Abstract: The article firstly discusses the equivalent inductance of parallel coils, and shows the relation of the parallel coil＇ s equivalent inductance with both their coupling coefficient and their self-inductance. Second, it particular analyzes the current distribution in parallel coils. It is shown that when the coupling coefficient is rather large, the mutual-inductance is greater than one of their self-inductance, at the instant which circuit is connected, the direction of the currents in two coils would turn out to be in the opposite way, and the value of impulse current would be larger than the current of the steady state. At last, the experiments and tests are proved by the theoretical analysis.

Key words: parallel coils, coupling coefficient, equivalent inductance, current distribution