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Variable Capacitor

Purpose

Variable capacitor.

Library

Electrical / Passive Components

Description

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

   d          d          d
i =--(C ⋅v) =--C ⋅v + C ⋅--v
   dt        dt          dt

Therefore, the control signal must provide the values of both C   and ddtC   in the following form: [C1 C2 ...Cn -dC1 d-C2...dCn ]
           dt   dt     dt . It is the responsibility of the user to provide the correct derivatives.

If the component has multiple phases you can choose to include the capacitive coupling of the phases. In this case the control signal vector must contain the elements of the capacitance matrix (row by row) and their derivatives with respect to time. The control signal thus has a width of 2 ⋅n2  , n   being the number of phases.


Note 


Parameters

Capacitive coupling
Specifies whether the phases should be coupled capacitively. This parameter determines how the elements of the control signal are interpreted. The default is off.
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).