Electro-Pneumatic Circuit Simulator
Drag & Drop • Dual-Domain • 51 Components • Solenoids • Relays • Sensors — Simulate • Explore • Practice • Quiz
1 Overview
Welcome to the Electro-Pneumatic Circuit Simulator — a free, browser-based Festo-style dual-domain simulator that combines electrical control circuits with pneumatic power systems. Designed for engineering students, automation technicians, vocational instructors, and maintenance engineers, this tool teaches how 24V DC electrical signals control pneumatic actuators via solenoid valves, relays, timers, and sensors. Build, simulate, and learn complete electro-pneumatic circuits — no installation, no signup, no licensing fees.
2 Dual-Domain Architecture & Air Cycle
This simulator operates across two domains simultaneously, just like real Festo and SMC industrial equipment:
- Pneumatic domain (cyan): compressed air flows from compressor → tank → FRL → valves → cylinders. Exhaust exits through silencers to atmosphere.
- Electrical domain (orange): 24V DC signals flow from power supply through switches, relays, and timers to solenoid valve terminals (Y+/Y−).
- Cross-domain link: solenoid valves (5/2 Single Sol., 5/2 Double Sol., 3/2 Solenoid) have both pneumatic ports and electrical terminals built in. When 24V reaches the Y+/Y− terminals, the valve spool shifts — no separate linking needed.
3. Getting Started
Select components from the collapsible palette on the left. The palette has 11 pneumatic categories (39 components) plus an Electrical Control category (12 components). Click a component to auto-place or drag it onto the canvas. Click cyan port circles (pneumatic) or orange port squares (electrical) to create connections. The simulator enforces domain separation — you cannot connect an electrical port to a pneumatic port.
4. Complete Air Cycle
Every pneumatic circuit should follow the standard Festo air path:
- Air Supply (compressor) → generates compressed air at set pressure
- Air Tank (receiver) → stores air, buffers pressure drops during demand
- FRL Unit (filter-regulator-lubricator) → cleans, regulates, and lubricates air
- Directional Control Valve (5/2 solenoid) → routes air to cylinder ports
- Cylinder (actuator) → converts air pressure into linear motion
- Silencers on exhaust ports → reduce noise as air vents to atmosphere
In pneumatics, exhaust air is vented to atmosphere (unlike hydraulics where oil returns to a tank). The silencers represent the end of the air cycle.
3 Component Library (51 Components)
Pneumatic Components (39)
Air Supply (2): Compressor and receiver tank. Air Treatment (3): Filter, regulator, FRL unit. Directional Valves (12): 2/2 on/off, 3/2 (push button, roller, idle return, plunger, solenoid), 5/2 (single solenoid, double solenoid, pilot), 5/3 (closed/exhaust center), 4/3. All DCVs show ISO 1219 internal arrows. Flow Control (3): One-way flow control, throttle, quick exhaust. Pressure Control (2): Relief valve, sequence valve. Logic (3): Check, shuttle (OR), AND valve. Actuators (4): Single-acting, double-acting, rodless cylinder, rotary actuator. Vacuum (2): Venturi generator, suction cup. Timing (2): On-delay, off-delay pneumatic timers. Measurement (3): Pressure gauge, flow meter, proximity sensor. Utility (2): Silencer, T-connector.
Electrical Components (12)
| Component | Function |
|---|---|
| 24V DC Supply | Power source for all electrical components |
| Push Button (NO) | Normally open — passes current only when pressed. Click during simulation to toggle. |
| Push Button (NC) | Normally closed — passes current until pressed (used for Stop buttons). |
| Toggle Switch | Latching on/off switch. Click to toggle state. |
| Relay (SPDT) | Coil (A1/A2) + changeover contact (COM/NO/NC). When coil energises, COM connects to NO. Supports self-holding circuits. |
| Timer Relay (On-Delay) | Contact closes after adjustable delay (0.5–30s) once coil is energised. Resets when coil de-energises. |
| Timer Relay (Off-Delay) | Contact stays closed for adjustable time after coil de-energises. |
| Pressure Switch | Pneumatic P-In port + electrical COM/NO. Closes when pneumatic pressure ≥ threshold. Must connect P-In to a pressurised pneumatic line. |
| Limit Switch | Closes when linked cylinder reaches trigger position (default 90%). Auto-detects nearest cylinder, or set “Linked Cyl ID” in properties. |
| Indicator Lamp | Lights up (green/red/yellow) when energised. Use for status feedback. |
| Emergency Stop | NC contact — breaks circuit when tripped. Click to trip/reset. Always wire in series with main power line. |
6. How Solenoid Valves Work (Festo Style)
In this simulator, solenoid valves (5/2 Single Sol., 5/2 Double Sol., 3/2 Solenoid) have built-in electrical terminals (Y+ and Y−) shown as orange square ports. You do not need a separate solenoid coil component — the coil is integrated into the valve, just like real Festo equipment.
