Magnetically coupled inductive components save weight & cost

Magnetically coupled components boast several advantages over components that are not magnetically coupled: they are less expensive, they are made using less material, so they are more compact and weigh less, and their loss balances are lower than those of non-magnetically coupled components (eco-design). Faster clock frequencies are also possible. The quality factor is set without exposing the choke to any thermal load, and EMC considerations are reduced. The magnetising and leakage inductances can be specifically set by adjusting the magnetic coupling. This is done by varying the geometries of the injection moulded parts and using different coil types, such as separately wound coils, bifilar coils or superimposed wound coils.

The range of magnetically coupled components is designed for currents up to 2000A and frequencies up to 500kHz, which can be increased to 2MHz in special applications. SMP uses powder composite materials that have been developed and manufactured entirely in-house and feature lower eddy current and magnetic reversal losses. The three-dimensional isotropy of the materials results in compact, lightweight structures, because the magnetic circuits are minimised. This also lowers the magnetic field strength, and the quantity of winding material used can be significantly reduced. Special magnetorestriction-free materials ensure that components run very quietly. These materials, which are developed and produced according to individual customer specifications, have a high saturation induction, up to 2 Tesla. Oscillation behaviour of the choke can be adjusted specifically by using certain materials or appropriate, magnetically coupled constructions with multiple coils.

Depending on application, the magnetically coupled components from SMP are constructed for use as transducers, medium-frequency transformers, flux-compensating chokes or controlling chokes. Controlling chokes are produced by adding another coil in the role of transformer. They are implemented, for example, for control signals, for monitoring choke saturation, to measure current, to adjust the quality factor with thermal relief of the choke, also with possible energy recovery, and for setting a specific induction by premagnetising the magnetic material.

Magnetically coupled components are used in industrial applications in power electronics, automation and signal processing, in drive units for railway engineering, electromobility, maritime and medical engineering, for renewable energies as well as for energy supply, and in the aerospace industry.

The components can be manufactured with dimensions ranging from 19 to 300mm, weighing from 0.05 to 130kg, and up to temperature class H (up to +180°C). Protection classes up to IP66 are available according to the intended application. All components are RoHS and REACH-compliant, the materials used are UL listed. SMP has its own UL-approved insulation system and in-house capability to issue UL certification up to 1000A. For currents higher than 1000A, certification is carried out externally.

The German business develops and manufactures the materials needed according to individual customer specifications in-house. SMP has also expanded its production and development facility to include an injection moulding department, so that it can design and manufacture customised insulation systems. Almost 100% of its products are custom-made for specific customers. Consequently, SMP can offer depth in manufacturing, starting with its selection of raw materials and continuing through the production of powder composite materials to the finished end product. Over 50% of its goods are exported to destinations all over the world.