Getting started with the Schematic panel
Britt Espinosa
Last Update één maand geleden
Every circuit you draw in CircuitSim lives in the Schematic panel. You place parts on a grid, connect them with wires, mark the points you want to measure, and press Run. The panel handles the drawing; the netlist the simulator reads is generated for you in the background.
Open it from the row of section buttons at the top of the editor. Schematic is the first one.
The layout
The panel has four regions.
Two panel names collide here, so it is worth separating them once. The Properties button in the editor's section row opens a different panel that covers the circuit record: its name, description, tags, and sharing. The properties of a component live in the right-hand Item Properties tab inside the Schematic panel, and you reach that by selecting a part or by clicking the settings toggle in the panel top bar.
Your first result
Six steps get you from an empty grid to a plotted waveform.
Then press Ctrl+Enter (Cmd+Enter on a Mac) or click the Run button.
One thing to check before you go looking for the result: if your circuit was created with the schematic-first defaults, the Chart and Table panels start hidden. A successful run in that state looks like nothing happened. Turn on Chart in the section row at the top of the editor and the waveform is there.
The five tools
The center of the panel top bar holds five tool buttons. Each one changes what a click on the canvas does.
Auto is the tool most people leave on. It reads your pointer position and picks the right behavior, so you can drag a resistor and then draw a wire without touching a tool button.
Note that the Auto tool's tooltip advertises A as its shortcut. A opens Quick Search. There is no key that switches to Auto; use the toolbar button.
Placing components
There are five routes onto the canvas, and they suit different moments.
Quick Search is the fastest once you know it. Press A with the canvas focused, or Ctrl+Space from anywhere in the editor. Type a name, use the arrow keys, press Enter, then click to drop. It also accepts short codes:
Typing ac voltage divider places a complete AC source, two 1K resistors, and a ground in one action.
The component library on the left is for browsing. Search with the box at the top, filter by library (All components, CircuitSim, Me, Partner, Community), by tag, category, or manufacturer, and switch between grouped and flat results. Signed-in users can star a part to pin it to a Favorites section. Click a tile, then click the canvas.
Drag and drop works from the same tiles if you prefer it. This can be turned off in the circuit's Properties panel under Enable left menu drag placement, a browser-level setting rather than a per-circuit one.
Direct keys cover the two parts you place most: G arms a ground, Q drops a no-connection marker immediately at the pointer.
Paste brings in whatever you last copied, including from another circuit.
Placement is one action at a time. After you drop a part the tool disarms, so placing eight resistors means eight trips to the palette or eight rounds of Quick Search. Copy and paste is usually quicker for repeated parts.
When a part lands, CircuitSim assigns the next free reference designator for its type (R1, R2, C1), names any new net label NET1 or NET2, and runs a pass that connects pins already sitting on a wire.
Moving, rotating, and mirroring
Drag with the Select or Auto tool to move. Everything snaps to the 10-unit grid.
Rotation also works on a part you have armed but not yet placed, so you can orient a resistor before it touches the grid.
With several items selected, an arrange toolbar appears offering six alignment actions, two distribute actions, and two gap-collapse actions.
Selecting
Wiring
Start a wire from a component pin, a junction, a wire stub, or a probe tip. Each click on the canvas commits one right-angle segment. Click a pin or junction to finish the wire there. Double-click empty canvas to end it in a free-floating stub. Escape abandons the draft.
CircuitSim routes wires around obstacles as you draw. If a route comes out awkwardly, B re-routes the wire under your pointer and Ctrl+B re-routes the wires in the circuit.
Where a new wire crosses an existing one, the existing wire is split at the intersection and a junction is created. Junctions accept up to four wires, one per direction.
Net labels connect points without drawing a wire between them. Place two labels with the same name and the two nets are joined. The first label placed on a net gives that net its name.
No-connection markers (Q) tell the simulator that a pin is unconnected on purpose, which keeps it out of the warnings list.
Connection problems surface in two places. A badge in the bottom-right of the canvas counts current errors and warnings and opens the detail list when clicked. Anything found while building the netlist appears in the Info panel.
Probes
A simulation only records what you probe. Four kinds are available.
