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引用第3楼sinian519于2007-08-31 16:48发表的 :2 Y6 J3 n5 I5 f
我也不是很熟悉,请看标准UL153,Clause140.2
9 K& z( u. ^$ D$ P' ]根據這個圖就對了.8 t# _# I8 c& D- Y
+ W5 e+ C( s3 q0 m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:7 w0 F1 t! j9 t' V
4 t: ~2 |/ ~. ^# y. U. `140.2.5 The measurement circuit for leakage current is to be as illustrated in Figure 140.1. The
1 t0 [3 j" d% Nmeasurement instrument is defined in (a) – (c). The meter that is actually used for a measurement is
4 @5 |3 D- H) w9 P6 r3 O+ prequired to only indicate the same numerical value for a particular measurement as the defined i- H8 _1 O- r4 J! R
instrument. The meter used is not required to have all the attributes of the defined instrument.
. W4 _" {# r& N' Wa) The meter is to have an input impedance of 1500 ohms resistive shunted by a capacitance
! W: D( b/ V1 f0 Qof 0.15 microfarad.% N$ D+ e4 R$ ^4 g+ g
b) The meter is to indicate root mean square values which is 1.11 times the average of the fullwave8 r: o p% B8 ]! [! L
rectified composite waveform of the current through the resistor.
7 B. b; q6 O5 X6 V% Ec) Over a frequency range of 0 – 100 kilohertz, the measurement circuitry is to have a! U. V U* F! P7 ]
frequency response – ratio of indicated to actual value of current – that is equal to the ratio of
1 M& c3 j% j4 A Nthe impedance of a 1500 ohm resistor shunted by a 0.15-microfarad capacitor to 1500 ohms. At
; K& G4 x( m/ ]& {! E. han indication of 0.5 milliamperes, the measurement is not to have an error of more than 5; F N! j p1 Q! o, E
percent at 60 hertz. |
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