Step down power transformers are extremely popular with American expatriates who continue using American appliances, such as microwaves or vacuums, after moving to Europe or other foreign countries. However, step down transformers are most widely used in power transmission applications at power-generating stations to raise voltages with a corresponding decrease in current. Read More…

Leading Manufacturers
Johnson Electric Coil Company
Antigo, WI | 800-826-9741We believe in offering the very best to all customers. We offer a full range of transformers, including electric transformers, current, and toroidal transformers.

Amgis Toroidal Power Products
Houston, TX | 832-400-4985AMGIS can supply your company with a variety of toroidal power products. Whether the application requires power toroidal transformers, toroidal inductors, commercial or medical isolation transformers, 3 phase transformers, auto transformers, high efficiency transformers for renewable energy, or custom toroidal applications, Amgis has a solution for your needs.

Lenco Electronics, Inc.
McHenry, IL | 815-344-2900Lenco Electronics, Inc. specializes in a wide variety of custom electric transformers. Lenco’s success has not come about by accident, but by providing its customers with high-quality products.

Magnetic Specialties, Inc
Telford, PA | 267-384-5231For half a century, Magnetic Specialties has created specialized electrical control components, subassemblies and devices for original equipment manufacturers of industrial equipment. Our business components include electric transformers, high accuracy instrument transformers, specialty transformers, toroids, inductors, filter, magnetic amplifiers and more. To learn more give us a call today.

Prem Magnetics Inc.
Johnsburg, IL | 815-385-2700Prem Magnetics was organized in 1972 as the Magnetics Division of Prem Enterprises (a machine shop) to be a manufacturer of coils and transformers. Prem Magnetics remains a leader in the transformer industry. In addition to our Illinois production facility, Prem operates a facility in Tecate, Mexico to manufacture products to the same quality standards. We are located roughly 40 miles northwest of Chicago, allowing access to anywhere in the world via numerous shipping hubs.

Very high voltages and low currents are used for long-distance transmission lines in order to reduce power losses; as a result, at the receiving end step-down transformers reduce the voltage and increase the current to the lower residential or industrial voltage levels. Materials used to construct the coil windings include copper, special steel alloys, chromium, nickel and aluminum, of which copper windings are the most efficient as well as being a little more costly.
Sizes of step down transformers range from large devices intended for use in electrical power systems, such as power plants, to much smaller units that are used in electronic equipment such as loudspeakers in radios, high fidelity equipment and television sets.
A step down transformer is comprised of two sets of coils or windings linked by a magnetic field. The core can be a ferrite compound or a laminated core wound with bare copper or enameled coils. The coils are primary and secondary and function as conductors. Although there is no connection between the two circuits, the coil windings are inductively linked.
The principal function of a step down transformer is to convert high voltage, low current power into low voltage, high current power. The conversion begins when the primary coil receives alternating current, or AC, voltage; this produces a varying magnetic field of voltage surrounding the conductor, and the magnetic field activates the secondary conductor coil. Once the voltage conversion is made, the energy is transferred to the load center and the electrical process continues from there.
The ratio of turns (also known as windings) in the primary coil to the number of turns in the secondary coil determines the magnitude of the voltage; in a step down transformer there will be fewer turns in its secondary coil than the primary. Even though there are fewer turns, the turns in the secondary coil are of a larger gauge wire than used in the primary coil in order to handle the increased current power that has been transferred to the secondary coil.
The voltage ratio between the windings of the primary and the secondary circuit mirrors the ratio of the number of windings. Correctly used, step down transformers can protect against safety hazards such as short-circuiting, blowing equipment or starting fires.