The tip of the probe is the part that matters, and it has to sit exactly on a wire. Attachment is geometric, and there is no highlight to confirm a hit, so a probe dropped a few units off looks identical to one that landed correctly. If a run gives you fewer series than you expected, check the Info panel for a message about a probe not being connected.
Each probe is named from its designator, and that name is what you see in the Chart and Table panels. Renaming a series in either of those panels renames the probe here, and the reverse is also true.
Turn on Numeric Display in a probe's item properties (or Logic Display for a digital probe) to show its live value on the canvas during an interactive run. Decimal Places sets the precision, from 0 to 6.
Navigating the canvas
Zoom runs from 0.5x to 8x. On a large schematic Zoom to extents reaches the 0.5x floor before it fits everything, so the outer edges can stay off screen.
Running and stopping
The Run button is the leftmost control in the panel top bar's right group. The analysis it runs comes from Simulation Type in the right-hand Simulation Settings tab: Interactive, Interactive Operating Point, Transient, AC Sweep, DC Operating Point, DC Sweep, and Parameter Sweep. Transient is the default.
Interactive, Interactive Operating Point, and Parameter Sweep runs can be stopped mid-flight, and the button becomes a Stop button while they are going. The other analyses run to completion and the button shows a spinner instead.
During an interactive run the canvas gets a pulsing border and a running badge, and probes with numeric display switched on show live values. The border and badge can be turned off in the circuit's Properties panel under Show interactive run indicators.
Neither the Run button nor Ctrl+Enter saves your work, so press Ctrl+S as well. Inside the SPICE panel's text editor, Ctrl+Enter does save first, which is the one place the two differ.
Exporting the drawing
The export button in the panel top bar offers Export as .png and Export as .pdf. The file is named from the circuit name. Both formats are rendered on a white background regardless of your theme.
Keyboard shortcuts
The Hotkeys button in the editor's top bar lists these in the app.
Ctrl+B does two jobs. With a label selected it toggles bold. With nothing selected it re-routes wires.
Limits and things that will stop you
Open it from the row of section buttons at the top of the editor. Schematic is the first one.
The layout
The panel has four regions.
- The canvas. The grid in the middle. Minor gridlines sit every 10 units, major lines every 100. Everything you place snaps to the minor grid.
- The component library. A collapsible panel on the left, headed Components. Closed by default on existing circuits, open on brand-new ones.
- The item and settings panel. A collapsible panel on the right with two tabs, Item Properties and Simulation Settings. This is where a selected part's value, model, and designator live, and where you pick which analysis to run.
- The panel top bar. Tools, zoom, and undo or redo in the center; Run, label tools, export, and the settings toggle on the right.
Two panel names collide here, so it is worth separating them once. The Properties button in the editor's section row opens a different panel that covers the circuit record: its name, description, tags, and sharing. The properties of a component live in the right-hand Item Properties tab inside the Schematic panel, and you reach that by selecting a part or by clicking the settings toggle in the panel top bar.
Your first result
Six steps get you from an empty grid to a plotted waveform.
- Click the canvas once. Most single-key shortcuts only fire when the canvas has focus.
- Place a source. Press A to open Quick Search, type dc, press Enter, then click where you want it.
- Place a resistor. Press A, type r, press Enter, click.
- Place a ground. Press G, then click. A ground is not optional. A run without one is refused with a message asking you to add one.
- Wire it up. Press W for the wire tool, then click a pin and click the destination pin. Press Escape between wires.
- Add a probe. Press A, type vp, press Enter, then click directly on a wire. A probe that lands next to a wire rather than on it is skipped, and the run produces nothing to plot.
Then press Ctrl+Enter (Cmd+Enter on a Mac) or click the Run button.
One thing to check before you go looking for the result: if your circuit was created with the schematic-first defaults, the Chart and Table panels start hidden. A successful run in that state looks like nothing happened. Turn on Chart in the section row at the top of the editor and the waveform is there.
The five tools
The center of the panel top bar holds five tool buttons. Each one changes what a click on the canvas does.
- Auto (no shortcut). Switches between select and wire behavior based on what you are hovering.
