Circuit Simulator Calculator
Analyze resistor, RC, and AC RLC circuits with interactive diagrams, voltage/current tables, and step-by-step circuit explanations.
Background
Circuit problems become easier when students can see current paths, voltage drops, equivalent resistance, phase, and energy storage. This calculator connects formulas to a visual circuit model.
How to use this calculator
- Choose a circuit type: series, parallel, series-parallel, RC transient, or AC RLC.
- Enter the source voltage and component values using the unit menus.
- Click Simulate Circuit to view the diagram, summary values, table, and explanation.
- Use quick picks to load common homework-style examples instantly.
- Copy the result or component table for notes, lab reports, and study guides.
- Check the power/safety warning when currents or component powers look unrealistically high.
How this calculator works
- For resistor circuits, it finds equivalent resistance, total current, voltage drops, branch currents, and power.
- For RC circuits, it calculates the time constant and capacitor voltage/current during charging or discharging.
- For AC RLC circuits, it calculates reactance, impedance, RMS current, phase angle, resonance frequency, and average power.
- It uses Ohm’s law, Kirchhoff’s voltage/current ideas, and standard transient/impedance equations.
- Visual diagrams are scaled for readability, so the drawing explains the relationship rather than exact physical layout.
Formula & Equations Used
Ohm’s law: V = IR
Power: P = VI = I²R = V²/R
Series resistance: R_eq = R₁ + R₂ + R₃
Parallel resistance: 1/R_eq = 1/R₁ + 1/R₂ + 1/R₃
RC time constant: τ = RC
Charging capacitor: V_C(t) = V(1 − e^(−t/RC))
AC impedance: Z = √(R² + (X_L − X_C)²)
Example Problem & Step-by-Step Solution
Example 1 — Series resistor circuit
- Choose series resistors with R₁ = 100Ω, R₂ = 220Ω, and R₃ = 330Ω.
- Add the resistances to get R_eq = 650Ω.
- Use I = V/R_eq to find the total current.
- Use V_i = IR_i to find each voltage drop.
Example 2 — RC charging circuit
- Choose RC transient mode with resistance, capacitance, source voltage, and time.
- Calculate the time constant using τ = RC.
- Use V_C(t) = V(1 − e^(−t/τ)).
- Read the graph to see how capacitor voltage approaches the source voltage.
Example 3 — AC RLC circuit
- Choose AC RLC mode and enter RMS voltage, frequency, resistance, inductance, and capacitance.
- Calculate X_L = 2πfL and X_C = 1/(2πfC).
- Find impedance using Z = √(R² + (X_L − X_C)²).
- Use I = V/Z and the phase angle to interpret whether the circuit is inductive or capacitive.
Frequently Asked Questions
Q: What does a circuit simulator calculator do?
It calculates circuit quantities such as equivalent resistance, current, voltage drops, power, RC time constants, impedance, phase, and resonance while showing a visual diagram.
Q: What is the difference between series and parallel circuits?
In a series circuit, components share the same current. In a parallel circuit, components share the same voltage but current splits across branches.
Q: What is an RC time constant?
The time constant τ = RC describes how quickly a capacitor charges or discharges. After about one time constant, the capacitor has completed roughly 63% of the change.
Q: What is impedance in an AC circuit?
Impedance is the AC version of resistance. It combines resistance and reactance, so it affects both current size and phase shift.
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