Transformer winding – wind your own transformer at home using some simple mathematics, and also known which size of copper I want to use when winding the Transformer. Do you want to what is transformer?
Transformer Windings and Working

The transformer is defined as an electrical device that works in the principle of the electromagnetic induction of coils. The transformer contains copper wire and metallic sheets. There are different type of transformers are available in the market. Mainly that transformers are using to convert the high voltage into low volt or convert the low voltage into high volt.
That’s commonly known as step-up transformer and step down transformer. Step up transformer does the job of converting the low voltage into a high voltage level. And the step-down transformer that does the job of converting the high voltage into low voltage.
The transformer contains the primary and the secondary coil winding. In step down transformer, the primary coil contains less number of turns and the secondary coil have least more of turns than the primary. In a step-up transformer, the primary coil is thick copper wire with less number of turns. And the secondary coil having more numbers of turns.
Types of Transformer
There are different type of transformer are using. The commonly using transformers are
- Step up transformers
- Step down transformers
- Air core transformers
- Iron core transformers
- Toroidal transformers
In this article, I am going to simply say about how to calculate the transformer winding and which size of the copper wire we need to choose while winding the transformer.
Transformer winding coil turns calculation
The winding of the transformer is based on the equation of
NS/NP = VS/VP
- NS = Number of turns in secondary coil
- NP = number of turns in primary coil.
- VS = voltage in secondary coil.
- VP = voltage in primary coil.
For the demonstration on purpose, I am going to construct a 12-volt transformer that working in a 230 volt. Now we need to calculate the number of turns in the primary and secondary coil of the best Transformer.
I am not mentioning the core size it will be changing according to the power of the transformer. This equation is only for calculating the number of turns during the transformer winding.
Example Calculation
VS = 230 volt. VP = 12 volt.
NS = ? NP = 80 turns.
How we want to calculate the secondary turns of this transformer.
NS/ Np = VS/ VP
NS = ( VS*NP) / VP
= ( 230/1500) *12
=1533.33 turns
That is 1540 turns needed for producing 12 volt on primary coil.
Copper wire gauge and Ampere
You are confused when winding a transformer, is which gauge of the copper wire I used for the winding transformer. And
how many amperes can we get? Or you are decided to make a 5 a transformer and you don’t know which copper I use? Here is the solution for theses confusion. Choose the copper size according to the specific ampere you need.
Copper Gauge amp Rating
| Gauge number (awg) | Ampere |
| 7 | 44.2 amp |
| 8 | 33.3 amp |
| 9 | 26.5 amp |
| 10 | 21.2 amp |
| 11 | 16.6 amp |
| 12 | 13.5 amp |
| 13 | 10.5 amp |
| 14 | 8.3 amp |
| 15 | 6.6 amp |
| 16 | 5.2amp |
| 17 | 4.1 amp |
| 18 | 3.2amp |
| 19 | 2.6 amp |
| 20 | 2.0 amp |
| 21 | 1.6 amp |
| 22 | 1.2 amp |
| 23 | 1.0 amp |
| 24 | 0.8 amp |
| 25 | 0.6 amp |
| 26 | 0.5 amp |
| 27 | 0.4 amp |
| 28 | 0.3 amp |
| 29 | 0.29 amp |
| 30 | 0.22amp |
To make 5 amp transformer use 16 gauge copper wire on the transformer when winding.




