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很想知道你们用示波器抓的是哪里的频率,是不是抓跨接在初次级Y电容上的频率?
; |; h! i5 j* m$ W9 e一般,SMPS变压器及次绕组都会经历50kHz以止的频率,但此频率是不是跨接在绕阻初次级Y电容的频率呢?
4 ~9 p) h0 M$ r2 @5 u8 n1 vcl 2.3.2 of IEC60950-1 For frequencies above 1 kHz, the limit of 0,7 mA is multiplied by the value of the frequency in kilohertz but shall not exceed 70 mA peak.这里的频率是指哪里的频率呢?! a6 V* b4 p8 O8 i, E
For parts whose voltage, U, exceeds 0,45 kV peak or d.c., but does not exceed 15 kV peak or d.c., the circuit capacitance shall not exceed 45/U nF, where U is expressed kilovolts.这里的电容是怎么得到的。U又是怎么得到的?(在IEC 60335-1里是测电量)
5 t" }! C% i1 O9 I# U% O8 F; ?请问电量又是怎么测的呢? |
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