- Select (S). Selects and drags parts.
- Wire (W). Starts and extends wires.
- Interactive (I, or hold Alt). Operates live controls such as switches and sliders instead of moving parts.
- Delete (D). Deletes whatever you click.
Auto is the tool most people leave on. It reads your pointer position and picks the right behavior, so you can drag a resistor and then draw a wire without touching a tool button.
Note that the Auto tool's tooltip advertises A as its shortcut. A opens Quick Search. There is no key that switches to Auto; use the toolbar button.
Placing components
There are five routes onto the canvas, and they suit different moments.
Quick Search is the fastest once you know it. Press A with the canvas focused, or Ctrl+Space from anywhere in the editor. Type a name, use the arrow keys, press Enter, then click to drop. It also accepts short codes:
- r resistor, c capacitor, d diode, g ground
- dc DC voltage, ac AC voltage
- vp voltage probe, cp current probe, dp digital probe
- net net label
Typing ac voltage divider places a complete AC source, two 1K resistors, and a ground in one action.
The component library on the left is for browsing. Search with the box at the top, filter by library (All components, CircuitSim, Me, Partner, Community), by tag, category, or manufacturer, and switch between grouped and flat results. Signed-in users can star a part to pin it to a Favorites section. Click a tile, then click the canvas.
Drag and drop works from the same tiles if you prefer it. This can be turned off in the circuit's Properties panel under Enable left menu drag placement, a browser-level setting rather than a per-circuit one.
Direct keys cover the two parts you place most: G arms a ground, Q drops a no-connection marker immediately at the pointer.
Paste brings in whatever you last copied, including from another circuit.
Placement is one action at a time. After you drop a part the tool disarms, so placing eight resistors means eight trips to the palette or eight rounds of Quick Search. Copy and paste is usually quicker for repeated parts.
When a part lands, CircuitSim assigns the next free reference designator for its type (R1, R2, C1), names any new net label NET1 or NET2, and runs a pass that connects pins already sitting on a wire.
Moving, rotating, and mirroring
Drag with the Select or Auto tool to move. Everything snaps to the 10-unit grid.
- Arrow keys: nudge.
- Shift and arrow keys: nudge farther.
- R: rotate clockwise.
- Shift+R: rotate counter-clockwise.
- X: mirror across X.
- Y: mirror across Y.
- M: move the selection at the pointer, then click to drop.
- Alt+Left and Alt+Right: cycle symbol variant.
Rotation also works on a part you have armed but not yet placed, so you can orient a resistor before it touches the grid.
With several items selected, an arrange toolbar appears offering six alignment actions, two distribute actions, and two gap-collapse actions.
Selecting
- One item: click it.
- Add or remove one: Ctrl or Cmd and click.
- Marquee: hold Shift and drag on empty canvas. Plain dragging pans the view, so the Shift is required. Marquee selection picks up individual wire segments as well as parts.
- Everything: Ctrl+A.
- Clear: Escape, or click empty canvas.
Wiring
Start a wire from a component pin, a junction, a wire stub, or a probe tip. Each click on the canvas commits one right-angle segment. Click a pin or junction to finish the wire there. Double-click empty canvas to end it in a free-floating stub. Escape abandons the draft.
CircuitSim routes wires around obstacles as you draw. If a route comes out awkwardly, B re-routes the wire under your pointer and Ctrl+B re-routes the wires in the circuit.
Where a new wire crosses an existing one, the existing wire is split at the intersection and a junction is created. Junctions accept up to four wires, one per direction.
Net labels connect points without drawing a wire between them. Place two labels with the same name and the two nets are joined. The first label placed on a net gives that net its name.
No-connection markers (Q) tell the simulator that a pin is unconnected on purpose, which keeps it out of the warnings list.
Connection problems surface in two places. A badge in the bottom-right of the canvas counts current errors and warnings and opens the detail list when clicked. Anything found while building the netlist appears in the Info panel.
Probes
A simulation only records what you probe. Four kinds are available.
- Voltage probe measures a node against a reference, ground by default.
- Current probe measures current through a wire. It cuts the wire and inserts a zero-volt ammeter, so direction matters. F flips the direction of a single selected current probe.
