Getting Started

Tutorials

Basic Circuit and Simulation


Getting Started


Welcome to PartSim! This first tutorial demonstrates some of the features of the PartSim Circuit Simulator. You’ll create a simple RC circuit, run a SPICE simulation and plot the waveforms.


Drawing a Simple Circuit

First, click and drag an AC Voltage Source from the Sources tab into the schematic area. Then click and drag a resistor, capacitor and one more resistor from the Passives tab.

You can rotate components by selecting them with a click and pressing the “R” key. You can select multiple components by dragging a box around them and then pressing “R’. Align the RC components in series.

Complete the circuit by dragging a GND symbol from the Port tab. You can copy and paste the GND symbol.

To wire your circuit, simply click on a component pin and then click on the other component pin to be connected. While moving the cursor, you can click anywhere to fix the segment of the wire.

You can adjust R1 by double-clicking its value and typing a new value. Alternately, you can double-click the component and adjust its value in a dialog box. You can also adjust C1’s value in a similar manner.

Finally, you can change the Voltage Source’s parameters by double-clicking on the source and editing its values in the dialog box. Because we’re only enabling the AC and the DC voltage sources, leave the Transient Source set to “None.”


Running a DC Bias Analysis

The first SPICE analysis to be demonstrated is the DC Bias Analysis

Click the “Run” button to open the Run Dialog box. Select DC Bias and hit “Run.” The resulting DC values for each node will be displayed on the schematic.

The DC voltage comes from Source V1. Adjust V1’s DC value by double clicking V1 to open its dialog box and change the DC value from 1V to 2V, for example. Rerun the simulation and see the results change as expected.

Although this is a simple circuit example, the DC Bias Analysis clearly shows the capacitor blocking the DC level of the source leaving 0V at R2.

If you deselect DC Bias and click “Run,” you will remove the DC results from the schematic.


Running an AC Analysis

To run an AC Analysis, return to the “Run” dialog, select AC Analysis and choose the AC Response tab.

Set the Start Frequency to 1 kHz and the Stop Frequency to 20 kHz. Hit the Run button.

To view the simulation output, go to the AC Analysis Tab at the top. The plot should show three nets: the input, mid, and output nets with their original net names.

If you hover over a net in a schematic, you can see the current net name for that net.

Double click on the net to display its name. You can change the net name directly to more useful ones like “vin”, “vmid” and “vout”. Rerunning the simulation will now show the plots with your new net names.

To view only specific nets of interest, simply select the Probe tab and click on nets “vmid” and “vout” for example. Rerun the simulation and you will see only your selected nets. The plot of the input “vin”, which doesn’t change across the frequency range, is no longer visible.