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Online emulators for circuit and system modeling

Online simulator for designing and analyzing analog and digital electrical circuits

This page is a utility for simulating the creation and modeling of an electrical circuit online with specified initial values.

Basic online circuits

Simulator Features

Everything you need to design and analyze electrical circuits in your browser

Real-Time Simulation

Results are instantly recalculated with every circuit change — currents, voltages, and power levels update without delay.

Rich Component Library

Resistors, capacitors, inductors, diodes, transistors, operational amplifiers, current and voltage sources, and dozens of other elements.

DC and AC Modes

Support for both direct (DC) and alternating (AC) current. Set amplitude, frequency, and phase — the simulator computes the full circuit picture.

Thermal Heatmap

The thermal heatmap overlay highlights overheated and cool areas of the circuit based on each element's power dissipation.

Magnetic Field

Closed magnetic field lines around every conductor following the Biot–Savart law (B = μ₀·I/2πr), with dipole loops around coils. Rings are coloured by power and move faster as the current grows.

Electric Field

Electric field lines run from plus to minus — between capacitor plates (E = U/d) and across source terminals. Line density and colour reflect voltage and power, and the direction flips with polarity in AC.

Electromagnetic Field

Energy flow along the Poynting vector (S = E×H) shown as closed wave-lines around components. At DC the lines are static; as frequency rises they are emitted and radiate outward ever more often — a vivid picture of radiation.

Oscilloscope & Graphs

The built-in oscilloscope plots real-time voltage and current waveforms at any circuit node.

Save & Export

Save circuits to a file, reload previously created projects, and share a direct link with colleagues in one click.

Digital Logic

Logic gates (AND, OR, NOT, XOR), flip-flops, counters, multiplexers, and other digital building blocks for designing digital circuits.

Connection Accuracy

Junction dots are automatically shown at every node where three or more wires meet, eliminating topology errors.

Any Device

Runs in a browser with no installation — on PC, tablet, or smartphone. Supports Chrome, Firefox, Safari, and Edge.

Learning & Experiments

A ready-made circuit collection by topic — from simple voltage dividers to amplifiers and filters. Ideal for students and teachers.

⚡ Circuit Online 
Left-click — place/select · hover over an end (◯ highlights) and drag — stretch · wheel — zoom · middle/right-click — pan · double-click — settings

Online circuit creation and simulation demonstration

Instructions: how to start simulating an electrical circuit online

1. Page purpose

This page is designed for creating and simulating electrical circuits online.
You can set initial parameters — add a voltage or current source and conductors (voltage, resistance, current, etc.) and observe how the system calculates circuit behavior in real time.

2.  Getting started

Step 1. Enter the initial data

  • Create a voltage or current source and specify their values in volts or amperes then connect them in parallel or in series with the relevant circuit section.
  • Set the resistances, capacitances, or inductances of elements if present.
  • Add wires and connect the corresponding elements.

Step 2. Add other circuit elements

  • Use the toolbar or the «Add element» buttons.
  • Select the required components:
    •  Voltmeters or ammeters, oscilloscopes
    •  Resistor
    •  Capacitor
    •  Inductor
    •  Other components
  • Wires and connections
  • Place them on the workspace.

Step 3. Connect the elements

  • Connect components with wires to form a closed loop — otherwise an error will occur.
  • Check for any breaks in the circuit — otherwise the circuit will not work.
  • Check for redundant connections (e.g., overlapping wires) which can cause calculation errors and infinite loops.

Step 4. Set simulation parameters

  • Specify the calculation mode:
    • Direct current (DC)
    • Alternating current (AC)
  • Configure frequency, amplitude, time step, and simulation duration.

Step 5. Click « Run simulation»

  • After starting you will see calculated current, voltage, and power values.
  • Some versions of the utility allow you to observe parameter change graphs over time.

 

3. Additional features

  • Save the circuit to a file or export it.
  • Share an image with friends or colleagues via the "Share circuit" button in the menu.
  • Load a previously saved circuit.
  • Step-by-step calculation analysis (for educational purposes).
  • View currents and voltages at each element.

 

4.  Tips

  • Before starting, make sure the circuit is closed — no overlapping wires, and conductors connected through proper junction points.
  • If the calculation fails — make sure that each element has its parameter values specified.
  • Try different initial values to see how they affect circuit behavior.
  • Redraw the circuit from scratch or undo the previous action via the menu or "Ctrl-Z"
  • If you have problems, contact support or use the yellow Report button at the bottom of the service
  • Use the links to navigate and search for ready-made circuits, e.g. Basic Online Circuits or Custom Circuits

 

 

This page is a utility for simulating the creation and modeling of an electrical circuit online with specified initial values.

Basic online circuits is a collection of ready-made circuits that can be used as a starting point for experiments and learning. You also have the ability to create your own circuits and share them with other users.