Ideal Transformer Calculator

Calculate voltage, current, and power relationships in ideal transformers using turns ratio

Calculate Transformer Parameters

Number of turns in the primary coil

Number of turns in the secondary coil

V

Voltage across the primary coil

V

Voltage across the secondary coil

A

Current through the primary coil

A

Current through the secondary coil

Transformer Results

Basic Parameters

Turns Ratio (Ns:Np):N/A
Transformer Type:N/A
Efficiency (ideal):100%

Calculated Values

Key Formulas:

• Voltage: Vs = Vp × (Ns/Np)

• Current: Is = Ip × (Np/Ns)

• Power: Pp = Ps (ideal transformer)

Transformer Analysis

Example Calculation

Step-down Transformer (Power Supply)

Application: Converting 240V AC to 12V AC for electronics

Primary windings: 1000 turns

Secondary windings: 50 turns

Primary voltage: 240V AC

Primary current: 0.5A

Calculation

Turns ratio = Ns/Np = 50/1000 = 0.05

Secondary voltage = 240V × 0.05 = 12V

Secondary current = 0.5A ÷ 0.05 = 10A

Result: 12V AC at 10A capacity

Transformer Types

Step-up

Ns > Np, increases voltage

Used in power transmission

Step-down

Ns < Np, decreases voltage

Used in power supplies

=

Isolation

Ns = Np, same voltage

Provides electrical isolation

Key Principles

Voltage is proportional to turns ratio

Current is inversely proportional to turns ratio

Power is conserved (ideal transformer)

Works only with AC (alternating current)

Based on electromagnetic induction

Understanding Ideal Transformers

How Transformers Work

A transformer consists of two coils (primary and secondary) wound around a common magnetic core. When AC current flows through the primary coil, it creates a changing magnetic field that induces voltage in the secondary coil through electromagnetic induction.

Key Assumptions

  • No energy losses (100% efficiency)
  • Perfect magnetic coupling between coils
  • No magnetic flux leakage
  • Infinite magnetic permeability of core

Mathematical Relationships

Voltage Transformation

Vs/Vp = Ns/Np

Secondary voltage equals primary voltage times the turns ratio

Current Transformation

Is/Ip = Np/Ns

Current transformation is inverse of voltage transformation

Power Conservation

Pp = Ps = Vp × Ip = Vs × Is

Input power equals output power in ideal transformers

Real vs. Ideal Transformers

Ideal Transformer:
  • • 100% efficiency
  • • No losses
  • • Perfect magnetic coupling
Real Transformer:
  • • 95-99% efficiency
  • • Copper and iron losses
  • • Magnetic flux leakage

Transformer Applications

Power Distribution

Step-up transformers at power plants increase voltage for efficient long-distance transmission, while step-down transformers reduce voltage for safe residential use.

Example: 240kV → 120V

Electronic Devices

Power adapters and chargers use step-down transformers to convert household voltage to safe levels for electronic devices.

Example: 120V → 12V

Isolation

Isolation transformers provide electrical safety by eliminating direct electrical connection between input and output.

Example: 1:1 ratio