Toroidal transformers are the smallest-sized transformers in regards to both weight and volume, which works to the advantage of toroidal transformer manufacturers because they can be easily incorporated into any power source application that can accommodate its shape. Industries that benefit from toroid transformers include electronics, aerospace, musical instrument, private security, meteorology and transportation and many more. 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.

Spark Industries
Phoenix, AZ | 602-281-2046Since 1975, we have been leading the way in manufacturing high-voltage, low-power sources. And over the years, we've grown to extend our capabilities by producing specialty transformers, audio coils, inductors, magnetics, printed circuit boards and other electrical components. High quality, competitive price.

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.

Sun Transformer
McLeansboro, IL | 618-643-2555ISO 9001:2000 registered Sun Transformer creates custom transformers optimized for the needs of many industries. Large power, isolation & auto transformers, printed circuit mount power transformers, units for hostile conditions, units with ferrite or nickel cores for digital telecommunications use, etc.

Wabash Transformer
Addison, IL | 630-628-9999Wabash Transformer Inc. was founded in 1966, and is presently located in Addison, Illinois. This facility offers a full range of Custom and Standard power transformers. Wabash Transformer applications include HVAC, Medical, Pool and Spa, Metering equipment, Household appliances and many others.

Used as transformers in main power supplies, additional applications for toroid power transformers include audio amplifiers, battery chargers, induction loop equipment, household appliances, motor drives, cranes, lighting and medical devices. Toroidal transformers are also used as inductors in low frequency transmitters and receivers.
The central part of a toroidal transformer is its donut-shaped core. The core is constructed from grain-oriented silicon-iron or permalloy, which is slit to form a steel strip. The steel strip is then wound into a coil, made from powdered iron. The construction of the strip ensures that all of the molecules are aligned with the direction of flux, or the rate of flow of energy across a given surface, and increases the capacity for magnetic induction.
Since the core is closed and ring-shaped, air gaps are eliminated that are inherent in other cores. The cross-section of the core is typically either square or rectangular but can also be cylindrical in pricier cores.
The primary and secondary coils are wound in a densely concentrated manner to ensure that the entirety of the core's surface is covered. The two coils are linked by a magnetic field and act as conductors. When the primary coil receives AC voltage, this produces a varying magnetic field of voltage surrounding the conductor; the magnetic field activates the secondary conductor coil. This results in the toroid transformers changing the voltage and transferring electrical energy, ideally with the least amount of energy loss.
The design of toroid transformers prevents energy loss by confining the magnetic flux in the core. There are two directions of fluxes in the toroid magnetic field. Poloidal flux threads the hole in the center of the torus, and toroidal flux is parallel to the core of the torus.