WOUND CORES STRIP WOUND CORES STRIP WO x www.mag-inc.com Visit Magnetics’ website for a wealth of easy to access information on soft magnetic cores and materials… All product specifications for Magnetics’ Ferrite Cores, Powder Cores and Strip Wound Cores can be found quickly by using the menu driven product locator. Magnetics’ Digital Library contains all of the company’s technical bulletins, white papers and design manuals, which can be viewed on-screen or downloaded. The Software section of the website provides access to the Magnetics’ software design aids for designing Common Mode Filters, Current Transformers, Inductors and MagAmps. Contact information for Magnetics’ global distribution network, including access to STOCKCHECK, an easy way to check distributor inventory via the web. Contact Magnetics P.O. Box 11422 Pittsburgh, PA 15238-0422 web: www.mag-inc.com Phone: 412-696-1300 or 1-800-245-3984 Fax: 412-696-0333 email: [email protected] 2 MAGNETICS – www.mag-inc.com MAGNETICS STRIP WOUND CORES INDEX INTRODUCTION History ................................................1 HISTORY OF THE STRIP WOUND CORE Materials and Applications ................2 Magnetics pioneered Strip Wound Cores. Although the groundwork for the formation of modern magnetic devices was Tape Wound Cores ............................4 laid by German military in World War I, it was after World War II that tape Bobbin Cores ....................................8 wound cores had their beginnings as electronics opened the way to new weapons systems. The Naval Ordnance Laboratory in Washington, DC turned Cut Cores and Special Cores............11 its attention to facets of magnetism in devices where the vacuum tube had a Other Products ................................12 serious drawback - fragility. The Navy was constantly looking for a device with the vacuum tube’s precise ability to control, but with none of its physical limitations. An old device, the magnetic amplifier, became the subject of a new study. Engineers and ABOUT MAGNETICS scientists assigned to this work began to dig deeply into the function the core plays, and particularly what could be done by using newer nickel-iron Magnetics offers the confidence of over fifty years of expertise in the alloys. It was discovered that some alloys would reach saturation with very research, design, manufacture and support of high quality magnetic low magnetizing currents. This started the beginning of a new era for an old materials and components. science - high permeability magnetics. A major supplier of the highest performance materials in the industry Magnetics was established in 1949 when the commercial market for high ® including: MPP, High Flux, Kool Mµ , power ferrites, high permeability ferrites permeability magnetic materials was virtually non-existent and development and strip wound cores, Magnetics’ products set the standard for providing in this field was just taking root. The new simplicity and reliability with which consistent and reliable electrical properties for a comprehensive range of magnetic components could be used opened many doors in the field of core materials and geometries. Magnetics is the best choice for a variety of electronics. Magnetics quickly was positioned as a leader in this field and applications ranging from simple chokes and transformers used in telephone has remained so ever since. equipment to sophisticated devices for aerospace electronics. The first tape cores were used in applications where they were superior to Magnetics backs its products with unsurpassed technical expertise and the fragile vacuum tubes. Tape wound core applications grew rapidly customer service. Magnetics’ Application Engineering staff offers the because these new magnetic components performed far better due to experience necessary to assist the designer from the initial design phase environmental and operational advantages. They contained no parts to wear through prototype approval. The knowledgeable Sales staff is available to or burn out; and the effects of shock, vibration and temperature were small help with all of your customer service needs. This support, combined with a compared to other components. Tape cores also afforded the advantages global presence via a worldwide distribution network, including sales offices of electrical isolation and signal mixing not easily obtainable from other in North America, Asia and Europe, and a Hong Kong distribution center, electric parts. makes Magnetics a premier supplier to the international electronics industry. Some of the magnetic devices in early applications have since been replaced by transistors and integrated circuits; however, a host of new applications and requirements for new core materials have emerged. Magnetic cores are often