Free Advanced Circuit Simulator | Build & Test Online

Design professional-grade electronic schematics and test real-time DC physics directly in your web browser. Our Advanced Circuit Simulator features magnetic wire snapping, flexible 45-degree component rotation, live electron flow animations, and exact voltage drop calculations.

For ECE engineers, hobbyists, and students, bridging the gap between theoretical math and physical breadboards is a constant challenge. Placing an LED in reverse-bias or miscalculating Ohm's Law can destroy expensive components. Our Virtual Physics Engine provides a highly accurate, risk-free environment. Featuring a dynamic directed-graph solver, the engine maps your topology, applies Kirchhoff's Voltage Law (KVL), and instantly calculates the current and voltage drops across every component. Drop components directly onto wires to auto-splice them, rotate them to any angle, and let the magnetic wire tool connect everything flawlessly.

How to Use the Math Engine

Our simulator features a Directed Topographical Solver. Current must flow in a complete, uninterrupted circle from the power source back to itself.

1. Place a Battery: Select the Battery tool from the Top Toolbar and tap the canvas. The + symbol indicates the positive Anode where current originates.
2. Auto-Splice Components: Select the "Wire" tool and draw a large box. Select a Resistor, and drop it directly on top of the wire. The engine will automatically cut the wire and splice the component into the circuit.
3. Adjust Physics: Select the 👆 Select tool. Click on your Resistor. The HUD will appear. Change its resistance to 330 Ohms, or click Rotate 45° to mount it diagonally.
4. Read the Telemetry: While the circuit is active, click any component. The Inspector will show you the exact Current ($I$ in mA) flowing through it and the precise Voltage Drop ($\Delta V$) across it based on Ohm's Law!

Directed Physics: LED Reverse-Bias

Unlike a standard copper wire, an LED (Light Emitting Diode) is a semiconductor. It acts as a one-way valve for electricity.

Our physics engine enforces real-world polarity. The flat base of the LED triangle is the Anode (+), and the tip of the triangle is the Cathode (-). Electricity can only flow from Anode to Cathode. If you wire the positive terminal of your battery into the Cathode, the LED enters Reverse-Bias. The engine will detect this, drop the current to absolute zero, and display a warning in the Diagnostics Bar. To fix it, use the Select tool, click the LED, and click "Rotate 45°" until it faces the correct direction of electron flow.

How to Fix a Short Circuit

If you connect a wire directly from the positive side of the battery to the negative side without placing a Resistor or an LED in the path, the engine will trigger a flashing red Short Circuit Warning.

According to Ohm's Law ($I = V/R$), if Voltage ($V$) remains high but Resistance ($R$) drops to nearly zero (just a plain copper wire), the Current ($I$) mathematically spikes toward infinity. In the real world, this infinite current generates massive thermal energy, instantly melting your wires or causing a lithium battery fire. The simulator detects 0-Ohm paths and halts the flow immediately to teach proper load balancing.

Advanced Logic: BJTs & MOSFETs

Our simulator includes advanced 3-terminal semiconductor devices, which form the foundation of all modern computing and microprocessors.

• NPN BJT (Bipolar Junction Transistor): Think of this as an electronic switch. Instead of using your finger to close a mechanical switch, you apply a tiny electrical current to the middle wire (the Base). When the Base receives current, it opens a massive "gate," allowing high current to flow from the top wire (Collector) to the bottom wire (Emitter).
• N-Channel MOSFET: Similar to a BJT, but instead of relying on a tiny current at the base, it relies purely on Voltage at the Gate. MOSFETs are vastly superior for switching high-power loads (like DC motors) because they generate less heat and switch faster.

Frequently Asked Questions (FAQ)

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