Transient Sources

Overview

Used when performing a time-dependent simulation. These components provide time-varying current or voltage sources that drive a circuit with a defined waveform over time. They are ideal sources, meaning their output is defined entirely by the specified waveform, regardless of the connected load.

There are four types of transient waveforms namely:

1. Piecewise Linear (PWL) Waveform.
   • Allows the definition of custom, non-periodic waveforms by specifying a series of time-value pairs, creating a piecewise linear signal. This is useful for complex waveforms that cannot be captured by simple sine, triangle, or square waves.
2. Sine Wave.
   • Generates a sinusoidal current or voltage signal.
3. Triangle Wave.
   • Generates a linear, periodic triangular waveform.
4. Rectangle Wave.
   • Generates a square wave with programmable high and low states, as well as on/off times.

Parameters

PWL

Name	Description	Unit
Times	A list of time points defining the waveform.	seconds
Values	A list of corresponding voltage or current values at each specified time point.	V or A
Number of Cycles	The total number of cycles of the waveform the source outputs before stopping.	-

Rectangle

Name	Description	Unit
Min Voltage/Current	The lower level of the rectangular waveform.	V or A
Max Voltage/Current	The upper level of the rectangular waveform.	V or A
Frequency	The number of cycles the waveform completes per second.	Hz
Theta1	The phase angle at which the waveform begins rising from the minimum to the maximum value.	Degrees
Theta2	The phase angle at which the waveform reaches its maximum value.	Degrees
Theta3	The phase angle at which the waveform begins falling from the maximum to the minimum value.	Degrees
Theta4	The phase angle at which the waveform returns to its minimum value.	Degrees
Number of Cycles	The total number of cycles of the waveform the source outputs before stopping.	-

Sine

Name	Description	Unit
Max Voltage/Current	The peak amplitude of the sine waveform.	V or A
Frequency	The number of cycles the waveform completes per second.	Hz
Theta	The phase angle that determines the initial position of the waveform within its cycle.	Degrees
DC Component	A constant offset added to the entire waveform, shifting it vertically.	V or A

Triangular

Name	Description	Unit
Min Voltage/Current	The lower level of the triangular waveform.	V or A
Max Voltage/Current	The upper level of the triangular waveform.	V or A
Frequency	The number of cycles the waveform completes per second.	Hz
Theta Start	The phase angle that determines the initial point within the waveform's cycle.	Degrees

Usage Instructions

tip

For instructions on adding a component to the simulation circuit, click here.

The steps below show how to configure the component effectively.

Adding Points

• Click Add Point to add individual points, each point is a time-voltage or time-current value.
• Alternatively, you can Import a list of values from an external CSV file.

Remove Entries

• Select a value from the list and left-click the cell to modify it's value.
• Use Delete Point to remove a selected entry.
• Use Clear All to remove all values from the list.

Adjust the Number of Cycles

• To adjust the number of cycles for the waveform, edit the value in the text box.

Apply the Configuration

• Once all parameters are set, click OK to save the changes.
• Click Cancel to discard any changes and close the window.