key parts of complicated electronic circuitry found in highly reliable airborne and space computers, telephone systems, radar installations, jet engine controls, power supplies and nuclear reactors. MAGNETICS – www.mag-inc.com 3 MATERIALS AND APPLICATIONS agnetics offers soft magnetic core materials of saturating and high sensitivity magnetic circuits for all applications. These materials are especially selected and processed to meet exacting magnetic circuit requirements, and are manufactured to tight guaranteed tolerances according to IEEE test procedures or other common industry test Mmethods. SQUARE ORTHONOL SUPERMALLOY (MATERIAL CODE “F”) (MATERIAL CODE “A”) This material is a specially processed 80% nickel-iron alloy. This material, a grain-oriented 50% nickel-iron alloy, is It is manufactured to develop the ultimate in high initial manufactured to meet exacting circuit requirements for very permeability and low losses. Initial permeability ranges from high squareness and high core gain, and is usually used in 40,000 to 100,000 while the coercive force is about 1/3 that saturable reactors, high gain magnetic amplifiers, bistable of Square Permalloy 80. Supermalloy is very useful in ultra- switching devices, and power inverter-converter applications. sensitive transformers, especially pulse transformers, and Other applications such as time delays, flux counters and ultra-sensitive magnetic amplifiers where low loss is transductors demanding extremely square hysteresis loops mandatory. require selection of Square Orthonol. 48 ALLOY (MATERIAL CODE “H”) SQUARE PERMALLOY 80 This material, a 50% nickel-iron alloy, has a round B-H loop (MATERIAL CODE “D”) and exhibits lower saturation flux density, squareness, This material, a non-oriented 80% nickel-iron alloy, is coercive force, and core gain than the Orthonol types. It is manufactured to meet the high squareness, and high core useful in devices requiring lower coercive force such as gain requirements of magnetic preamplifiers and modulators. special transformers, saturable reactors, and proportioning It is especially useful in converters and inverters where high magnetic amplifiers. AC core losses are typically lower than voltage at low power levels are required, but where circuit with Orthonol. losses must be kept to a minimum. Square Permalloy 80 has a saturation flux density approximately 1/2 that of the Orthonol’s, but has coercive force values 1/5 to 1/7 that of MAGNESIL (MATERIAL CODE “K”) the 50% oriented nickel-iron alloys. Core gain for Square This material, a grain-oriented 3% silicon-iron alloy, is Permalloy 80 is higher by approximately 1.7 times the core processed and annealed to develop high squareness and low gain of Orthonol. core loss. It is usually used in high quality toroidal power transformers, current transformers and high power saturable reactors and magnetic amplifiers. It exhibits high saturation flux density with high squareness but has comparatively high coercive force and core loss. With its high Curie temperature, it is quite useful in magnetic devices which are to be exposed to temperatures between 200ºC (392ºF) and 500ºC (932ºF). At higher temperatures, uncased cores should only be used due to case temperature limitations. 4 MAGNETICS – www.mag-inc.com MATERIALS AND APPLICATIONS ROUND PERMALLOY 80 Table 1 TYPICAL PROPERTIES OF MAGNETIC ALLOYS (MATERIAL CODE “R”) PROPERTY 3% Si-Fe 50% Ni-Fe 80% Ni-Fe 50% Co-Fe This material, a non-oriented 80% nickel-iron alloy, is Alloys Alloys Alloys Alloys processed to develop high initial permeability and low (K) (A, H) (R, D, F) (S) coercive force. It has lower squareness and core gain than % Iron 97 50 17 49 the square type, as these characteristics are sacrificed to % Nickel …. 50 79 …. produce the high initial permeability and low coercive force properties. Round Permalloy 80 is especially useful in % Cobalt …. …. …. …. designing highly sensitive input and inter-stage transformers % Silicon 3 …. …. …. 5 where signals are extremely low and DC currents are not % Molybdenum …. …. 4 …. present. It is also useful in current transformers where losses must be kept to a minimum and high accuracy is a % Other …. …. …. 2 V necessity. The initial permeability of this material is usually Density (gms/cm3) 7.65 8.2 8.7 8.2 between 20,000 and 50,000 with coercive force values Melting Point (ºC) 1,475 1,425 1,425 1,480 about 70% that of Square Permalloy 80. Curie Temperature (ºC) 750 500 460 940 SUPERMENDUR (MATERIAL CODE “S”) Specific Heat (Cal./ºCgm) 0.12 0.12 0.118 0.118 This material, available in small quantity by special order, is a Resistivity (µΩ-cm) 50 45 57 26 highly refined 50% cobalt-iron alloy. It is specially processed CTE (x10-6/ºC) 12 5.8 12.9 9.9 and annealed to develop high squareness