..对以下电路用戴维南定理进行等效,其中开路电压UOC为( ),短路电阻Req为( )。(提醒:需写出单位)
解ï¼5Ωçµé»ä¸æ çµæµãæ çµåï¼I=5/ï¼2+3ï¼=1ï¼Aï¼ã
Uoc=Uab=Uac+Ucb=5+3I=5+3Ã1=8ï¼Vï¼ã
çµåæºçè·¯ï¼å¾ä¸å¾ï¼
Req=Rab=5+2â¥3=6.2ï¼Î©ï¼ã
1)开路电压: Uoc = i*R3 - Us2;
i = Us1/(R1+R2);
2)等效电阻:Ro = R2 + R1//R2;