Get the equivalent inductance at terminal in circuit:
Acquire the equivalent inductance at terminal AB in circuit shown in Figure.
Solution
Inductances also follow the same rule as the resistances for series, parallel and star- delta connections. Primary we convert the star connection a b c n to corresponding delta connection.
For delta connection,
L_{ab} = L_{an} L_{bn} + L_{bn} L_{cn }+ L_{cn} L_{an} / L_{cn}
= 1 + 1 + 1 /1 = 3H
Likewise, L_{bc} = 3 H and L_{ac }= 3 H
So, the circuit of Figure is redrawn as illustrated in Figures (a) and (b).
L _{eq} = 3/2 H is in parallel with 3 Henry.
So,
L_{eq} = 1.5 × 3 /1.5 + 3 = 1 Henry