Description

Fe-Ni based soft magnetic cores (toroidal, laminated, yoke) in high permeability, high saturation, rectangular loop, and constant permeability grades. Ideal for current transformers, power conversion, and magnetic amplifiers. Custom sizes available.

Soft Magnetic Cores for Transformers, Inductors & Magnetic Components

Greenergy Materials supplies soft magnetic cores for transformers, inductors, chokes, current transformers and other electromagnetic components. Available core structures include toroidal, laminated, yoke and other customized magnetic core configurations, with material selection based on frequency, magnetic flux density, core loss, saturation performance and operating temperature.

We support customized magnetic core dimensions, materials, shapes and performance requirements for industrial and electronic applications.

What Are Soft Magnetic Cores?

A soft magnetic core is a magnetic component designed to provide a low-reluctance path for magnetic flux while minimizing undesirable residual magnetism and magnetic losses.

Soft magnetic cores are widely used in:

• Transformers

• Inductors

• Chokes

• Current transformers

• Voltage transformers

• Electromagnetic actuators

• Magnetic amplifiers

• Filters

• Power electronics

• Industrial control equipment

The core material and core geometry directly affect magnetic performance.

For this reason, selecting a magnetic core requires consideration of both material properties and core structure.

Soft Magnetic Core Types

Greenergy Materials can evaluate different soft magnetic core structures according to the customer's application.

Toroidal Magnetic Cores

Toroidal cores have a closed ring-shaped magnetic path.

Their continuous magnetic path can help reduce magnetic leakage and provide compact magnetic construction.

Typical applications include:

• Toroidal transformers

• Toroidal inductors

• Current transformers

• Common-mode chokes

• EMI filters

• Power electronics

• Audio transformers

Toroidal structures can be manufactured from wound magnetic strip, powder materials or other magnetic materials depending on the operating frequency and required magnetic properties.

Laminated Magnetic Cores

Laminated cores are constructed from multiple thin magnetic sheets separated by electrical insulation.

The lamination structure reduces the effective area available for eddy-current circulation and is widely used in lower-frequency magnetic equipment.

Typical configurations include:

• EI cores

• UI cores

• EE cores

• Stacked laminations

• Custom punched laminations

Laminated silicon-steel cores are widely used in power-frequency transformers and inductors, while other soft magnetic materials can be selected for different frequency and magnetic-performance requirements.

Yoke Cores

A yoke core forms part of a magnetic circuit and provides a low-reluctance path connecting magnetic limbs or poles.

Yoke structures are commonly used in:

• Transformers

• Electromagnetic devices

• Magnetic actuators

• Relays

• Current transformers

• Custom magnetic circuits

The yoke geometry can be optimized according to magnetic flux distribution, mechanical dimensions and assembly requirements.

Tape-Wound / Strip-Wound Cores

Tape-wound cores are produced by winding thin magnetic strip into a controlled core geometry.

The winding process can provide a continuous magnetic path and is particularly useful for selected high-permeability and low-loss magnetic materials.

Potential applications include:

• Current transformers

• Precision transformers

• Inductors

• Chokes

• Power electronics

• High-efficiency magnetic components

Strip-wound construction is used with materials such as silicon steel, amorphous alloys and other soft magnetic ribbons depending on the application.

Soft Magnetic Core Materials

Core geometry is only one part of magnetic core selection.

The magnetic material determines important characteristics such as:

• Permeability

• Saturation flux density

• Coercivity

• Core loss

• Electrical resistivity

• Temperature stability

• Frequency capability

Different applications require different combinations of these properties.

Fe-Ni Soft Magnetic Alloy Cores

Nickel-iron soft magnetic alloys are suitable for applications requiring high permeability and specialized magnetic characteristics.

Potential applications include:

• Precision transformers

• Current transformers

• Magnetic sensors

• Magnetic shielding

• Audio transformers

• Inductors

• Electromagnetic components

Greenergy Materials supplies multiple Fe-Ni soft magnetic alloy grades for different performance requirements.

Related materials include:

• 1J66 constant permeability alloy

• 1J46 / 1J50 / 1J54 high-permeability alloys

• 1J79 / 1J85 high-initial-permeability alloys

  
  

Fe-Co Soft Magnetic Alloy Cores

Fe-Co soft magnetic alloys are used when high saturation magnetic induction is a major design requirement.

For example, 1J22 is positioned as a high-saturation-induction Fe-Co-V soft magnetic alloy.

Potential applications include:

• High-flux magnetic circuits

• Electromagnetic actuators

• Motors

• Generators

• Transformers

• High-field magnetic components

See also:

1J22 High Saturation Induction Soft Magnetic Alloy

Silicon Steel Magnetic Cores

Silicon steel is widely used in laminated magnetic cores for power-frequency transformers and related electrical equipment.

Its lamination structure helps control eddy-current losses, making it suitable for lower-frequency transformer applications.

