Transformers

Transformers – versatile help in adjusting the voltage to the needs

By creating various electronic and robotic projects, such as an automatic lighting control system at home, we will have to deal with the way our prototype is powered. In such a situation, we will have to learn more about how they work and what transformers are. In most situations, the transformer will allow the entire project to run. Why it is so?

The principle of a transformer is to transfer AC electricity by induction from one electrical circuit to another, maintaining the original frequency while changing the electrical voltage. What is changed is the voltage: from higher to lower, from lower to high.

Transformers consist of two basic elements - a steel core and windings (primary and secondary windings) made of copper or aluminum. The most commonly used type of winding is a cylindrical winding. In this scheme, the primary and secondary windings take the form of concentric cylinders. Nevertheless, there are many other types of windings. The type of bonding also defines the type of the transformer. Hence, we distinguish, for example, colloidal transformers.

Transformer – to change the electrical voltage

Transformers are designed to change the electrical voltage. The key to understanding how transformers work is their specific design. As we said above, an integral element of any transformer is the winding (and they can be made of various materials and have various shapes). The key point is that one of the windings is connected to an alternating current, which creates an alternating magnetic field. The flux conducted by the core of this magnetic field flows through the remaining coils in the transformer. The change in the magnetic flux in the coils causes electromagnetic induction. In other words, this is how an electromotive force is created in the transformer's coils - it is just electrical voltage. If a transformer has fewer secondary than primary windings, it induces a lower voltage, and this type of transformer is called step-down.

The first transformers were built at the end of the 19th century. However, the most important discovery enabling their future production was made much earlier – it was Faraday's law of induction (1831).

Types of transformers

Over the years, many different transformers have been manufactured depending on the type of application. The basic criterion that distinguishes these devices is phase. In multi-phase systems, multi-phase (three-phase) transformers are used. Another type of device are plane transformers. For low voltage, the transformers are air-insulated. In turn, special transformer oils are an insulator in high voltage transformers, which also cool the entire machine.

The autotransformer is also worth mentioning. In such devices, one winding is part of the other. This equipment is characterized by a greater number of windings and winding leads. In addition to the above, there are also many other types of transformers, including: power transformers, toroidal transformers, special transformers for measuring systems, variable voltage transformers with taps and safety transformers.