Transformer Turns Ratio & Saturation Calculator
Design efficient transformers by calculating primary/secondary turns and validating core saturation limits. Includes a database of magnetic core materials.
About
Transformer design involves balancing voltage requirements with the physical limitations of the magnetic core. The most critical failure point in custom transformer design is core saturation. If the number of primary turns is too low for a given frequency and core area, the magnetic flux density (B) exceeds the core's capacity, causing the inductor to behave like a short circuit, leading to catastrophic overheating.
This tool computes the ideal turns ratio for voltage transformation and, crucially, checks your design against the Bmax limits of common materials like Ferrite, Silicon Steel, and Iron Powder. It ensures your design remains in the linear region of magnetization, preventing efficiency losses and thermal runaway.
Formulas
The turns ratio (TR) is simply the ratio of voltages:
To avoid saturation, the minimum number of primary turns is derived from Faraday's Law:
Where Ae is in cm2 and Bmax is in Tesla.
Reference Data
| Material | Max Flux Density (Bmax) | Typical Freq Range | Permeability (μ) |
|---|---|---|---|
| Silicon Steel (Grain Oriented) | 1.5 - 1.7 T | 50/60 Hz | ~20,000 |
| Silicon Steel (Non-Oriented) | 1.2 - 1.4 T | 50/60 Hz | ~5,000 |
| Ferrite (MnZn) | 0.3 - 0.4 T | 10kHz - 1MHz | 1,000 - 10,000 |
| Ferrite (NiZn) | 0.3 T | 1MHz - 100MHz | 100 - 1,000 |
| Iron Powder | 1.0 - 1.4 T | 1kHz - 100kHz | 10 - 100 |
| Amorphous Metal | 1.5 T | Medium Freq | High |
| Nanocrystalline | 1.2 T | High Freq | Very High |
| Permalloy | 0.7 T | Sensitive Signal | ~100,000 |