Question

如图电桥电路中,已知R1=10欧,R2=30欧,R3=60欧,R4=4欧,R5=22欧,E=2.2伏,求电桥的总电流?

Answer 1

将R1R2R3(或R4R5R6)组成的三角形,用△→Y等效变换公

式,换成等效星形,其电阻为：

R1．2=R1R2/(R1+R2+R3)=10×30/(10+30+60)=3(Ω)

R1．3=R1R3/(R1+R2+R3)=10×60/(10+30+60)=6(Ω)

R2．3=R2R3/(R1+R2+R3)=30×60/(10+30+60)=18(Ω)

经串、并联其总电阻R总=11Ω

总电流为I=E/R总=2．2/11=0．2(A)