Transformer Turns Ratio Calculator
Calculate transformer turns ratio, secondary voltage, and current from primary and secondary winding parameters.
Turns Ratio (Np:Ns)
4.00
Turns Ratio (Np:Ns) vs Primary Voltage
公式
## Transformer Turns Ratio The turns ratio determines the voltage transformation between primary and secondary windings. ### Formulas **Turns Ratio = Vp / Vs = Np / Ns** **Ip = VA / Vp** and **Is = VA / Vs** Current transforms inversely: higher voltage means lower current, preserving power (minus losses). **Power Loss = VA x (1 - Efficiency)** Typical transformer efficiencies range from 90% (small) to 99% (large utility).
计算示例
480 V to 120 V step-down, 5 kVA, 95% efficient.
- 01Turns ratio: 480 / 120 = 4.00:1
- 02Primary current: 5000 / 480 = 10.42 A
- 03Secondary current: 5000 / 120 = 41.67 A
- 04Power loss: 5000 x 0.05 = 250 W
- 05Output power: 5000 x 0.95 = 4,750 W
常见问题
Can a transformer change frequency?
No. A standard transformer passes the same frequency through. To change frequency, use a frequency converter.
What determines transformer efficiency?
Core losses (hysteresis and eddy currents) and copper losses (I^2R in windings). Larger transformers are generally more efficient.
What is VA rating vs watt rating?
VA is apparent power. For purely resistive loads, VA equals watts. For reactive loads, watts = VA x power factor.
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