3.15 L: Inductor
3.15.1 Syntax
Device
Lxxxxxxx n+ n– value
Lxxxxxxx n+ n– expression
Lxxxxxxx n+ n– value
{IC=initial-current}
.inductor label n+ n– expression
Model (optional)
.model mname TABLE {args}
3.15.2 Purpose
Inductor, or general flux storage element.
3.15.3 Comments
N+ and n– are the positive and negative element nodes,
respectively. Value is the inductance in Henries.
The (optional) initial condition is the initial (time = 0) value of
the inductor current (in Amperes). Note that the initial conditions
(if any) apply only if the UIC option is specified on the transient command.
You may specify the value in any of these forms:
- A simple value. This is the inductance in Henrys.
- An expression, as described in the behavioral modeling chapter. The
expression can specify the flux as a function of current, or the
inductance as a function of time.
- A model, as described in the behavioral modeling chapter. The
table model describes a table of flux linkages vs. current.
3.15.4 Probes
The following probes (Transient, DC, and OP analysis) are available in
addition to those available for all basic elements. See the print command for documentation.
- DT
-
Time step. The internal time step used for this device for numerical
integration. It is not necessarily the same as the global time step.
- TIME
-
Time. The time of the most recent calculation of this device. It is
not necessarily the same as the global time.
- TIMEOLD
-
The time of the previous calculation of this device. It is not
necessarily the same as the global time.
- TIMEFUTURE
-
The latest recommended time for the next sample, as determined by this
device. The actual time will probably be sooner than this.
- DTREQUIRED
-
The required approximate maximum time step, usually based on
truncation error estimation.
- FLUX
-
The flux linkages stored in this inductor, in Weber-turns.
- INDUCTANCE
-
The effective inductance of this device. For a fixed inductor, it
be its value. For a nonlinear inductor, it is the effective
inductance at this time, or ∂ ϕ / ∂ v.
- DLDT
-
The time derivative of inductance. For a linear inductor it will be
zero.
- DL
-
The change in inductance compared to the previous sample. Its
primary use is in debugging models and numerical problems. For a
linear inductor it will be zero.
- DFDT
-
The time derivative of flux. Hopefully this is the same as voltage,
but it is calculated a different way and can be used as an accuracy
check.
- DFLUX
-
The change in flux linkages compared to the previous sample. Its
primary use is in debugging models and numerical problems.