Products & Materials - Magnetic Metals Corporation

Advanced-Grade Materials Used in Our Cores

malvcomm — Thu, 15 Dec 2022 21:47:25 +0000

Amorphous Alloys

Metallic glass materials without a crystalline structure and with better electrical conductivity than conventional materials

Benefits

High tensile strength.
Excellent resistance to fracture and corrosion.
Large amount of elastic deformation

Applications

For high frequency, low loss applications
Inductors
Energy storage inductors
Saturable cores

Cobalt Iron

Fe/Co is a soft magnetic material with an extremely high magnetization saturation.

Benefits

Best for applications requiring reduced size and weight

Applications

Aircraft generators,
Electric motors,
Magnetic bearings.

Microsil^TM

3% Si/Fe grain-oriented silicon iron alloy. It’s squareness ratio and gain is lower than for Square 50, while core losses are higher.

Benefits

Least expensive of the Square Loop materials.
Very high maximum flux.
Ideal for high power, relatively low frequency applications.

Applications

For high performance applications
Power Transformers,
Saturable Reactors,
Inverter Transformers,
Magnetic Amplifiers (Power),
Current Transformers,
Output Transformers.

Nanocrystalline Alloys

Materials comprised of single- and multi-phase polycrystalline structures that have higher magnetic properties than conventional materials.

Benefits

High strength and hardness.
Reduced elastic modules.
Large heat capacity and thermal expansion coefficient.

Applications

For high frequency applications,
Current transformers,
GFCI transformers,
Inductors,
Industrial controls,
For wide range temperature applications.

Square 50

50% Ni/Fe/ grain-oriented alloy. It has B_m as well as cores losses so low it can be used in higher frequency applications than the silicon steels.

Benefits

Highest squareness ratio possible (lowest saturated reactance).
Very high gain.
Ideal wherever an extremely square loop/close tolerance material is required.

Applications

Bi-stable switching devices,
Inverter transformers,
High performance power magnetic amplifiers
Linear current transformers,
Timing devices,
Driver transformers.

Square 80

80% Ni/Fe/Mo. It is a low coercive force material with similar characteristics to Supermalloy^TM

Benefits

Good squareness and high gain.
Low core losses.

Applications

Low power, high efficiency inverter transformers,
Low level, high frequency magnetic amplifiers & modulators,
Pulse transformers.

Super Square 80

80% Ni/Fe/Mo. It has higher maximum flux density, gain, and squareness ratio than Square 80.

Benefits

Provides remarkable core uniformity.
Very slight increase in coercive force.

Applications

Wherever a high degree of thermal stability is required for certain magnetic characteristics like Bm/Br, H, δH.

Supermalloy^TM

80% Ni/Fe/Mo. This alloy is processed for exceptionally high initial permeability.

Benefits

Designed for very low level or high value applications.

Applications

Very low-level Signal Transformers,
Low level Magnetic Preamplifiers,
High value Inductors without superimposed direct currents,
Precision Current Transformers.

Supermendur^TM

49% Co/49% Fe/V. It is the highest flux density material available in tape wound cores.

Benefits

Ideal wherever size and weight are a major design consideration.

Applications

Power Transformers,
Power Magnetic Amplifiers,
Inverters.

SuperPerm^TM 49

50% Ni/Fe/ Alloy. This material has characteristics that fall between Silicon Steel and 80% Ni/Fe/Mo.

Benefits

Provides high initial permeability.
Has high maximum flux.

Applications

Current Transformers,
Proportioning Reactors,
High quality/wide frequency Response Transformers,
Medium power Magnetic Amplifiers.

SuperPerm^TM 80

80% Ni/Fe/Mo. Similar to Supermalloy^TM but processed for pulse and high frequency performance.

Benefits

Designed for very low-level signal applications.
Ideal for high frequency applications.

Applications

Very low-level signal transformers,
Low level and high frequency magnetic preamplifiers,
High value/high frequency inductors.

The post Advanced-Grade Materials Used in Our Cores first appeared on Magnetic Metals Corporation.

