Here, in this article, we are going to see a single-phase Transformer Connection Diagram. Here we have shown both Center Taped and Normal Type single phase transformers. Here, we have shown the 230V input transformers. But if your country(United States) uses other voltages such as 120V, you must use a 120V input voltage transformer. That means, here we have used a 230V/12V transformer here, but you can also use a 230V/12V or 120V/12V transformer as per the voltage available in your country.

A transformer is an electrical machine that helps to step up or step down the voltage level without changing power and frequency.

The normal step-down transformer has two input terminals and two output terminals that are connected to the two ends of the primary winding and secondary winding respectively.

But the center-tapped transformer has two input terminals and three output terminals. The two input terminals are brought from the two ends of the primary winding whereas the three output terminals are brought from the two ends of the secondary winding as well as from the center of the coil by making a tapping. So the total voltage across the secondary winding is divided equally in each part. So, you will get the full voltage across the terminals brought from the ends of the coil. And you will get half of the full voltage across the center-tapped terminal and any one-end terminal.

Here, we have shown 230V/12V transformers but this connection is suitable for all other 24V, 34V, or 48V transformers.

As we know the transformer works with an AC supply, so there is no need to make proper polarity of the connection. The input terminal of the transformer should be connected to the single-phase supply. The normal transformer has two terminals so here in this case you will gate 12V AC supply. But if you use another output-rated transformer you will get the rated voltage.

The main confusion is in the center-tapped transformer. For example, here we have used a 230V/12V center-tapped transformer which means here you will get two different voltages. You will get 12V across the center tapped terminal and any one side terminal and you will get 24V across the two ends terminals.

Both end side terminals will have the same color(here blue) and the center-tapped will have a different color(here black). So, you can easily identify the end-side terminals and center terminals.

So, the conclusion is that a 12V center-tapped transformer will give you 12V and 24V voltage. Similarly, a 24V center-tapped transformer will give you 24V and 48V voltage. And the 36V transformer will give you 36V and 72V voltage.

Of course, the center-tapped transformer with the same rating will be costlier than a normal transformer. Also, remember that there are some special types of transformers available in the market that have multiple tapping. That means they provide different output voltage levels. So, before connecting you must read their user manual or identification given on the transformer.