Dependent Voltage Source

Description

A Dependent Voltage Source is a source with a voltage across its terminals that depends on the value of one, or more voltages or currents, elsewhere in the circuit, multiplied by a numeric ratio. The dependency can be based on voltages or currents specified by Circuit Tags, or Independent Sources. Here is a small circuit with a Dependent Voltage Source labeled "v2".

Parameters Dialog Box

The parameters of a Dependent Voltage Source are edited with this dialog box.

Label

An alphanumeric label to provide a reference to the Dependent Voltage Source.

Type of Dependency

These two radio buttons select a voltage or current dependency. A Dependent Voltage Source's dependency can be based on voltage tags and voltage sources, or it can be based on current tags and current sources.

Dependency List

This is a list of the labels of the circuit's existing Sources and Circuit Tags. The list will display voltage tags and voltage sources, or it will display current tags and current sources depending on the selected "Type of Dependency".

The list shows 'vc' (the voltage across the Capacitor in the circuit above), 'vr' (the voltage across the 5 Kohm Resistor), and 'Vs' (the voltage across the independent Voltage Source, 'Vs')

There is a '+' sign next to the label 'vc', which means that this Dependent Voltage Source's voltage is only dependent on the voltage across the capacitor, with polarity indicated by the tag 'vc'. If the label 'vc' had a '-' sign next to it then the source's voltage would be dependent on the voltage across the capacitor with the opposite polarity as indicated by the tag 'vc'. If more than one label had a sign next to it, then all these dependencies would be summed together, modified by their respective signs, to form the source's dependency.

Click the left mouse button on any label in this list to rotate the sign of the label. The sign of the label can be blank, '+', or '-'.

• If the sign is blank, then the label does not contribute to the dependency of this source.
• If the sign is '+' or '-', then the signal represented by the label is added to, or subtracted from the dependency of the source.

Dependency Coefficient

The Dependency Coefficient is a rational number formed from two real numbers. The top number is divided by the bottom number to form the coefficient which is then multiplied by the summation of the dependencies.

Therefore, the voltage across the Dependent Voltage Source, 'v2', in the circuit above, will be:

Label Position

The Dependent Voltage Source's label is initially positioned on the "Default Side" of the component. If you want, or need to change the position to improve the legibility, or layout of the circuit, you can set the position of the label to the "Other Side".