Common structures include:

• EI cores

• UI cores

• EE cores

• Laminated yoke cores

• Stacked transformer cores

Amorphous and Nanocrystalline Magnetic Cores

Amorphous and nanocrystalline magnetic materials can provide attractive combinations of magnetic permeability, low loss and frequency performance for selected power and electronic applications.

They may be considered for:

• High-efficiency transformers

• Current transformers

• Chokes

• Power inductors

• High-frequency magnetic components

The appropriate material depends on operating frequency, flux density, temperature and loss requirements.

Soft Magnetic Cores for Transformers

The transformer core provides the magnetic path that couples the primary and secondary windings.

Core selection affects:

• Magnetizing current

• Core loss

• Saturation behavior

• Temperature rise

• Efficiency

• Frequency response

For power-frequency transformers, laminated magnetic cores are widely used.

For other transformer designs, toroidal, tape-wound, ferrite, amorphous or nanocrystalline cores may be more appropriate depending on the operating frequency and performance requirements.

Soft Magnetic Cores for Inductors

An inductor stores energy in its magnetic field and uses the core to increase inductance and control magnetic flux.

Important core-selection factors include:

• Inductance

• Saturation current

• Core loss

• DC bias

• Frequency

• Temperature

• Air-gap requirements

For power inductors, common material families include ferrite, powdered metal, strip-wound alloys and laminated materials. Their performance differs significantly in core loss, saturation behavior, DC-bias performance and cost.

Soft Magnetic Cores for Current Transformers

Current transformer cores require controlled magnetic behavior because the core directly influences:

• Transformation accuracy

• Excitation current

• Saturation characteristics

• Phase error

• Measurement accuracy

Depending on the application, high-permeability Fe-Ni alloys, nanocrystalline materials, amorphous alloys or other soft magnetic materials may be considered.

For precision current transformers, the material grade, annealing condition, core dimensions and magnetic test conditions should be specified together.

Soft Magnetic Cores for Chokes and Filters

Magnetic chokes are used to limit or filter unwanted current components.

Core selection depends on:

• AC frequency

• DC bias

• Required inductance

• Saturation behavior

• Core loss

• Temperature rise

For power inductors and chokes, the choice between ferrite, powdered metal, strip-wound material and laminated cores depends strongly on frequency and DC-bias conditions.

How to Choose the Right Soft Magnetic Core

Choosing a magnetic core based only on its shape is not sufficient.

A better selection process includes six steps.

Step 1: Define the Application

Determine whether the core will be used for:

• Transformer

• Inductor

• Choke

• Current transformer

• Magnetic sensor

• Actuator

• Filter

• Magnetic amplifier

Step 2: Define the Operating Frequency

Frequency is one of the most important material-selection factors.

Typical applications may range from:

• Power frequency

• Audio frequency

• Intermediate frequency

• Switching frequency

• High-frequency applications

Higher frequency generally increases the importance of electrical resistivity and core-loss behavior.

Step 3: Define the Flux Density

Determine:

• Maximum flux density

• Peak flux density

• AC flux density

• DC bias

• Required saturation margin

A material with high saturation induction may be preferred when the magnetic circuit operates at high flux density.

Step 4: Define Core Loss

Core loss can include:

• Hysteresis loss

• Eddy-current loss

• Other frequency-dependent magnetic losses

The required material should therefore be selected according to the operating frequency and waveform.

Step 5: Define Core Geometry

Select the appropriate structure:

• Toroidal

• EI

• EE

• UI

• Yoke

• E-core

• U-core

• Tape-wound

• Custom geometry

Step 6: Define Mechanical and Dimensional Requirements

Specify:

• Outer diameter

• Inner diameter

• Core height

• Window dimensions

• Thickness

• Magnetic path length

• Cross-sectional area

• Tolerances

• Surface condition

Toroidal vs Laminated Magnetic Cores

A toroidal core is not automatically better than a laminated core. The appropriate geometry depends on frequency, power, flux density, winding requirements, thermal constraints and cost.

Magnetic Core Material Selection by Application

This table should be treated as a material-selection starting point rather than a universal rule because the optimum material depends on operating conditions.

Core Geometry and Magnetic Performance

Core geometry affects the magnetic circuit.

Important geometric parameters include:

• Magnetic path length

• Effective cross-sectional area

• Window area

• Air gap

• Core volume

• Winding area

For example, toroidal cores provide a continuous magnetic path, while laminated E-I structures provide a practical assembly configuration for many transformer designs.

The geometry should therefore be optimized together with the selected material.

Air Gap in Soft Magnetic Cores

An air gap can be deliberately introduced into a magnetic core when the application requires controlled inductance and improved tolerance to DC bias.

Air gaps are particularly relevant to many inductor designs.

However, an air gap can also introduce:

• Fringing flux

• Additional magnetic reluctance

• Localized loss

• Winding-related effects

The appropriate gap should therefore be determined from the required inductance, current and saturation characteristics.

Magnetic Core Manufacturing

Depending on the material and core type, manufacturing processes may include:

Material Preparation

Selection and inspection of the magnetic strip, sheet or other raw material.

