1. What is the Winding Resistance Formula?

The winding resistance formula \( R = \rho \times \frac{L}{A} \) calculates the electrical resistance of a transformer winding based on the material's resistivity, length of the conductor, and its cross-sectional area.

2. How Does the Calculator Work?

The calculator uses the winding resistance equation:

Where:

• \( R \) — Winding resistance (ohms)
• \( \rho \) — Resistivity of the material (ohm-m)
• \( L \) — Length of the conductor (meters)
• \( A \) — Cross-sectional area of the conductor (m²)

Explanation: The resistance increases with higher resistivity and longer conductor length, but decreases with larger cross-sectional area.

3. Importance of Winding Resistance Calculation

Details: Accurate winding resistance calculation is crucial for transformer design, efficiency analysis, heat dissipation estimation, and loss calculations.

4. Using the Calculator

Tips: Enter resistivity in ohm-meters, length in meters, and cross-sectional area in square meters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical resistivity values for winding materials?
A: Copper at 20°C has ρ ≈ 1.68×10⁻⁸ ohm-m, while aluminum has ρ ≈ 2.65×10⁻⁸ ohm-m.

Q2: How does temperature affect winding resistance?
A: Resistance increases with temperature. For copper, resistance increases about 0.393% per °C rise.

Q3: Why is winding resistance important in transformers?
A: It affects efficiency (I²R losses), voltage regulation, and temperature rise in the transformer.

Q4: How is cross-sectional area typically measured?
A: For round conductors, \( A = \pi r^2 \) where r is the radius. For rectangular conductors, \( A = width \times height \).

Q5: Can this formula be used for other conductors?
A: Yes, this fundamental formula applies to any uniform conductor, not just transformer windings.