PLECS 2.2 Online Help

Variable Capacitor

Purpose

Variable capacitor.

Library

Nonlinear

Description

pict

This component models a variable capacitor. The capacitance is determined by the continuous signal fed into the input of the component. The current through a variable capacitance is determined by the equation

   d          d          d
i = dt (C ⋅v) = dtC ⋅v + C ⋅ dtv

Therefore, the control signal 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: [                          ]
 C1 C2 ...Cn ddtC1 ddtC2...ddtCn . It is the responsibility of the user to provide the correct derivatives. The momentary capacitance may not be set to zero.


Note 


Parameters and Dialog Box

[Picture]

Initial voltage
The initial voltage of the capacitor at simulation start, in volts (V). This parameter may either be a scalar or a vector corresponding to the implicit 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, in volts (V). A positive voltage is measured when the potential at the terminal marked with "+" is greater than the potential at the unmarked terminal.
Capacitor current
The current flowing through the capacitor, in amperes (A).