Variable Resistor with Variable Parallel Capacitor
Purpose
Variable resistor with variable parallel capacitor.
Library
Nonlinear
Description
This component models a variable resistor with a variable capacitor connected in
parallel. The resistance and capacitance are determined by the continuous signals fed
into the inputs of the component. The current through this component is determined
by the equation

Therefore, the control signal for the capacitor is a vector twice as wide as the width
of the component. It contains both the momentary capacitance values and their
derivatives with respect to time:
. It is the
responsibility of the user to provide the correct derivatives.
Note
- This component is based on a current controlled voltage source. It may
therefore not be connected in parallel with other voltage sources or
capacitors.
- The control signal for the momentary capacitance values must be
continuous. Discontinuous changes will produce non-physical results.
Parameters and Dialog Box
-
Width
- The width of the electrical ports resp. the number of resistors/capacitors
represented by the component.
-
Initial voltage
- The initial voltage of the capacitor at simulation start, in volts
(V). This parameter may either be a scalar or a vector with the width of the
component. The positive pole is marked with a "+". The initial voltage default
is 0.
Probe Signals
-
Capacitor voltage
- The voltage measured across the capacitor. A positive voltage
is measured when the potential at the terminal marked with "+" is greater than
the potential at the unmarked terminal.