Information About Voltage Transformers

Voltage transformer can have different meanings in the popular imagination. Generally, and more accurately, it refers to any device that either raises or lowers the voltage of an electric current. These devices, which should simply be called "transformers," are present everywhere in modern society, from the giant transforming stations located near power plants to the AC adapters used in everyday devices. They are also present in the voltage adapters used by travelers, and these are also sometimes called "voltage transformers."

  • 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 in America often appear as large cylinders perched atop a telephone pole, with three or four feed cables running into nearby houses. All voltage converters used by travelers are transformers.


  • 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 will result in changes in the magnetic field, which in turn will alter the voltage of the secondary coil/circuit.


  • As a travel device, voltage transformers allow North Americans to use some of their electronics and appliances while abroad. 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 that are taken abroad need further transformation to be safely used. There are three common uses for transformers besides their use as a travel device. 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. Finally, transformers are found in every AC adapter.


  • Voltage transformers that are used in travel have a consideration beyond just the voltage itself: namely wattage. All of these small, portable travel devices provide electricity at a set level of watts. A 50-watt converter is good for most basic electronics, such as recharging batteries or an iPod, but they cannot run a computer that requires 90 or 100 watts of power. Few, if any, voltage converters can power an electricity-gobbling hair dryer or space heater.

Expert Insight

  • One of the amazing things about transformers is that they are perhaps the most energy-efficient machines ever designed by man. 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.

20th Jan 2015

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