A Comprehensive Guide to EI Core Transformer Construction

Power transformers are indispensable devices in modern days; any technical person is accustomed to these, but in the case of non-technical persons, also use these devices unconsciously. In this article, I will discuss the construction process of power transformers. If you would like to forge an electromagnetic induction (EI) core transformer, then the following formulas can be conducive for you. Let's halt the verbiage and initiate our calculations.

Area of Bobbin A: B×C

 

Turns per Volt N/V:

Where:

 N/V = turns per volt

 f = frequency (50/60 Hz)

 A = area of the bobbin in square meters

 Φ= maximum magnetic flux density (in Weber/m², varies in between 1-1.2 Wb/m²)

 

 Example Calculation Steps

Let's erect a design of a transformer with the following specifications:

Frequency, f = 50 Hz

Width of bobbin, B = 0.05 m (5 cm)

Length of bobbin, C = 0.07 m (7 cm)

Maximum flux density, = 1.2 Wb/m² (100 Wb/m²)

 

Step 1: Calculate the Area of Bobbin (A)

Step 2: Calculate Turns per Volt (N/V)

Using the turns per volt formula:

Step 3: Summary

Based on our example with a frequency of 50 Hz, a bobbin area calculated asand a maximum flux density of 1.2 Wb/m², we find approximately 1.08 turns/volt.

Step 4: Wire Size Selection

SWG, or Standard Wire Gauge, provides a measurement system for wire diameter, which is essential for selecting the appropriate gauge of wire when winding transformer coils. The thickness of the wire (measured in SWG) affects the resistance, current capacity, and heating characteristics of the transformer. Accurate wire sizing ensures efficient transformer operation, optimal performance, and reliability in applications. You can follow the chart to ensure precise wire size as required.

 

 

Final Note

The above findings are indicative, and computations can vary widely based on desired output levels, materials chosen, and operational parameters set by the engineers or designers. Always ensure to validate and iterate on designs using appropriate simulation tools and methodologies before physical implementation.