/ p/ r5 h6 D* K. @Questions:0 \$ u8 |; j, }8 w
1) How shall the examples given in IEC 60664 be interpreted for intermediate situations?
: S0 Z& V2 l) \2 ]+ \' N( a2) How shall the example given below be judged correctly, based on the examples given in! _6 ?, j) ~. }2 d& d x
IEC 60664-1 and based on the assumption that X = 1 mm?
; _1 D3 J$ `: r0,8mm r, d) p7 q& f& ]
2 mm# h9 t! T$ g/ D+ A# [" f5 p! }! `9 s
PCB
9 I3 C# u, \; w; x2 N6 Q6 p8 NPCB-Track (ending on the
/ }/ m7 I* u( N: e; {2 Tedge of the cut-out
+ D( g' x( P& q) h3) When shall the sentence:
% l- m- M0 m. u“If the associated clearance is less than 3 mm, the minimum dimension X may be reduced to& k, S0 T- \% G
one third of this clearance.” be applied?0 R2 J9 b- p8 x- e' x1 r
Does this sentence refer to the actual clearance measured or to the minimum clearance0 ^! z* q* g' U$ f& i6 F: o
required?# V. v* p0 @& I
Decisions:
% [, }2 p+ B# U3 hAd 1)7 G8 o) K9 R1 ~9 K( s, `
An intermediate situation not covered directly by the Standard shall be determined by$ }# Q T- X* C; C
considering it as an extension of the most appropriate example from the Standard. An example
7 o: t+ Y- }3 J! `9 k7 pof the methodology is given in the Explanatory Notes to Question 2.": g k8 e: `5 M. ^ ^( r$ ^1 P" E
Ad 2)
3 Z4 f1 w+ @: _# J1 ?, [* E% lThe example shall be judged without any bridging of the corner in the cut-out* A$ @3 ^; E; X- O' r4 M! L: r
creepage = 2,8 mm, no shortcut applicable.9 B% M% B$ {& Q& c/ r) @
Ad 3)% R9 P7 ^& u3 O6 [- K6 ?! `6 I8 v+ D
The sentence shall always be applied whenever the required clearance is less than
/ N2 Z3 T# K/ W& V! d4 u3 mm and the allowed reduction of the minimum dimension X shall be referred to 1/3 of the' K3 }# o5 F' K8 u
required minimum clearance.
0 s- W# B j$ ~, e2 @8 _8 N( L& x
|
本帖子中包含更多资源
您需要 登录 才可以下载或查看,没有帐号?注册安规
x
|