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引用第3楼sinian519于2007-08-31 16:48发表的 :: L* y* \2 s3 |- Y
我也不是很熟悉,请看标准UL153,Clause140.2 8 f) s1 g* E# m- U/ m o
根據這個圖就對了.
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( H! m; g7 P& x6 n# R. o不過根據這個設備的要求, 發現標準存在問題, 請對照上面的圖再看此條, 一直困惑中:2 Z3 d* ]9 k4 q5 s7 B- o R/ K) q
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140.2.5 The measurement circuit for leakage current is to be as illustrated in Figure 140.1. The
8 f2 w4 u3 @& b+ }8 b* O+ xmeasurement instrument is defined in (a) – (c). The meter that is actually used for a measurement is
: i! I" N7 d) x% e2 P( @, w: U* Rrequired to only indicate the same numerical value for a particular measurement as the defined
6 ?; C( Z, g, j' einstrument. The meter used is not required to have all the attributes of the defined instrument.; k8 a0 S; R1 R! E! Q: L# k9 d& v
a) The meter is to have an input impedance of 1500 ohms resistive shunted by a capacitance
7 g* l6 V, | lof 0.15 microfarad.
& l& R! G$ z$ R* c6 x/ S' z# gb) The meter is to indicate root mean square values which is 1.11 times the average of the fullwave+ G9 e# G1 m3 @3 } G% [
rectified composite waveform of the current through the resistor.
* Z( r; k9 ?% Y8 h! s/ z6 Uc) Over a frequency range of 0 – 100 kilohertz, the measurement circuitry is to have a, L, C# W/ A p
frequency response – ratio of indicated to actual value of current – that is equal to the ratio of
$ _% Y7 A* z) F* N9 S3 Gthe impedance of a 1500 ohm resistor shunted by a 0.15-microfarad capacitor to 1500 ohms. At3 `6 J) [# P" |+ ?# A
an indication of 0.5 milliamperes, the measurement is not to have an error of more than 5) ?& i! A+ G- A+ o$ h
percent at 60 hertz. |
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