Amorphous Cores

malvcomm — Thu, 17 Nov 2022 00:00:38 +0000

Amorphous Cores

Our amorphous-alloy cores provide a wider range of high frequency properties and lower core losses than other soft magnetic materials.

Amorphous Alloys are metallic glass materials without a crystalline structure. Amorphous-Alloy Cores provide better electrical conductivity, higher permeability and magnetic density, and efficient operation over a wider temperature range than cores made from conventional materials. Smaller, lighter, and more energy-efficient designs are possible for transformers, inductors, invertors, motors, and any device requiring high frequency, low loss performance.

Advantages of using amorphous cores:

High permeability
High magnetic density
Reduced distribution and core losses
Wide range of frequency properties
Low coercivity forces

Low no-load loss
Low temperature rise
Affordably priced
Excellent resistance to corrosion
High harmonic wave tolerances

Magnetic Metals produces Tape Wound Toroidal and Tape Wound Cut Cores using Advanced-Grade Amorphous Alloys, customized to meet your design and application specifications. We can tailor the magnetic properties and characteristics – especially frequency, permeabilities and pulse properties – to your specific requirements. Email us at webinfo@magneticmetals.com or call (800) 331-0278 to discuss which soft magnetic material and core design will give you maximum performance.

Typical Applications:

– Transformers for electric
   grid power and distribution
– Current transformers
– High frequency, energy
   storage inductors
– Saturable cores
– Motors
– Invertors
– High-frequency electronic
   devices
– GFCI’s (Ground Fault
   Circuit Interrupters)

The post Amorphous Cores first appeared on Magnetic Metals Corporation.

Low-Cost C-I Core

malvcomm — Wed, 16 Nov 2022 23:37:34 +0000

C-I Core

A Low Cost Solution to a New Generation in Transformer Design

Transformers used for the distribution and control of electrical energy consist of a primary and secondary copper wound coil carrying a magnetizing current surrounding an iron core which is used for the transferring of power from the primary to the secondary coil.

The iron core is normally made of thin gauge laminated steel either of low cost stamped laminations in the assembly form of EI’s or EE’s (see Figure 1) or similar laid up structures sometimes in a more costly tape wound double cut core assembly as shown in Figure 2.

Stamped laminations are usually made of .006″ thick material and can go as high as .025″, the cost for producing the lamination is very low, but the high cost comes from the stamping dies used to stamp the laminations and also the final assembly by the customer. While cut cores can be made of very thin magnetic steel strip (such as .001″ and can go as high as .014″) wound over simple low cost mandrels, heat treated, impregnated, and finally cut into two pieces as a completed set and ready for customers use.

The new core configuration called the C-I Core ( Patent pending ) combines the advantage of low cost laminations requiring expensive tooling and those of cut cores which are more expensive to manufacture but requires only simple low cost tooling.

The C-I core configuration is made of one cut core (rectangular, toroidal or any other shape) and one laminated “I” bar as shown in Figures 3a & 3b.

The core in its final assembly has the same shape as an EL, EI, or F stamped lamination and is similar to the configuration of a double C-core.

The C-I core can be made of .001″ thick material or greater (up to .014″), using Grain Oriented Silicon iron, Nickel iron or other Crystalline steels. It offers the designer of transformers and inductors flexible dimensions, high frequency range up to 20KHz, and low cost tooling.

THE ADVANTAGES OF THE C-I CORE ARE DISCUSSED AS FOLLOWS:

Cost less than conventional double cut core. Producing one cut core and one “I” bar requires less tooling and is less time consuming than two cut cores, therefore the C-I core is less expensive to make than two cut cores.
The ease of copper coil winding. Since the “‘I” bar is straight and has flat surfaces, the copper coil can be wound directly onto the “I” bar without having to make a bobbin. This will reduce the cost and simplify the production of prototypes significantly.
Reduction of the winding resistance. Since the “I” bar is removable, it can be smoothed out around the four edges (optional ) where the copper wires are wound which would reduce the the wire length and ultimately reduce the resistance of the winding.
Adjustable air gaps: For Inductors requiring air gaps, the insulation can be placed onto the “I” section to be used as air gaps.
Tighter tolerance: The tolerance only applies to one cut core instead of two as in the shell type, and the “I” bar is made of stacked up lamination in which the tolerance can be more accurately controlled to fit the bobbin.
Efficient assembly time: Normally the transformer using double cut cores required two clamping bands on each individual core as shown in Figure 2. The C-I core is held together by one clamping band as in Figures 3a & 3b.

