3.5.3 DCEquations

Command structure of DCEquations.

Given a Transient DAEObject, DCEquations transforms the dynamic equations into a static system and returns a DC DAEObject. All derivatives with respect to the IndependentVariable (as stored in the DAEObject) are replaced by zero. The initial time is inserted into both the equations and the design point. Depending on the value of the ModeValues option, the values of independent sources stored in the DesginPoint option of the DAEObject are replaced by the corresponding DC values stored in the ModeValues option of the DAEObject.

Note that, given a Netlist or Circuit object, you can set up DC equations directly using CircuitEquations.

DCEquations provides the following options:

Options for DCEquations.

See also: ACEquations, CircuitEquations.

Options Description

InitialTime

The option InitialTime specifies the value (which can be any Mathematica expression) to be substituted for the independent variable in the equation system and the design point. If the value of the InitialTime option is set to Automatic, the initial time is extracted from the InitialTime option stored in the DAEObject. The default setting is InitialTime -> Automatic.

ModeValues

The option ModeValues specifies whether values of independent sources should be updated in the DesignPoint option of the returned DAEObject. If the value of the ModeValues option is set to Automatic, DC values of independent sources are extracted from the ModeValues option stored in the DAEObject. If the value of the ModeValues option is set to None, the values of independent sources are used as-is. Note that in both cases the initial time is inserted into the design-point values. The default setting is ModeValues -> Automatic.

Examples

Load Analog Insydes.

In[1]:= <<AnalogInsydes`

Define netlist description of a simple diode rectifier circuit.

In[2]:= rectifier = Circuit[
Netlist[
{V0, {1, 0}, Symbolic -> V0,
Value ->2. Sin[10^6 Time]},
{R1, {2, 0}, Symbolic -> R1, Value -> 100.},
{C1, {2, 0}, Symbolic -> C1, Value -> 1.*^-7},
{D1, {1 -> A, 2 -> C},
Model -> "Diode", Selector -> "Spice",
GMIN -> 0, AREA -> 1}
]
]

Out[2]=

Set up transient equation system.

In[3]:= tran = CircuitEquations[rectifier,
ElementValues -> Symbolic,
AnalysisMode -> Transient,
Value -> {"*" -> {TEMP, TNOM, $q, $k, AREA, GMIN}}]

Out[3]=

Show equation system.

In[4]:= tran // DisplayForm

Out[4]//DisplayForm=

Transform dynamic equations into a static system.

In[5]:= dc = DCEquations[tran]

Out[5]=

Show equation system.

In[6]:= dc // DisplayForm

Out[6]//DisplayForm=