Transformer — Step-Up & Step-Down

The Transformer Simulator demonstrates how electrical transformers transfer energy between primary and secondary windings through electromagnetic induction. You can explore step-up and step-down voltage transformation, the turns ratio (N₂/N₁), primary and secondary currents, and the impact of copper and iron losses on efficiency. The canvas displays an animated transformer with magnetic flux flowing through the core and synchronised AC waveforms for both windings.

This tool is designed for electrical engineering students, power systems trainees, and physics learners studying Faraday’s law of electromagnetic induction, voltage transformation ratios, and real-world transformer losses.

The simulator opens in Simulate mode with V₁ = 120 V, N₁ = 100 turns, N₂ = 200 turns, and R_L = 500 Ω (ideal transformer, no losses). This gives a turns ratio of 2.0 and a step-up output of 240 V. To begin:

• Drag the V₁ Primary slider (1–240 V) to change the input voltage.
• Adjust N₁ and N₂ sliders (10–500 turns) to set the turns ratio. If N₂ > N₁, the transformer steps up; if N₂ < N₁, it steps down.
• Change the Load Resistance R_L (10–10,000 Ω) to vary the secondary current and power output.
• Enable the Real Transformer (losses) checkbox to add copper (I²R) and iron (hysteresis + eddy current) losses, and observe efficiency drop below 100%.

Navigate through Simulate, Explore, Practice, and Quiz modes using the pill tabs at the top.

Simulate mode provides the interactive transformer workspace. The canvas shows the transformer schematic with animated magnetic flux lines and AC waveforms. Key controls:

• V₁ Primary slider: Sets the input AC voltage from 1 to 240 V.
• N₁ and N₂ sliders: Set primary and secondary turns. The turns ratio a = N₂/N₁ directly determines the voltage transformation: V₂ = a × V₁.
• R_L Load slider: Sets load resistance. Secondary current I₂ = V₂/R_L, and primary current I₁ = a × I₂ (ideal).
• Real Transformer checkbox: Activates copper losses (proportional to I²) and iron core losses (fixed losses due to hysteresis and eddy currents). Efficiency becomes η = P_out/P_in × 100%.

The readout cards display: turns ratio, transformer type (step-up or step-down), secondary voltage V₂, primary current I₁, secondary current I₂, input power P_in, output power P_out, and efficiency percentage.

Explore mode organises transformer theory into three categories:

• Transformer Basics: Covers electromagnetic induction, Faraday’s law, turns ratio, ideal transformer equations (V₂/V₁ = N₂/N₁), and the principle that power is conserved in an ideal transformer.
• Losses & Efficiency: Explains copper losses (I²R heating in windings), iron losses (hysteresis loss from magnetic domain reversal and eddy current loss from circulating currents in the core), and how laminated silicon steel cores minimise eddy currents.
• Applications: Describes power transmission (step-up for long-distance, step-down for distribution), isolation transformers, instrument transformers (CTs and PTs), and autotransformers.

Each concept card provides formulas, explanations, and an interactive canvas illustration.

Practice mode generates problems such as: “A transformer has N₁ = 200 turns and N₂ = 50 turns. If V₁ = 240 V, find V₂”, “Calculate primary current if secondary current is 2 A and turns ratio is 5:1”, or “Find efficiency if P_in = 500 W and total losses are 25 W.” Enter your answer and receive a step-by-step solution.

Quiz mode presents 5 multiple-choice questions covering turns ratio, step-up vs step-down identification, current transformation, copper and iron losses, and efficiency calculations. Review your score and detailed explanations at the end.

• Start with an ideal transformer (losses unchecked) to understand the basic turns ratio relationship, then enable losses to see real-world behaviour.
• Set N₁ = N₂ to create a 1:1 isolation transformer — voltage stays the same but the circuits are galvanically isolated.
• Notice that when you step up voltage, current steps down proportionally — power is conserved (P = V × I).
• With the Real Transformer mode on, try increasing load current by lowering R_L. Watch copper losses (I²R) increase significantly while iron losses remain roughly constant.
• For maximum efficiency, transformers operate best at or near rated load. Very light loads give poor efficiency because iron losses dominate.
• Remember: turns ratio a = N₂/N₁. If a > 1, it steps up voltage; if a < 1, it steps down voltage.
• Use Practice mode to drill the three core equations: V₂ = a×V₁, I₂ = I₁/a, and η = P_out/P_in × 100%.