Leading Toroidal Coil Manufacturers

A toroid coil is a coil of coated or insulated wiring wound on a circular-shaped structure made from powdered iron. It is commonly used as an inductor in electric connections and very low frequencies where very large inductances are necessary. Read More…

Toroidal Coils Toroidal coils are electrical components that consist of a doughnut-shaped metallic core that has a conducting metal wire looped or coiled around it in order to form an inductor.

We are proud of the craftsmanship of our engineers. All of our products are made right here in the United States and we promise that these items are created from high quality resources. Our electrical coils are unique and efficient.

Sag Harbor Industries, Inc. $$$

Established in 1973, Classic Coil Company is a Contract Manufacturer of electronic coils. We manufacture coils for a variety of industries; winding wire gauges from 4-58 AWG. We are ISO 9001-2015 certified, ITAR registered and DFARS Compliant. Our Engineering services allow us to assist with design, reduce cost, and increase efficiency in production. Call or visit our website to learn more about...

Classic Coil Company $$$

Since 1962, Torelco has been a supplier of electric coils and transformers of superior quality. We offer custom coils, solenoid coils, ferrite core coils & toroid wound coils to serve a range of industries. Markets served include medical, military, electronics, and industrial. When you work with us, our promise is to build to the exact specifications and meet the custom needs of our customers.

Torelco LLC $$$

Check out what’s new online at Precision Econowind, manufacturer of the highest quality custom coils at reasonable prices, with on time delivery. Serving the coil industry for over 30 years, we’re experienced with producing loudspeaker & medical industry coils, coils wound on customers’ bobbins/tooling; freestanding, flat wire, edge wound, square, rectangle & shaped coils. Submit your specs ...

Precision Econowind, Inc. $$$

Dufrane has produced Custom Toroidal Transformers for various applications and industries, including Medical, Aerospace and Defense, Rail, and other Industrial applications. Dufrane’s Toroidal transformers have a toroidal (ring or donut) shape. Toroidal coils exhibit superior electrical performance and are more efficient, preferred for applications which are sensitive to Electro Magnetic...

Dufrane Technologies, LLC $$$

Triad Magnetics has been in the electric coils industry for over 75 years. Giving us the knowledge and expertise to be one of the best in the industry. We have a wide range of electric coils and inductors as well as the ability to custom engineer and manufacture electric coils to our customer’s needs. Having served the needs of many industries for more than half a century, Triad believes its...

Triad Magnetics $$$
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placeholder image Sag Harbor Industries, Inc. Classic Coil Company Torelco LLC Precision Econowind, Inc. Dufrane Technologies, LLC Triad Magnetics

Ceramic Media

Types of Toroidal Coils

There are several categories of toroidal coils, and each type has a different usage from the next. The differences can be noted in the manufacturing materials or the general build of the coil core.

Ferrite Core Toroids

Ferrite cores are manufactured from a ceramic combined with metal oxide. Iron oxide and other metals like copper, cobalt, copper, zinc, nickel, and manganese are commonly used. The most commonly used cores are made from manganese-zinc ferrite and nickel-zinc ferrite. These cores have moderately low permeability and a small saturation flux density. This type of core is favorable because of its high electrical resistivity. Eddy currents are kept at a minimum in this type of toroid.

Ferrite Core Toroid

Powdered Metal Core Toroids

Cores made from powdered iron are made by combining and binding grains of metallic alloys and insulating material. The metal grains are pressed with the binders to form the desired shape or structure. The core will exhibit characteristics of the metal used. Molybdenum perm alloy or carbonyl iron metal cores are typical examples of manufactured powdered metal toroids.

Powdered Metal Toroid

Laminated Iron Alloy Toroids

Low-to-medium frequency transformers commonly use laminated iron alloy toroid coils. Laminated cores are fabricated by rolling the metal to form very thin sheets and stamping them into the desired shapes. The stampings are divided in between them with an insulating material. The problem of eddy currents is greatly minimized within the thickness of each lamination.

Laminated Iron Alloy Toroids

There are two common materials used in the manufacture of these toroids, and these are silicon iron alloy and nickel-iron alloy. Silicon iron toroids are used in high voltage transformers, and for other high-frequency uses, nickel-iron toroids are used.

Tape Wound Core Toroids

Tape wound toroid cores are almost the same as laminated core toroids. However, rather than stacking the ring-shaped laminations, the tape wound cores are manufactured from insulated metallic ribbons that are wound into a spiral. The toroid is then encapsulated with a thin sheet made of aluminum or plastic.

Tape Wound Alloy Toroids

Applications of Toroidal Coils

Toroidal coils are commonly used in medical equipment and machinery, telecommunications fields, music instruments, amplifiers, and nuclear fusion processes. Toroids are used in the confinement of plasma at high temperatures in the tokamak.

Advantages of Toroidal Coils

Toroid coils have a very high flux density. They can be properly operated at flux densities that are virtually greater than 14 kilogauss. Other transformers are best suited to operate between 11 and 14. They can also be placed near other electronic devices and equipment without the fear of possible interferences and inductive interactions.

Toroidal Coil Circuitry

Toroidal coils also have a significantly low mechanical hum. The toroid ensures low noise due to the absence of air gaps in its build. Toroids are also easily mounted on the designated place of usage because they are smaller than general transformers. Toroidal coils are also very dependable in the induction of electrical current because the windings and coils minimize moving wirings that tend to fail when stressed.

Disadvantages of Toroidal Coils

Toroid coils are very difficult to manufacture, and the winding process is very slow and expensive. Toroidal coils also make for complex components. The coils are also very sensitive to mechanical stress and can easily deform. Sudden temperature variations greatly affect the workability of these coils, as they are very prone to saturation.

Choosing the Proper Toroidal Coil Supplier

To ensure the most positive outcome when purchasing toroidal coils from a toroidal coil supplier, it is important to compare several companies using our directory of toroidal coil suppliers. Each toroidal coil company has a business profile page showing their areas of experience and capabilities, along with a contact form to directly communicate with the company for more information or request a quote. Review each toroidal coil business website using our patented website previewer for a better understanding of what each company specializes in. Then, use our simple RFQ form to contact multiple toroidal coil businesses with the same form.

Toroidal Coils Informational Video


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