Shop Windows to the Universe

Arches National Park Geology Tour provides an extensive, visually rich description of the geology of Arches, by Deborah Ragland, Ph.D. See our DVD collection.
Transformers are often used in electrical circuits to change the voltage of electricity flowing through a circuit.
Click on image for full size
Image courtesy of Wikipedia (modified by Windows to the Universe staff).

The Role of Voltage Transformers in Our Electric Power Systems

Transformers are devices used in electrical circuits to change the voltage of electricity flowing in the circuit. Transformers can be used either to increase the voltage (called "stepping up") or decrease the voltage ("step down").

When electrical energy travels long distances in wires, some of the energy is lost. This happens to electricity during the journey from a power plant to your home. Less energy is lost if the voltage is very high, so electrical utilities use high voltage in long-distance transmission wires. However, this high voltage is too dangerous for home use. Electrical utilities use transformers to change the voltage of electricity as it travels from the power plant to you. First, the voltage of electricity coming from the power plant is "stepped up" using transformers to the right level for long-distance transmission. Later, the voltage is stepped down before it enters your home - once again using transformers.

In order for the electrical power distribution network to function, voltages must be stepped up before power is transmitted great distances over power lines. One major problem is that power is lost between the power plant and the consumers because currents use some of the power to heat the transmission lines. The power transmitted along the line is equal to the voltage times the current. The higher the voltage the lower the current that must flow within the transmission lines to deliver the same power. Lower currents produce much less heating and much less power loss. Of course, the high voltages (needed to drive the low currents) must be stepped back down before power is supplied to our homes. Transformers are the critical elements that step up and down the voltages at each end of the line.

Last modified February 25, 2009 by Randy Russell.

Shop Windows to the Universe Science Store!

Our online store includes books on science education, ranging from evolution, classroom research, and the need for science and math literacy!

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Problems Restoring Electrical Power After a Blackout

Sometimes a whole electric power system shuts down. This can happen after a strong space weather storm. It is hard to get the whole system running again after it has been shut down all the way. The main...more

How Space Weather Can Damage Transformers

Our electrical power system supplies our homes and businesses with electricity. Space weather storms can mess up the power system, leaving us without electricity. A transformer is a piece of equipment...more

Space Weather Effects on Electrical Power Systems

Space weather "storms" can cause problems on Earth. They can even mess up our systems that make electricity and that deliver electricity to peoples' houses. Sometimes really big space weather storms can...more

Direct Current (DC) & Alternating Current (AC) Electricity

There are two types of electrical currents that can flow through wires: direct current (DC) and alternating current (AC). Direct current (DC) flows in the same direction all the time through an electric...more

Radiation Can Damage Electronics

Radiation can damage electronic circuits. Radiation can also cause electronics to malfunction. Radiation can damage the materials used in electronics over time. That can make the electronics wear out sooner....more

The Magnetic Field

The force of magnetism causes material to point along the direction the magnetic force points. As shown in the diagram to the left, the force of magnetism is illustrated by lines, which represent the force....more

Planetary Magnets

The Earth is a good example of a planetary dipole, where the lines of force point in a direction out of the South (magnetic) Pole and into the North (magnetic) Pole. Planets can also show evidence of quadrupoles...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF