Inductance and Capacitance in Series and Parallel

Equivalent Circuits
Typically, electrical components are arranged in either series or parallel, and the following provides methods of which to simplify circuit arrangements involving inductors and capacitors.

Inductance in Series

v = v1 + v2 + • • • + vn = (L1 + L2 + • • • + Ln)
di
dt
The equivalent inductance equals the sum of each inductance in series,
Leq = L1 + L2 + • • • + Ln




Inductance in Parallel
Leq   =   
1
1
L1
+
1
L2
+ • • • +
1
Ln
i = i1 + i2 + • • • + in
or,
i(t0) = i1(t0) + i2(t0) + • • • + in(t0)

For a single inductor:
i =
1
Leq
t
 
t0
v dτ + i(t0)
(Eq. 1)


Capacitance in Series
Ceq   =   
1
1
C1
+
1
C2
+ • • • +
1
Cn

v(t0) = v1(t0) + v2(t0) + • • • + vn(t0)



Capacitance in Parallel

Ceq = C1 + C2 + • • • + Cn



Related
▪ L - Inductors