- Wire 24V from the power supply through switches/relays to the valve’s Y+ terminal
- Connect the valve’s Y− terminal back to the power supply 0V
- When 24V reaches Y+, the valve spool shifts (energised position)
- When power is removed, the spring returns the valve to normal position
4 Pre-Built Circuits & Simulation
Each circuit includes the complete pneumatic air path (Compressor → Tank → FRL → Valve → Cylinder + Silencers) and the electrical control circuit:
| Circuit | Description | How to Test |
|---|---|---|
| Direct Solenoid | Push button (NO) directly energises 5/2 valve solenoid | Click PB to extend, click again to retract |
| Self-Holding | Relay K1 latches via its own NO contact feeding back to coil. Start (NO) to latch, Stop (NC) to unlatch | Click Start → cylinder extends and holds. Click Stop → retracts |
| Auto Return | PB extends cylinder. Limit switch at 90% extension lights indicator lamp | Click PB → extend → lamp lights green at full stroke |
| Pressure Dep. | PB energises valve A. Pressure switch on cyl A line (≥4 bar) triggers valve B | Click PB → cyl A extends → pressure switch closes → cyl B extends |
| Time Delayed | Hold PB to energise on-delay timer coil. After 3s delay, timer NO closes → valve energises | Hold PB for 3 seconds → cylinder extends after delay |
| Two-Hand Safety | Two relays with NO contacts in series. Both PBs must be pressed simultaneously | Press both PBs → cylinder extends. Release either → retracts |
| Sequential A+B+ | PB → cyl A extends. LS-A triggers cyl B. LS-B lights indicator | Click PB → A extends → B extends → lamp lights |
| Emergency Stop | E-stop (NC) in series with all power. Lamp goes dark when tripped | Click PB → extend. Click E-stop → everything de-energises |
8. Running Simulations
Press Run Circuit to start. The simulator validates your circuit and warns about common mistakes (missing air supply, unconnected pressure switch, etc.). During simulation:
- Pneumatic flow: animated blue particles show air flowing from supply through valves to cylinders
- Electrical signals: orange wires glow bright when energised, dim/dashed when off
- Click switches: push buttons (NO/NC), toggle switches, and E-stop can be clicked during simulation
- Solenoid valves shift automatically when their Y+/Y− terminals receive 24V
- Sensors respond: limit switches detect cylinder position, pressure switches detect line pressure
- Readouts: supply pressure, flow rate, cylinder force/speed, supply voltage, active solenoid count
9. Component Manipulation
- Rotate: Select + R or Rotate button for 90° clockwise rotation
- Duplicate: Right-click → Duplicate, or D
- Delete: Delete or Backspace
- Undo: Ctrl+Z
- Properties: Select a component to view/edit its parameters (pressure, delay, threshold, etc.)
5 Explore, Practice & Quiz
Browse 14 electro-pneumatic concepts across four categories: Fundamentals (electro-pneumatic basics, solenoid operation, relay logic, sensor types), Components (5/2 single & double solenoid, pressure switch, timer relay), Circuits (self-holding, auto-return, sequential, emergency stop), and Applications (pick & place, pneumatic press with safety). Each concept includes formulas, worked examples, diagrams, and practical tips.
11. Practice Mode
Solve 12 types of randomised problems: solenoid coil power (P=V×I), cylinder force with back-pressure, air consumption per cycle, timer delay settings, pressure switch thresholds, cable sizing, friction force, cycle time, compressor capacity, relay power, cylinder speed, and energy consumption. Step-by-step solutions provided.
12. Quiz Mode
5 randomly selected questions from a pool of 15 (mix of multiple-choice and numeric). Covers solenoid valve port numbering, relay self-holding, pressure switch function, timer types, E-stop safety requirements, force calculations, and solenoid power.
6 Canvas Tools, Zoom/Pan & Annotations
Annotation Toolbar
The mark bar above the canvas provides drawing and annotation tools:
- Move/Select (✥): Default mode. Click annotations to select, drag to move, corner handles to resize.
- Sketch (✏): Freehand drawing with pressure sensitivity. Choose color and width from the dropdown. Stays active after each stroke for continuous drawing.
- Shape (▭): Draw rectangles, circles, ellipses, arrows, lines, double arrows, or text labels. Shapes auto-exit to Move mode after drawing.
- Clear (🧹): Clear all annotations, sketches only, or shapes only.
- Toggle (👁): Show/hide all annotations without deleting them.
Zoom & Pan
- Ctrl + Scroll Wheel: Zoom towards cursor position
- Pinch (touch): Two-finger pinch to zoom and pan simultaneously
- Zoom toolbar (bottom-left): +/− buttons, pan mode toggle, reset view, fit all components
- Pan mode: Press H or right-click empty canvas to toggle. Drag to pan. Press Esc to exit.
- Ctrl + Drag: Pan without entering pan mode
Fullscreen
Click the ⚶ button (top-right of canvas) to enter fullscreen mode with the full palette, toolbar, and readouts visible. Press Esc or click ✕ to exit.
Export
Click the 📷 button (bottom-right of canvas) to export the current canvas view as a PNG image with watermark.
