Why Use Transformers?

The transformer is one of the key inventions fundamental to creating the electrified world. The AC electric model, with its high voltage power transmission, is completely dependent on transformer technology. As AC is the dominant electric model around the world, modern civilization would be impossible without the transformer.

Identification

A transformer is a device for changing the voltage of electricity. In popular use, it refers to the type of transformer that steps high voltage electricity down to the level necessary for domestic use. If you have electrical feed wires on telephone poles in your neighborhood, look around. Transformers often appear as large cylinders perched atop a pole, with three or four feed cables running into nearby houses. Voltage converters used by travelers are also transformers.

Function

A transformer changes voltage by means of mutual electromagnetic induction. The electrical current running through the primary coil/circuit is used to create a magnetic field. Changes in the current result in changes in the magnetic field, which in turn alters the voltage of the secondary coil or circuit. The result is that by making changes in the primary coil, the voltage of the current in the secondary coil can be either stepped up or stepped down.

Types

There are four common uses for transformers. Two are to step up voltage for high voltage power transmission, and then step it down for distribution and consumption. This is done between power plants and consumers, making possible the transmission of electricity over long distances. Without the transformers used in this application, our alternating current (AC) method of power distribution would be impossible, and instead we would use direct current (DC) power distribution. DC power would mean having a small power plant in virtually every neighborhood area, due to the substantial limits involved in transmitting all electricity at the same voltage at which it will be consumed.
The third use for transformers is in travel converters. North American electricity is distributed for consumption at 110 volts, while internationally it is more common to see it used at 220 volts. Thus, American computers and other appliances used abroad need adapters to be safely used. AC adapters are used in many devices and appliances in daily use.

History

The science behind transformers was demonstrated in principle by Michael Faraday in 1831. Transformers for commercial application came into their own between the mid-1880s and the early 1890s. The technology was a result of a combination of independent efforts by Mikhail Dolivo-Dobrovolsky, William Stanely and Nikola Tesla.

Expert Insight

Transformers are perhaps the most energy efficient machines ever designed. Most designs suffer very little power loss in changing voltages. The least efficient designs are actually those found in the common power adapters, such as the one attached to laptop computers. However, even these transformers are more than twice as energy efficient as an internal combustion engine, for example.