Schematic editing

Place and edit components

1. Open the Schematic ribbon and choose a component. You can also use a shortcut such as R, C, L, D, V, I, or G.
2. Move the preview over the canvas. Press Space to rotate it, then click to place.
3. Select the component to edit its reference, value, Model, position, and component-specific properties in the Inspector.
4. Use the Edit ribbon or the selection's context menu for copy, duplicate, delete, rotate, mirror, and arrange commands.

Objects snap to the active grid. Choose 10, 50, or 100 mil in the View ribbon, or press Shift+G to cycle. Hold Shift while dragging for temporary 10 mil movement without changing the selected grid.

Enter component values

Values accept decimal numbers, scientific notation such as 1e-6, and these SPICE scale suffixes.

Suffixes are case-insensitive: 1M means 0.001, just like 1m. Use 1Meg for one million. For example, a 4.7 kΩ resistor is 4.7k and a 100 nF capacitor is 100n.

Annotate a schematic

Use the drawing tools in the Schematic ribbon to add lines, polylines, rectangles, ellipses, arcs, text, notes, and images. Select an annotation to edit its style and geometry in the Inspector; use theEdit ribbon to move it forward or backward in the drawing order.

• Double-click Text or Note objects to edit their content on the canvas.
• Text and Notes can show calculated component values with expressions such as {{ R3/R4 }} or {{ R3||R4||R5 }}.
• For an image, select the Graphic tool, place its frame, then upload the image from the Inspector.

Connect components

1. Choose Wire or press W, then click a component pin or an existing conductor.
2. Move the pointer. The preview remains horizontal and vertical and chooses its first elbow from the dominant pointer direction.
3. Click to lock one leg at a time, or click a terminal to finish the route.
4. Press Backspace to remove the last locked leg. Press Esc to cancel the active route; press it again to leave Wire mode.

Moving a component keeps its attached wires connected. Place a two-terminal Part directly on a straight wire to insert it into that connection.

Crossings and junctions

A bare wire crossing is not a connection. Wires connect at matching endpoints, at a pin touching a wire, or at an explicit junction. A filled junction dot identifies a real three- or four-way connection; crossing lines without that dot remain separate nets.

Starting or ending a wire on another wire creates the needed junction. This keeps a dense drawing unambiguous: you never have to infer connectivity from line geometry alone.

Name and reuse nets

• Choose Net label or press N, enter a name, and place its anchor exactly on a wire or pin.
• Labels with the same name connect their wire islands everywhere on the same sheet.
• Choose Ground or press G for SPICE node 0.
• Use Power rail for a named supply connection. ERC warns when a named rail appears to be missing its remote connection.

If one conductor has conflicting labels, ERC reports the conflict. Keep one intended name on each net.

Check ERC before simulation

The ERC chip in the document status bar opens the Console and expands Circuit checks. Select a diagnostic to understand the affected object or net.

Two pins connect directly only when their terminal endpoints coincide. Overlapping symbol lines or pin leads do not create an electrical connection.

Import and export projects

An .ohm file is the portable project format. It contains your project and its Parts so you can reopen the design in OhmSpice.

• Choose Home → Export → Export project .ohm for an offline backup or transfer.
• Choose Home → Import .ohm, review the selected file, and choose Import project.
• Signed-in import creates a new cloud project and does not link the file to an existing saved project. Importing while signed out replaces your current browser draft after you confirm.
• If OhmSpice cannot open a file, choose Save original file to keep an unchanged copy.
• Choose Export PNG from the same Export menu when you need an image of the schematic rather than an editable project.