- Digital probe records logic state rather than a voltage.
- Voltage reference sets an alternative reference point for voltage probes.
The tip of the probe is the part that matters, and it has to sit exactly on a wire. Attachment is geometric, and there is no highlight to confirm a hit, so a probe dropped a few units off looks identical to one that landed correctly. If a run gives you fewer series than you expected, check the Info panel for a message about a probe not being connected.
Each probe is named from its designator, and that name is what you see in the Chart and Table panels. Renaming a series in either of those panels renames the probe here, and the reverse is also true.
Turn on Numeric Display in a probe's item properties (or Logic Display for a digital probe) to show its live value on the canvas during an interactive run. Decimal Places sets the precision, from 0 to 6.
Navigating the canvas
- Pan: drag anywhere with any tool.
- Zoom: scroll wheel, or the zoom buttons in the panel top bar.
- Fit: the Zoom to extents button frames every part and wire, accounting for the open side panels.
Zoom runs from 0.5x to 8x. On a large schematic Zoom to extents reaches the 0.5x floor before it fits everything, so the outer edges can stay off screen.
Running and stopping
The Run button is the leftmost control in the panel top bar's right group. The analysis it runs comes from Simulation Type in the right-hand Simulation Settings tab: Interactive, Interactive Operating Point, Transient, AC Sweep, DC Operating Point, DC Sweep, and Parameter Sweep. Transient is the default.
Interactive, Interactive Operating Point, and Parameter Sweep runs can be stopped mid-flight, and the button becomes a Stop button while they are going. The other analyses run to completion and the button shows a spinner instead.
During an interactive run the canvas gets a pulsing border and a running badge, and probes with numeric display switched on show live values. The border and badge can be turned off in the circuit's Properties panel under Show interactive run indicators.
Neither the Run button nor Ctrl+Enter saves your work, so press Ctrl+S as well. Inside the SPICE panel's text editor, Ctrl+Enter does save first, which is the one place the two differ.
Exporting the drawing
The export button in the panel top bar offers Export as .png and Export as .pdf. The file is named from the circuit name. Both formats are rendered on a white background regardless of your theme.
Keyboard shortcuts
The Hotkeys button in the editor's top bar lists these in the app.
- A or Ctrl+Space: open Quick Search
- Ctrl+Enter: run simulation
- Ctrl+S: save circuit
- Ctrl+Z and Ctrl+Shift+Z: undo and redo
- Ctrl+A: select all
- Escape: cancel the current action, or clear the selection
- Ctrl+C, Ctrl+V, Ctrl+D: copy, paste, duplicate
- Delete or Backspace: delete the selection
- Arrow keys, Shift and arrows: nudge, nudge farther
- S, W, I, D: Select, Wire, Interactive, Delete tools
- G and Q: place ground, place no-connection marker
- M: move the selection at the pointer
- F: flip current probe direction
- R and Shift+R: rotate clockwise and counter-clockwise
- X and Y: mirror across X and Y
- Alt+Left and Alt+Right: cycle symbol variant
- B and Ctrl+B: auto-route the hovered wire, auto-route all wires
- Ctrl+B and Ctrl+I: bold and italic on a selected label
Ctrl+B does two jobs. With a label selected it toggles bold. With nothing selected it re-routes wires.
Limits and things that will stop you
- A ground is required. Runs without one are refused before they reach the simulator.
- Probes must sit on a wire. No probe means no data, and the warning is easy to miss.
- Component count is capped per circuit by plan. A counter in the bottom-left of the canvas shows your usage and turns amber near the limit. Probes, net labels, and grounds do not count toward it.
- Some analyses need a paid plan. A locked type shows a padlock in the Simulation Type list with the plan it needs. Choosing it and pressing Run opens the upgrade dialog rather than starting a run.
- Editing is not the same as saving. If you have view-only access to a circuit you can still move parts around, and the work is lost when you try to s
Still stuck?
CircuitSim is built by a small team and we are happy to help. Email [email protected] and tell us what you were doing and the name of the circuit or group involved. If you are talking to the chat assistant, leave your email address in the chat and one of us will reply.