Chapter 10 Magnetically coupled circuits 1 review A

Chapter 10 Magnetically coupled circuits 含有耦合电感的电路 1

review A single inductor: u 3

§ 10 -1 Mutual inductance 互感 4

1. Mutual Inductance 互感 互感磁通 （耦合磁通） the changing magnetic flux developed by one coil will link the other coil — mutual inductance 5

∵Φ 21≤Φ 11 ，Φ 12≤Φ 22 Coefficient of coupling: 耦合系数 0≤K≤ 1，the closer the two coils are, the greater the flux linkage, the higher the value of k. k < 0. 5 loosely coupled; k > 0. 5 tightly coupled. 8

K≈1 K<<1 9

2. The relationship between the voltage and current in a coupled circuit 磁 通 增 助 10

On the contrary: 磁通相消： 12

u u + + u 1 - u 2 - 14

确定互感电压的极性： Dot convention: When the reference direction for a current enters the dotted terminal of a coil, the reference polarity of the voltage that it induces in the other coil is positive at its dotted terminal. i i _ + 16

i 1 M i 2 ? u 1 L 2 u 2 ? 17

18

21

作业 22： 《电路》 P 315 P 272 12 - 12 10 -3 《 Fundamentals of Electric Circuits》: P 522 12. 32 23