DESCRIPTION OF THE C-I CORE

The C-I core is made up of two “C” sections of a cut core and one laminated “I” bar put together as shown in Figure 4.

The cut core is a normal cut “C” core with dimensions D, E, F, G, A, B as indicated in Magnetic Metals’ cut core catalog and shown below in Figure 5.

The laminated “I” bar is made up of laminations stacked up and impregnated with the following dimension as shown in Figure 6.

The stripwidth of the “I” bar D1 = 2E, the laminations are stacked up to a thickness of E1 = D, and the length of the “I” bar L = A (D, E, and A are dimensions of the cut core). For best mechanical and electrical performance, the dimensions of the “I” section will be built to the norminal D, E, and A dimensions plus there tolerance.

C-I cores have the same design equations as cut cores and laminations. The equations are: Power VA = K1AwAcB

Inductance L = K2AwAcu

Where Aw is window area, and Ac = 2ExD is the cross sectional area of the core.

If you have the need for additional technical information or samples regarding this concept, please call Magnetic Metals Corporation, Anaheim, CA at (714) 828-4625, or contact us at info@magneticmetals.com.

	Available Material Thickness	Frequency Range	Relative Core Cost	Bobbin Cost	Relative Assembly Cost	Tooling Cost	Application	Advantage	Disadvantage
EE/EI/F Lamination	6-25 mil	50-400 Hz	1	Low	3	Very High	Power X-formers, Current X-formers, Inductors, Chokes	Inexpensive material and parts, better control of tight tolerance	Limited thickness, expensive asssembly and tooling
Shell Type Double C Core	1-14 mil	50-20 KHz	4	High	2	Fair	Power X-formers, Current X-formers, Inductors, Chokes	Inexpensive tooling, easy assembly, available in many sizes	More expensive than laminations, wide tolerance
C-I Core	1-14 mil	50-20 KHz	3	Low or none (can wind directly on “I” bar)	1	Low	Power X-formers, Current X-formers, Inductors, Chokes	Inexpensive tooling, available in many sizes, easy assembly, wind directly on “I” bar	Wider Tolerance than lamination but better control than Shell Type C Core

The post Low-Cost C-I Core first appeared on Magnetic Metals Corporation.

Low Loss “A-Core”

malvcomm — Wed, 16 Nov 2022 22:20:24 +0000

Low Loss “A-Core”

A NEW GENERATION IN TRANSFORMER DESIGN

Tape wound cut cores throughout the core manufacturing industries are currently being produced with a straight cut along the horizontal plane as core shown in Figure 1 below.

The core is cut in this manner so that a coil designed with specific winding turns and dimensions can be placed onto the leg of the core as part of an assembly unit for a transformer (see Figure 2).

Cut cores require large magnetizing current that is necessary to magnetize the core and also to jump across the air gap between the cut segments of area D x E This current is often referred to as the Excitation Current (Iex ) and is defined as:

Equation 1

Equation 2

wt =	Weight of the core in pounds
VA/# =	Volt Ampere / pound of core material
V =	Voltage applied to the winding N
B =	Flux Density
eg =	Effective air gap between the cut segments
SF =	Stacking Factor
N =	Number of Turns of primary winding
Imat =	Current to magnetize material
Igap =	Current to drive flux over air gap

Equations (I) and (2) show that the excitation current Iex is dependent on the material quality (VA/#), and the effective air gap eg between the cut segments.

For many applications such as Power Transformers, AC Inductors, and Current Transformers etc., it is necessary to minimize the current Iex of the core. Therefore, besides selecting the right material for the application, the air gap of the cores has to be kept as small as possible to achieve a maximum efficiency rating. Usually core manufacturers lap the mating core surfaces to reduce the air gap, but lapping has its limitations, and will greatly increase the cost of the core.

