Free Relay Diagram Maker — Draw Ladder Logic

See it work

Relay diagram examples.

Same tool, four requests. Every drawing below is a real render.

What you type

Create a sliding gate relay ladder with open and close pushbuttons, remote controls, limit switches, a safety edge that reverses closing, and open and close motor commands.

Then tryAdd an automatic close timer.Change the safety edge to a photoelectric beam.

Ladder logic · IEC 61131-3 Ladder Diagram · schematex-ladder

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The drawing

What a relay diagram is.

A relay diagram shows the control logic for an electrical circuit. Contacts represent the conditions that must be true, and a coil represents the relay or output that energizes when the rung is complete.

Ladder form reads from left to right: inputs and interlocks lead to a coil. It makes seal-in circuits, timers and safety conditions easier to inspect than a physical wiring layout.

Standard: IEC 61131-3 Ladder Diagram
Engine: schematex-ladder
Editable: Double-click text, drag nodes
Export: SVG · PNG · PDF

Who uses it

Who uses relay diagrams.

Control-panel technicians

Start, stop and interlock logic for relays in small control panels.

Maintenance teams

Timed gate and actuator controls when tracing a fault or updating a panel record.

Electrical students

Seal-in circuits and normally open or normally closed contact logic for practical training.

How it works

How to make a relay diagram in three steps.

Describe it

One paragraph is enough to start.

“Create a sliding gate relay ladder with open and close pushbuttons, remote controls, limit switches, a safety edge that reverses closing, and open and close motor commands.”

See the drawing

Drawn by the right engine.

Say what changes

Every edit keeps a version.

Add an automatic close timer.

V2 · DRAWN FROM V1, NOTHING RETYPED

FAQ

Common questions

What is a relay diagram?

It is a diagram of the control circuit around one or more relays. It shows the input contacts, relay coils, outputs and the conditions that connect them.

What do NO and NC contacts mean?

Normally open contacts are open in their resting state and close when actuated. Normally closed contacts are closed in their resting state and open when actuated.

What is a seal-in circuit?

A seal-in, or holding, contact keeps an output energized after a momentary start button is released, until a stop or fault condition opens the rung.

Can a relay diagram show safety interlocks?

Yes. Place the relevant stop, limit or safety condition in the rung so the output coil cannot energize when that condition is not satisfied.

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