An inductor is a passive element designed to store energy in its magnetic field.
An inductor consists of a coil of conducting wire.
If current is allowed to pass through an inductor, it is found that the voltage across the inductor is directly proportional to the time rate of change of the current. Using the passive sign convention,
An inductor consists of a coil of conducting wire.
If current is allowed to pass through an inductor, it is found that the voltage across the inductor is directly proportional to the time rate of change of the current. Using the passive sign convention,
Inductance is the property whereby an inductor exhibits opposition
to the change of current flowing through it, measured in henrys (H).
Equation (6.18) is the voltage-current relationship for an inductor.
Figure below shows this relationship graphically for an inductor whose inductance is independent of current. Such an inductor is known as a
linear inductor. For a nonlinear inductor, the plot of Eq. (6.18) will
not be a straight line because its inductance varies with current. We
will assume linear inductors in this textbook unless stated otherwise.
The current-voltage relationship is obtained from Eq. (6.18) as
to the change of current flowing through it, measured in henrys (H).
Equation (6.18) is the voltage-current relationship for an inductor.
Figure below shows this relationship graphically for an inductor whose inductance is independent of current. Such an inductor is known as a
linear inductor. For a nonlinear inductor, the plot of Eq. (6.18) will
not be a straight line because its inductance varies with current. We
will assume linear inductors in this textbook unless stated otherwise.
The current-voltage relationship is obtained from Eq. (6.18) as
The inductor is designed to store energy in its magnetic field. The
energy stored can be obtained from Eq. (6.18). The power delivered to
the inductor is
energy stored can be obtained from Eq. (6.18). The power delivered to
the inductor is
Important Properties of Inductor:
1. Note from Eq. (6.18) that the voltage across an inductor is zero when the current is constant. Thus,
An inductor acts like a short circuit to dc.
2. An important property of the inductor is its opposition to the change in current flowing through it.
The current through an inductor cannot change instantaneously.
According to Eq. (6.18), a discontinuous change in the current through an inductor requires an infinite voltage, which is not physically possible. Thus, an inductor opposes an abrupt change in the current through it.
3. Like the ideal capacitor, the ideal inductor does not dissipate energy. The energy stored in it can be retrieved at a later time. The inductor takes power from the circuit when storing energy and
delivers power to the circuit when returning previously stored energy.
1. Note from Eq. (6.18) that the voltage across an inductor is zero when the current is constant. Thus,
An inductor acts like a short circuit to dc.
2. An important property of the inductor is its opposition to the change in current flowing through it.
The current through an inductor cannot change instantaneously.
According to Eq. (6.18), a discontinuous change in the current through an inductor requires an infinite voltage, which is not physically possible. Thus, an inductor opposes an abrupt change in the current through it.
3. Like the ideal capacitor, the ideal inductor does not dissipate energy. The energy stored in it can be retrieved at a later time. The inductor takes power from the circuit when storing energy and
delivers power to the circuit when returning previously stored energy.