Example: A core weighing 0.5 to 2.0 lbs normally has air gap of .001″. By precision lapping the two segments of the core, the typical gap achievable would be .0005″. This is only a small difference in the gap, but the added cost for the lapping is significant.

The Cut-Angle Core or A-Core (patent pending)

Figures 3 and 4- will minimize the effective air gap eg in a low cost manner by increasing the matching surface area of the two segments and thus reducing the reluctance. The matching surface area of a straight cut core is defined as: A = Dx E. The matching surface area of a Cut angle (Figures 3 and 4) is defined as:

The reluctance of a straight cut core is:

The reluctance of a Cut Angle core is:

The current acquired by air gap of a straight cut core is:

The current acquired by air gap of a Cut Angle core is:

Equation (3) above shows the current acquired by air gap of an Angle cut core is reduced by a factor of cosa (Cosa is always smaller than 1, therefore I’gap is always smaller than I gap).

Therefore, the excitation current of a Cut Angle core becomes:

We also found that cores with an angle cut dramatically reduce the acoustical noise when compared to a straight cut core, which is a very desirable property. The Cut Angle core is also applicable for Three Phase cores (Figures 5&6).

The Angle-Cut core can be banded by using an “L” bracket (see Figure 7) to support the two halves from slipping during the banding process. The final assembley includes core, bobbin, “L” bracket, and band as shown in Figure 8.

If you have the need for additional technical information or samples regarding this concept please contact Magnetic Metals Corporation, Anaheim, CA at (714) 828-4625.

The current I’gap of a core with a 45° cut is 30% less when compared to a straight cut core, and I’gap of a core with a 60° cut is less than 50% when compared to the same core having a straight cut. This we have experimentally verified.

The post Low Loss “A-Core” first appeared on Magnetic Metals Corporation.

Tape Wound Cut Cores

malvcomm — Wed, 16 Nov 2022 21:40:24 +0000

Tape Wound Cut Cores

Tape wound cut cores are ideal for transformer design engineers who require one to several thousand transformers in shapes that are unavailable in standard lamination sizes. They also are ideally suited where weight or dimensional requirements are critical and have to be reduced, including chokes, pulse applications and current transformers.

Magnetic Metals’ Tape Wound Cut Cores Offer:

The advantages of using Microsil™, including its excellent magnetic properties of grain oriented silicon iron in the rolling direction;
Lighter weight for same VA power rating;
The highest flux densities available – through 21.0 kilogauss – provided by our Supermendur™ material
Air gap that can be easily adjusted for specific choke design;
Outstanding pulse performance, including high pulse permeability with or without reset;
Operating frequency up to 40 kilohertz with thin gauge core material;
Operating temperatures up to 350 F;
Reduced core noise;
Easy selection and low assembly costs;
Wide range of core mandrels available from stock for quick delivery;
High quality assurance of your finished parts from our proven designs and advanced manufacturing facility;
Special sizes or shapes that can be readily manufactured to meet your custom or standard designs.

Available Shapes, Sizes and Materials

Magnetic Metals can produce almost any size single-phase or 3-phase tape wound transformer core without expensive tooling. Special geometric shapes and assembly configurations are available at minimal costs. Cores are manufactured with new computer-controlled precision equipment or with traditional tape wound cut core manufacturing procedures.

Materials include:

Amorophous alloys;
Cobalt iron;
Microsil™;
Nanocrystalline alloys;
Square 50 (Nickel iron);
Supermalloy™;
SuperPerm™ 80 (Nickel iron).

Visit our Advanced Grade Materials page for more information.

Core Construction

Magnetic Metals tape wound cut core manufacturing processes are designed to produce transformer cores having the lowest possible losses and magnetizing currents. Where required, special selection of steel is made to meet exacting specifications for very low loss, high pulse permeability, etc. Through improved cutting procedures and butt end preparation, the air gap at the face is kept to an absolute minimum. As a result, the assembled cores exhibit exceptionally low hum and low exciting current.