Cutting and Forming

Materials may be:

• Slit

• Cut

• Stamped

• Laminated

• Wound

• Formed

Core Assembly

Depending on the design:

• Stacking

• Winding

• Bonding

• Clamping

• Annealing

• Gap formation

Heat Treatment

Heat treatment may be required to achieve the required magnetic properties, especially for specialized soft magnetic alloys.

Final Inspection

Finished cores can be evaluated for:

• Dimensions

• Magnetic properties

• Surface condition

• Core loss

• Inductance

• Permeability

• Insulation where applicable

Quality Control for Soft Magnetic Cores

A reliable magnetic core supplier should evaluate both the material and the finished core.

Material Inspection

Check:

• Chemical composition

• Material grade

• Thickness

• Width

• Electrical resistivity

• Mechanical properties

Magnetic Testing

Depending on application:

• Initial permeability

• Maximum permeability

• Saturation flux density

• Coercive force

• Core loss

• AC magnetic properties

• DC bias performance

Dimensional Inspection

Check:

• Outer diameter

• Inner diameter

• Height

• Thickness

• Window dimensions

• Air gap

• Tolerances

Finished Core Testing

For selected products:

• Inductance

• AL value

• Core loss

• Temperature rise

• Insulation

• Mechanical integrity

Custom Soft Magnetic Core Manufacturing

Greenergy Materials can evaluate customized soft magnetic core requirements according to:

• Core material

• Core shape

• Core dimensions

• Magnetic properties

• Operating frequency

• Flux density

• DC bias

• Core loss

• Air gap

• Heat treatment

• Surface treatment

• Quantity

Custom core geometries may include:

• Toroidal cores

• Laminated cores

• EI cores

• EE cores

• UI cores

• Yoke cores

• Tape-wound cores

• Custom magnetic circuits

For a technical quotation, provide the application, operating frequency, core dimensions, magnetic requirements and quantity.

Soft Magnetic Core Specification Checklist

Before requesting a quotation, prepare the following information:

The more complete the specification, the easier it is to select the appropriate material and core geometry.

Why Choose Greenergy Materials for Soft Magnetic Cores?

Greenergy Materials specializes in high-performance special alloys, magnetic materials and electronic components, with customized solutions for industrial customers.

For soft magnetic core projects, customers can discuss:

• Material selection

• Core geometry

• Magnetic performance

• Dimensional requirements

• Heat treatment

• Inspection requirements

• Custom production

Our product portfolio also includes specialized soft magnetic alloys that can be evaluated for different core applications.

Frequently Asked Questions

What is a soft magnetic core?

A soft magnetic core is a magnetic component made from a material that can be magnetized and demagnetized relatively easily. It provides a controlled magnetic path in transformers, inductors, chokes and other electromagnetic devices.

What are soft magnetic cores used for?

Common applications include transformers, inductors, chokes, current transformers, magnetic sensors, electromagnetic actuators and filters.

What is the difference between a toroidal and laminated core?

A toroidal core has a ring-shaped continuous magnetic path, while a laminated core is assembled from stacked insulated magnetic sheets. The appropriate design depends on application, frequency, power, flux density and manufacturing requirements.

Which magnetic core is best for transformers?

There is no single best core type for every transformer. Silicon-steel laminations are widely used for power-frequency applications, while ferrite, amorphous, nanocrystalline, Fe-Ni and other materials may be appropriate for different frequency and performance requirements.

Which magnetic core is best for inductors?

The choice depends on frequency, DC bias, inductance, saturation current and core loss. Ferrite, powdered metal, strip-wound alloys and laminated cores are all used in different inductor designs.

What is a toroidal magnetic core?

A toroidal magnetic core is a ring-shaped core around which a winding can be placed. Its closed magnetic path can help reduce leakage flux and provide a compact magnetic structure.

What is a laminated magnetic core?

A laminated magnetic core consists of thin magnetic sheets stacked together with insulation between laminations. This construction helps reduce eddy-current losses and is widely used in lower-frequency magnetic applications.

Can soft magnetic cores be customized?

Yes. Core material, geometry, dimensions, air gap, magnetic properties and inspection requirements can be customized subject to technical evaluation.

Can you supply the magnetic material and finished core?

Depending on the project, material selection and finished-core requirements can be evaluated together. Customers should provide the application, dimensions and magnetic specifications.

What information is required for a quotation?

At minimum, provide the application, core type, dimensions, operating frequency, flux density or current, material preference, quantity and required magnetic performance.

Request a Custom Soft Magnetic Core

Looking for toroidal, laminated, yoke or custom soft magnetic cores for transformers, inductors, chokes or current transformers?

Send us:

Application + Core Type + Material + Dimensions + Frequency + Flux Density/Current + Quantity

Greenergy Materials can help evaluate the appropriate soft magnetic core material, geometry and manufacturing specification for your application.

Contact us for technical support, custom core development and quotation.