7 Shortcuts & Tips
| Key | Action |
|---|---|
| Ctrl+Z | Undo last action |
| R | Rotate selected component 90° |
| D | Duplicate selected component |
| Delete / Backspace | Delete selected component or connection |
| Escape | Exit pan mode / cancel connection / close dialog |
| Space | Toggle simulation run/stop |
| H | Toggle pan mode (drag to pan) |
| Ctrl++ | Zoom in |
| Ctrl+− | Zoom out |
| Ctrl+0 | Reset zoom and pan |
| Ctrl+1 | Fit all components in view |
| Right-click (empty area) | Toggle pan mode |
| Ctrl+Scroll | Zoom towards cursor |
Tips & Best Practices
- Always build the complete air path: Compressor → Tank → FRL → Valve → Cylinder → Silencers
- Always include an Emergency Stop (E-stop) in series with the main 24V power line
- Use indicator lamps after the E-stop — they should go dark when E-stop is tripped
- For latching circuits, use self-holding relays: wire K1 NO back to K1 A1 (coil), with a Stop button (NC) in series
- Connect the pressure switch P-In port to a pressurised pneumatic line — it won’t work without a pneumatic connection
- Set Linked Cyl ID on limit switches for reliable detection, or place them near the target cylinder for auto-detection
- Use normally-closed (NC) contacts for safety functions — the circuit fails safe if a wire breaks
- Add silencers to all valve exhaust ports to reduce noise
- Use meter-out flow control (not meter-in) for smooth cylinder speed control
- Standard industrial settings: 6 bar pneumatic supply, 24V DC electrical supply
Electro-Pneumatic Circuit Simulator — Build and Learn Industrial Control Systems Online
This free electro-pneumatic circuit simulator lets you design, build, and simulate dual-domain circuits that combine electrical control with pneumatic power — directly in your browser. With 51 drag-and-drop components spanning both domains, you can construct complete industrial automation circuits using solenoid valves, relays, timer relays, sensors, push buttons, and all standard pneumatic actuators. Watch how electrical signals flow through relay logic to energise solenoid coils, which in turn shift directional control valves and drive pneumatic cylinders. This electro-pneumatic trainer provides hands-on experience with the same circuit topologies used in real-world manufacturing, packaging, and assembly automation.
What is Electro-Pneumatic Control?
Electro-pneumatic control is the industry-standard method for operating pneumatic actuators in modern automation. Instead of using pneumatic pilot signals to shift valves (as in pure pneumatic control), electro-pneumatic systems use a 24V DC electrical control circuit to drive solenoid-actuated valves. The electrical circuit handles all the logic — push buttons initiate actions, relays implement self-holding and interlocking, timer relays provide time delays, and limit switches detect cylinder positions. The pneumatic circuit provides the power — compressed air at 4–8 bar flows through directional control valves to extend and retract cylinders. This separation of control (electrical) and power (pneumatic) offers significant advantages: faster signal transmission over long distances, easier implementation of complex sequential and safety logic, seamless integration with PLCs and industrial sensors, and standardised wiring practices per IEC 61131.
Key Components in Electro-Pneumatic Systems
The solenoid valve is the bridge between the electrical and pneumatic domains. A solenoid coil converts an electrical signal into a magnetic force that shifts the valve spool, redirecting compressed air to the desired actuator port. Single-solenoid 5/2 valves use a spring return and are the most common in simple circuits, while double-solenoid 5/2 valves remain in their last switched position (memory function). Relays are the workhorses of the control circuit — they amplify and distribute signals, implement self-holding (latching) logic, and provide multiple contacts from a single input. Timer relays add time-based control, enabling on-delay (wait before acting) and off-delay (act then wait) sequences. Limit switches and pressure switches provide feedback from the pneumatic domain back into the electrical control circuit, enabling automatic sequencing and pressure-dependent operations. Emergency stop buttons are mandatory safety devices that instantly de-energise all solenoids, causing spring-return valves to exhaust cylinders to a safe position.
Who Uses This Electro-Pneumatic Simulator?
This simulator is designed for engineering education (Technical and Vocational Education and Training) students studying mechatronics, industrial automation, and fluid power technology. Vocational instructors use it as a classroom teaching tool to demonstrate relay logic, solenoid valve operation, and safety circuit design before students work with physical equipment. Maintenance engineers use it to plan and troubleshoot electro-pneumatic circuits in production lines. Automation engineers prototype new control sequences and verify logic before commissioning. The four learning modes — Simulate (build and run circuits), Explore (study concepts and theory), Practice (solve calculation problems), and Quiz (test your knowledge) — provide a comprehensive educational pathway from understanding individual components to designing complete automated systems. With 8 pre-built template circuits ranging from basic direct solenoid control to multi-cylinder sequential operations with emergency stop, learners can progressively build their expertise in industrial electro-pneumatic circuit design.
Explore Related Simulators
If you found this electro-pneumatic circuit simulator helpful, explore our Pneumatic Circuit Simulator for pure pneumatic control circuits, Hydraulic Circuit Simulator for high-pressure fluid power systems, Ohm's Law Simulator for fundamental electrical calculations, and DC Motor Simulator for electric motor characteristics and control.