The finished product is final tested to both mechanical and electrical requirements as described in the EIA Standard for Cut Cores RS-217A and according to Magnetic Metals’ own stringent test requirements for cut cores.

Electrical Characteristics

Magnetic Metals cut core manufacturing processes are designed to produce transformer cores having the lowest possible losses and magnetizing currents. Where required, special selection of steel is made to meet exacting specifications for very low loss, high pulse permeability, etc. Through improved cutting procedures and butt end preparation, the air gap at the face is kept to an absolute minimum. As a result, the assembled cores exhibit exceptionally low hum and low exciting current.

Login or register to download the
Tape Wound Toroidal Core Design Manual
for material performance data, core selection guide, and ordering information

Single phase cut core

3-Phase cut core

The post Tape Wound Cut Cores first appeared on Magnetic Metals Corporation.

Tape Wound Toroidal Cores

malvcomm — Tue, 15 Nov 2022 17:52:02 +0000

Tape Wound Toroidal Cores

The tape wound toroidal core approaches the perfect magnetic circuit configuration as well as permitting the most efficient application of high permeability magnetic alloys. The physical and magnetic characteristics of the toroidal shape reveal many features which contribute to this near-perfect circuit.

For instance, the air gap in the magnetic path is so small that it can be considered non-existent. This minimizes losses, fringing, leakage, distortion, and decreases the magnetizing force necessary to produce a given flux within the material.

In a toroidal core and coil assembly, the entire magnetic path is contained within the electrical winding, further minimizing leakage flux and increasing winding-to-winding coupling. Tape wound cores do generate a small flux in the axial direction, however, this leakage flux can be contained by ring laminations assembled to the top and bottom of the core.

The tape wound core configuration also provides a good degree of self-shielding from external magnetic fields. The single, uniform, magnetic path causes any entering magnetic field to split into two and induce equal but opposite voltages in the two halves of a uniformly distributed winding. Thus, there tends to be no voltage apparently induced in the total winding.

Available Shapes, Sizes and Materials

Magnetic Metals manufactures tape wound toroidal cores and other shapes for power transformers, inductors, drive transformers, saturable reactors, magnetic amplifiers, current transformers, converters and inverters.

We offer a wide range of sizes and materials for tape wound transformer cores. Almost any size can be made for minimum tooling costs. A wide selection of cases or coating materials are also available to meet your requirements.

The magnetic materials used for tape wound cores can be classified in two broad categories: “Square Loop” or “Round Loop”. This classification is made to the relative shape of the B-H loop.

Square loop versions tend to have:

Higher maximum flux capabilities (Bm)
Wider loops (greater Hc loop width at zero flux)
Higher squareness ratios (Br/Bm) – ratio of residual flux density to maximum flux density
Higher core losses

Round loop versions tend to have:

Lower Bm
Narrower loops
Lower squareness ratios
Higher initial permeability
Lower core losses

Our technical design engineers are always available to help you select the optimum material for your application, and then incorporate the material’s characteristics in the final design.

Square Loop materials include:

Amorophous alloys;
Cobalt iron;
Microsil™ silicon iron alloy;
Nanocrystalline alloys;
Square 50;
Square 80;
Super Square 80;
Supermendur™.

Round Loop materials include:

Supermalloy™;
SuperPerm™ 49;
SuperPerm™ 80.

Visit our Advanced Grade Materials page for more information.

Core Construction

Tape wound toroidal cores are fabricated on specially designed machines which wind insulated tape onto a mandrel under controlled tension to provide an extremely uniform cross-section. The wound cores are then annealed in a controlled atmosphere of hydrogen/nitrogen. This develops the specific magnetic characteristics required for the application.

Annealed cores are sensitive to mechanical stresses in varying degrees depending upon the alloy. These stresses cause changes in the magnetic characteristics of the material which may severely alter the performance of the finished core. To prevent these changes from taking place, the annealed tape cores are housed within cases which protect them from the strains of electrical winding and other external disturbances.

