# Multi Winding Transformer

The Multi Winding Transformer can have two or more primary or secondary windings that allow different combinations of voltage and current.

Multiple Winding Transformers usually have a single primary winding with two or more secondary windings.But the beauty of transformers is that they allow us to have multiple windings on the primary or secondary side.Transformers with multiple windings are commonly known as Multi Winding Transformers.

The principle of operation of a Multi Winding Transformer is no different from that of an ordinary transformer.Primary and secondary voltages, currents and rotational ratios are all calculated the same, this time the difference is that we need to pay special attention to the voltage polarity of each coil winding, the dot rule marks the positive (or negative) polarity of the winding.

Multi-winded transformers, also known as multi-winded, contain multiple primary or multiple secondary windings on a common laminated core, hence their names.They can be a single-phase transformer or a three-phase transformer (multi-winded, multi-phase transformer) the working logic is the same.

Multiple Winding Transformerscan also be used to provide an upgrade, a drop or a combination of both between various windings.In fact, a multi-winded transformer can have several secondary windings on the same core, each of which provides a different voltage or current level output.

Since transformers operate on the principle of mutual induction, each winding of a multi-winding transformer supports the same number of volts per turn, so the volt-amp product in each winding is the same, that is, any rotational ratio between NP /N S = VP /VS and individual coil windings is relative to the primary source.

In electronic circuits, a transformer is often used to provide various low voltage levels for different components in the electronic circuit.A typical application of multi-winding transformers are power supplies and triage switching converters.Therefore, a transformer can have several different secondary windings, each electrically isolated from others, just as it is electrically isolated from the primary.Then each of the secondary coils will produce a voltage proportional to, for example, the number of coil rotations.

Above is an example of a typical "multi-winding transformer" with a series of different secondary windings that feed various voltage levels.Primary windings can be connected separately or interconnected to operate the transformer at higher feeding voltages.

Secondary windings can be connected in various configurations that produce a higher voltage or current source.It should be noted that it is only possible to connect in parallel transformer windings if the two windings are electrically identical.In other words, the current and voltage values are the same.

## Double Voltage Transformers

There are a series or multiple winding transformers with two primary windings with the same voltage and current values and two secondary windings with the same voltage and current ratings.These transformers are designed to be used in a variety of applications with windings connected in series or parallel combinations for higher primary voltages or secondary currents.Such multi-winding transformers are more commonly called Double Voltage Transformers, as shown.

### Dual Primary and Double Secondary Transformer

There are two primary windings and two secondary windings in the transformer, a total of four.Connections to primary or secondary windings should be made correctly with double voltage transformer.If connected incorrectly, it is possible to create a short circuit that will usually destroy the transformer when energized.

We have previously said that double voltage transformers can be connected to operate from power sources of different voltage levels, so they are called "double voltage transformers".For example, suppose the primary winding may have a voltage rating of 240/120V in the primary and 12/24V in the secondary.To achieve this, each of its two primary windings, therefore, is rated 120V, and each secondary winding is rated 12V.The transformer must be connected so that each primary winding gets the appropriate voltage.Consider the circuit below.

### Series Connected Secondary Transformer

Here in this example, since the two windings are the same, half of the feed voltage, that is, 120V, falls into each winding and the same primary current passes through both, so the two 120V grade primary windings are serially connected together throughout a 240V feed.Each of the two secondary windings, rated 12V, 2.5A, is connected serially by secondary terminal voltage, the sum of two separate winding voltages that give 24 Volts.

Since the two windings are connected serially, the same amount of current passes through each winding, after which the secondary current is the same at 2.5 Amps.Therefore, for a series of connected secondary, the output in our example above is rated 24 Volts, 2.5 Amps.Consider the following parallel connected transformer.

### Parallel Connected Secondary Transformer

Here we kept the two primary windings the same, but the two secondary windings are now connected in a parallel combination according to their point orientation.As before, each of the two secondary windings is rated 12V, 2.5A, so the secondary terminal voltage will be the same at 12 Volts, but the current is added.Then for a parallel connected secondary, the output in our example above is rated 12 Volts, 5.0 Amps.

Of course, different binary voltage transformers will produce different amounts of secondary voltage and current, but the principle is the same.Secondary windings must be connected correctly to produce the required voltage or current output.

Point orientation is used in windings to specify terminals with the same phase relation.For example, connecting two secondary windings in opposite point orientation causes two magnetic axles to cancel each other out, resulting in zero output or damage to the transformer.

Another type of dual voltage transformer with only one secondary winding with "gear" at the electrical center point is called the Center Stage Transformer.

## Central Stage Transformers

A center stage transformer is designed to provide two separate secondary voltages, V A and V B with a common connection.This type of transformer configuration produces a two-phase, 3-wire feed.

Secondary voltages are the same and the supply voltage is proportional to V P , so the power in each winding is the same.The voltages produced throughout each secondary winding are determined by the rotation rate as shown.

### Touch-in-the-Middle Transformer

Above is a typical mid-stage transformer.The stage point is in the very center of the secondary winding, which provides a common connection for two equal but opposite secondary voltages.When the middle stage is grounded, the V A output will be positive in nature relative to the soil, while the voltage in the other secondary V B will be negative and opposite in nature, that is, 180 is that electrical degree. phased with each other.

However, there is a disadvantage to using an unpluthed central stage transformer, and this is that it can produce unbalanced voltages in two secondary windings due to non-symmetrical currents flowing in the common third connection due to unstable loads.

We can also produce a center stage transformer using double voltage transformer from above.By connecting secondary windings in series, we can use the central connection as a faucet as shown.If the output from each secondary is V, the total output voltage of the secondary winding will be equal to 2V as shown.

### Middle Plug Transformer Using Double Voltage Transformer

Multi Winding Transformers have many applications in electrical and electronic circuits.They can be used to provide different secondary voltages to different loads.Connect the windings together in series or parallel combinations to provide higher voltages or currents, or serially connect the secondary windings to produce a center-stage transformer.

In the next tutorial on transformers , we will look at how autotransformers work and see that they have only one main primary winding and do not have a separate secondary winding.