What Is the Electrical Transformer Turns Ratio & Voltage Calculator?
An electrical transformer is a static electromagnetic device transferring electrical energy between circuits via mutual inductive coupling.
How Does the Electrical Transformer Turns Ratio & Voltage Calculator Work?
Alternating primary current creates fluctuating magnetic flux in a ferromagnetic core, inducing EMF in the secondary winding by Faraday’s Law.
Electrical Transformer Turns Ratio & Voltage Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
a = \frac{N_p}{N_s} = \frac{V_p}{V_s} = \frac{I_s}{I_p}, \quad Z_p = a^2 \cdot Z_s
Turns ratio a sets voltage transformation; secondary current scales inversely; impedance reflects as a squared.
How to Use the Electrical Transformer Turns Ratio & Voltage Calculator
- Specify primary and secondary turn counts.
- Enter primary AC supply voltage.
- Provide secondary load resistance in Ohms.
Step-by-Step Example Calculation
120V to 12V Step-Down Transformer
Input Values:
primaryTurns:480
secondaryTurns:48
primaryVoltage:120.0
secondaryLoadResistanceOhms:8.0
Worked Steps: With a 10:1 ratio, 120V steps down to 12.0V, driving 1.5A (18.0W) into an 8Ω load with reflected primary impedance Zp = 800Ω.
Understanding Your Result
Secondary Voltage (Vs): Transformed output voltage.
Secondary Current (Is): Current delivered to load.
Reflected Impedance (Zp): Apparent load seen by primary supply.
Factors That Affect the Result
- Turns ratio Np/Ns and core magnetic coupling coefficient.
When Should You Use This Calculator?
- Power distribution substation design, linear power supply sizing, and audio tube amplifier output impedance matching.
Assumptions & Limitations
- Assumes high-efficiency laminated iron core operating below magnetic saturation.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard AC transformer electromagnetic formulation.