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Energy-efficient chokes with compact design and IP66 protection rating

Published: 31 October 2018 - Sarah Mead

SMP Sintermetalle Prometheus GmbH & Co KG (SMP) offers chokes with a protective paint coating according to IP66 which protects them from water and dust. The components are used to choke the current in inverters that are exposed to harsh ambient conditions, including rail vehicles or oil rig applications. The chokes are to be exhibited at Electronica 2018 in Munich and at SPS IPC Drives 2018 in Nuremberg.

Energy-saving and compact

The IP66 protection rating enables the chokes to be mounted outside the inverters. The advantage of this kind of mounting is that the heat generated by the choke is created outside the inverter, not inside it. A lower temperature inside the inverter eliminates the need to dissipate the heat using fans, which in turn saves energy. Another advantage of mounting them on the outside is that the inverter can be designed significantly smaller. External mounting is beneficial for the choke itself, because it can be adapted to the expected ambient temperature in its operating environment. For example, whereas temperatures inside the inverters in railway applications can reach 70 to 80 °C, the temperature outside inverters in underfloor-mounted electronics is not expected to exceed about 40°C.

Even on open water oil rigs

SMP has developed chokes with a protective paint coating for mounting outside the inverter even in applications on open water oil rigs, where exposure to intense sunlight, seawater, rain and chemical gases is expected. To simplify mounting outside the inverters, SMP also provides the chokes with special mounting fixtures. The choke and the mounting plate are both located outside the device, the connecting wires pass into the interior through a sealed opening.

From 0.05g to 130kg

SMP specialises in customer-specific development and manufacture of inductive components and filter systems. The component portfolio is designed for currents of up to 2000 A, up to 3000 A for special applications, and for frequencies up to the gigaHertz range. The materials have been developed and manufactured by SMP specifically for this purpose and have high saturation induction of up to 2 Tesla. The individual components can be produced with dimensions from 19 mm to 300 mm and weights from 0.05 kg to 130 kg. The temperature class H (up to 180 °C) insulation system is UL certified. HL classes according to EN 45545 can be specified according to requirements.

Drive applications and more

The filter systems and inductive components are used in industrial applications in the power electronics, automation and signal processing sectors, in drive applications for railway engineering, electromobility and marine engineering among others, in medical technology, renewable energies and power supply and in the aerospace industry.

In-house developed powder composite materials

SMP’s products are manufactured according to individual customer specifications and marketed worldwide with an export quota of over 50 percent. The company was founded in 1982 by material science expert Dr.-Ing. Vasilios Gemenetzis for the purpose of manufacturing sintered metals in a process he had developed himself. Since 1994, SMP has shifted its focus to manufacturing electrical components. Material science remains an essential factor in the development of ultra-low loss inductive components: The powder composite materials used for the components are specially developed and produced for each application according to customer‘s specifications. In the course of the years, the family-owned company has become one of the key global suppliers of magnetically soft materials for industrial applications. In order to be able to control the full production cycle, in 2008 a further factory was founded for the proprietary development and manufacture of powder composite materials. In 2011, SMP expanded its production capabilities with an injection moulding facility, so that the company itself can now develop and manufacture coil carriers and insulation systems for the components. With the addition of a new EMC laboratory, SMP is now able to carry out measurements of both conducted and radiated emissions.

Trade shows

In November 2018, SMP exhibits at the following trade shows: at Electronica 2018, from 13 to 16 November 2018, in Munich, Germany (Hall B6 Stand 351), and at SPS IPC Drives 2018, from 27 to 29 November 2018, in Nuremberg, Germany (Hall 3 Stand 360). For more details, please visit

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