A transformer is an electrical device which, by the principles of electromagnetic induction, transfers electrical energy from one electric circuit to another, without changing the frequency. The energy transfer usually takes place with a change of voltage and current. Transformers either increases or decreases AC voltage.
Transformers are used to meet a wide variety of needs. Some transformers can be several stories high, like the type found at a generating station or small enough to hold in your hand, which might be used with the charging cradle for a video camera. No matter what the shape or size, a transformers purpose remains the same: transforming electrical power from one type to another.
There are many different types of transformers in use today. This resource will take a closer look at Power Transformers, Auto Transformers, Distribution Transformers, Instrument Transformers, Isolation Transformers, Potential Transformers and Current Transformers.
How Transformers Work?
Basic Transformer DesignIt is important to remember that transformers do not generate electrical power; they transfer electrical power from one AC circuit to another using magnetic coupling. The core of the transformer is used to provide a controlled path for the magnetic flux generated in the transformer by the current flowing through the windings, which are also known as coils.
There are four primary parts to the basic transformer. The parts include the Input Connection, the Output Connection, the Windings or Coils and the Core.
Input Connections – The input side of a transformer is called the primary side because the main electrical power to be changed is connected at this point.
Output Connections – The output side or secondary side of the transformer is where the electrical power is sent to the load. Depending on the requirement of the load, the incoming electric power is either increased or decreased.
Winding – Transformers have two windings, being the primary winding and the secondary winding. The primary winding is the coil that draws power from the source. The secondary winding is the coil that delivers the energy at the transformed or changed voltage to the load. Usually, these two coils are subdivided into several coils in order to reduce the creation of flux.
Core – The transformer core is used to provide a controlled path for the magnetic flux generated in the transformer. The core is generally not a solid bar of steel, rather a construction of many thin laminated steel sheets or layers. This construction is used to help eliminate and reduce heating.
Transformers generally have one of two types of cores: Core Type and Shell Type. These two types are distinguished from each other by the manner in which the primary and secondary coils are place around the steel core.
Core type – With this type, the windings surround the laminated core.
Shell type – With this type, the windings are surrounded by the laminated core.