ee40 final 1

inductor

Inductor

OPPOSE THE FLOW OF AC BY temporarily storing some of the electrical energy as a magnetic field.

Consist of wire coils.

Inductance

The ability of the wire coil or loop to store energy.

abbreviated by the letter L

Inductance

is directly proportional to the number of turns of wire.

is also directly proportional to the diameter of the coil.

the longer the coil, the less the inductance𝛍o𝛍r AN2𝓵L = A = cross sectional area

N = no. of turns𝓵 = length of coil

Unit of Inductance

henry, abbreviated H, represents a potential difference of one

volt across an inductor within which the current is increasing or decreasing at one ampere per second.

Inductor in series

Without interaction

L = L1 + L2 + L3

Inductor in Parallel

L L1 L2 L3

1 1 1 1 = + +

Coefficient of coupling

specified by the letter k, is a number ranging from 0 (no coupling) to 1 (maximum possible coupling).

Two coils that are separated by a sheet of solid iron would have essentially k = 0

two coils wound on the same form, one right over the other, would have practically k = 1.

is specified by the letter M is expressed in the same units as

inductance:

Effects of mutual inductance

When two inductors are connected in series, and there is reinforcing/aiding mutual inductance between them.

Effects of mutual inductance

When two inductors are connected in series, and there is opposing mutual inductance between them.

Effects of mutual inductance

When two inductors are connected in parallel, and there is reinforcing/aiding mutual inductance between them.

L1L2 - M2L1 + L2 - 2ML =

Effects of mutual inductance

When two inductors are connected in parallel, and there is opposing mutual inductance between them.

L1L2 - M2L1 + L2 + 2ML =

Energy stored in the inductor

I2L 2 W = Joules

Example 1

a. Find L if L1 and L2 are reinforcing.

b. Find L if L1 and L2 are opposing.

Example 2

There are two coils with values L1 = 835 μH and L2 = 2.44 mH. They are connected in series so that their coefficient of coupling is 0.922, acting so that the coils oppose each other. What is the net inductance of the pair?

Thank You