|
引用第12楼artscan于2009-03-11 16:42发表的 :
' _* O6 R6 Y9 J, s1 d# Y4 N一般是按照实际工作电压来算啊,不过确实这个地方是有不同意见的......1 g2 w+ e+ |- R9 n
灌封没有意义的... 灌封并不一定没有意义. 请看标准这段说明:
: e' B- c) C: B$ j" ^" r57.9.4Construction f).4 J: l) j i8 P: P9 F: ^1 {
CREEPAGE DISTANCES within moulded transformers are considered not to exist if it can
/ V% b7 {) y9 j& i3 L! q, Nbe shown that no gas bubbles are present and the thickness of the insulation between$ t: E) Y! ?- @# m* Q
enamelled or lacquered primary and secondary windings is at least 1 mm for reference
* N& i3 F# y/ _( ?' nvoltages U not exceeding 250 V and increased proportionally for higher reference$ b* E/ I& E. D$ @4 t" J, ^
voltages.! T9 L) o/ V: b0 X+ c+ f
如何能保证无气泡灌注是一门工艺, 似乎拍X光片检查比自己动手剧开要省力的多.
! I7 {* o# V! n" Z5 `0 J7 Z& y3 u! }% Q0 V# X
对于初次级之间的爬电距离, 变压器内部无可厚非一般是按有效值来计算, : r5 c# g5 B. s n! S* N
if Reference Vr.m.s of pri. & sec. < Vin+Vout, Cr.=8$ t) q Q# B2 G& s
else, if Reference Vr.m.s of pri. & sec. > Vin+Vout, Cr.= 8 + x(linear calculated out from Table 16.) / N) I6 v. Z1 J/ |- Q
/ j- y/ ~# z- Y' ?$ s4 G
Humble opinion only... |
|