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引用第3楼sinian519于2007-08-31 16:48发表的 :
) F. h& @) g H9 p我也不是很熟悉,请看标准UL153,Clause140.2
: k5 ?7 T5 S5 ]' g根據這個圖就對了.
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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:
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140.2.5 The measurement circuit for leakage current is to be as illustrated in Figure 140.1. The! J& R! l1 u, D, [
measurement instrument is defined in (a) – (c). The meter that is actually used for a measurement is' K" F3 P/ X! v) _: o
required to only indicate the same numerical value for a particular measurement as the defined& o. g, j# k" B' Z
instrument. The meter used is not required to have all the attributes of the defined instrument.
2 x7 N+ ?: L9 P3 n$ e- J, ca) The meter is to have an input impedance of 1500 ohms resistive shunted by a capacitance
/ _' P! G' o9 G5 f' i7 c9 Fof 0.15 microfarad.
, n; l0 k5 |% M& xb) The meter is to indicate root mean square values which is 1.11 times the average of the fullwave8 o& F3 W* E! r2 a# r; t/ n* R
rectified composite waveform of the current through the resistor.
0 R% B$ Z8 Z0 ^4 H! h, k# rc) Over a frequency range of 0 – 100 kilohertz, the measurement circuitry is to have a
& T& _! b& q8 U' sfrequency response – ratio of indicated to actual value of current – that is equal to the ratio of
7 ` {: i% N; `8 q. X8 B7 W1 vthe impedance of a 1500 ohm resistor shunted by a 0.15-microfarad capacitor to 1500 ohms. At# Y" h _( X: s1 \+ c
an indication of 0.5 milliamperes, the measurement is not to have an error of more than 59 g- M+ L) ~" u5 ]( i0 e
percent at 60 hertz. |
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