These cases are fabricated of various materials depending upon the intended application: plastics; phenolic; nylon; glass-reinforced nylon; and aluminum are typically used.

The non-metallic cases (glass-filled nylon, phenolic, nylon) are the most widely used. The glass filled nylon case has proven superior to the phenolic case because of its greater strength. Aluminum cases provide greater environmental protection and this quality can be further enhanced by the application of an epoxy finish over the case.

A damping medium fills the space between the core and the case to minimize the motion of the core within the case, thus reducing the possibility of change in electrical characteristics under shock and vibration.

Pulse or High Frequency Applications

Magnetic Metals has developed a special process whereby tape wound core pulse or high frequency performance is optimized. To ensure that cores intended for pulse applications are manufactured under this process, the suffix “P” should be added to the standard core number, i.e., 11P4601-P, when ordering.

Gapped Toroidal Cores

The design of a storage choke or transformer which also carries direct current normally requires air gaps which prevent the core from being magnetized by the dc current above 1/2 B max. An air gap in a core has the effect of flattening/ shearing the B-H loop of the material, lowering the residual flux and the permeability, extending the incremental a.c. permeability to higher values of B and H. Precise control of the inductance L, or the remanence Br is therefore possible with gapped toroids.

Constant Current Flux Reset Test

The Constant Current Flux Reset (CCFR) test is widely used to evaluate core performance for magnetic amplifier use. The test is described in IEEE Standard 106. The ac excitation is usually specified at 400 Hertz, but frequencies between 60 and 6000 Hertz may also be specified. Our technical design engineers will ensure maximum flux change and reset as required for your magnetic amplifier specifications.

Login or register to download the
Tape Wound Toroidal Core Design Manual
for material performance data, core selection guide, and ordering information

Cut-a-way view of an aluminum-cased tape wound core

Examples of TWTC magnetic circuit configurations

TWTC magnetic circuit configurations within finished transformers

The post Tape Wound Toroidal Cores first appeared on Magnetic Metals Corporation.

Magnetic Transformer Cores

malvcomm — Tue, 15 Nov 2022 17:40:48 +0000

Magnetic Transformer Cores

We offer the widest range of types and thicknesses of materials for magnetic metal components in our industry, enabling us to produce many varieties of cores: tape, cut, A and C-I. Additionally, our coating, slitting, core winding, annealing and assembly services allow us to meet the manufacturing requirements of almost any magnetic metal product.

The post Magnetic Transformer Cores first appeared on Magnetic Metals Corporation.

Products & Materials - Magnetic Metals Corporation

Advanced-Grade Materials Used in Our Cores

Amorphous Alloys

Cobalt Iron

MicrosilTM

Nanocrystalline Alloys

Square 50

Square 80

Super Square 80

SupermalloyTM

SupermendurTM

SuperPermTM 49

SuperPermTM 80

Amorphous Cores

Amorphous Cores

Our amorphous-alloy cores provide a wider range of high frequency properties and lower core losses than other soft magnetic materials.

Advantages of using amorphous cores:

Low-Cost C-I Core

C-I Core

A Low Cost Solution to a New Generation in Transformer Design

THE ADVANTAGES OF THE C-I CORE ARE DISCUSSED AS FOLLOWS:

DESCRIPTION OF THE C-I CORE

Low Loss “A-Core”

Low Loss “A-Core”

A NEW GENERATION IN TRANSFORMER DESIGN

The Cut-Angle Core or A-Core (patent pending)

Tape Wound Cut Cores

Tape Wound Cut Cores

Magnetic Metals’ Tape Wound Cut Cores Offer:

Available Shapes, Sizes and Materials

Core Construction

Electrical Characteristics

Tape Wound Toroidal Cores

Tape Wound Toroidal Cores

Available Shapes, Sizes and Materials

Core Construction

Pulse or High Frequency Applications

Gapped Toroidal Cores

Constant Current Flux Reset Test

Magnetic Transformer Cores

Magnetic Transformer Cores

Microsil^TM

Supermalloy^TM

Supermendur^TM

SuperPerm^TM 49

SuperPerm^TM 80