New Industry Products

Chokes from SMP for Medical Applications Offer Low Loss and Low Noise

June 01, 2021 by Hailey Stewart

This article highlights SMP chokes for medical technology applications in which these inductive components are used in Magnetic Resonance Imaging (MRI) or Computed Tomography (CT).

Graben-Neudorf, Germany. SMP Sintermetalle Prometheus GmbH & Co KG (SMP), German manufacturer of soft-magnetic materials and inductive components, offers chokes for medical technology applications. These inductive components are used in Magnetic Resonance Imaging (MRI) or Computed Tomography (CT), for example. Designed as filter or mains chokes they are not only compact, low-loss and energy efficient but also exceptionally quiet in operation – essential qualities for demanding medical technology applications.


Image courtesy of SMP
Image courtesy of SMP


In MRI scanners, the components are installed in the gradient amplifiers, which supply output voltages and currents and control the gradient coils that encode the resonance signals for subsequent image reconstruction. The filter and mains chokes are designed to ensure a clean sinusoidal waveform and low-loss feedback of the unused energy.

Special magnetostriction-free materials, which SMP develops and produces according to individual customer specifications, ensure that components run very quietly. The powder composite materials feature low eddy current and magnetic reversal losses. The components are noted for their low loss balances and optimal EMC properties. They are also maintenance-free. The three-dimensional isotropy of the materials enables compact, lightweight structures, because the magnetic circuits are minimized. This also lowers the magnetic field strength, and the quantity of winding material used can be significantly reduced. The materials have a high saturation induction of up to 2 Tesla. The oscillation behaviour of the choke can be adjusted specifically by using certain materials or appropriate, magnetically coupled designs with multiple coils.

SMP components are designed for currents of up to 3000 A and for frequencies up to the gigaHertz range. The components can be produced with dimensions from 19 mm to 300 mm and weights from 0.05 kg to 130 kg. All components are RoHS and REACH compliant and CE and EAC certified, and the materials used are UL-listed.

Besides medical technology, 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, in renewable energies and power supply, and in the aerospace industry.


About SMP

SMP Sintermetalle Prometheus GmbH & Co KG was founded in 1982 by Dr.-Ing. Vasilios Gemenetzis. In Graben-Neudorf (Baden) near Karlsruhe SMP produces inductive components, filter systems, cores and molded parts on the basis of soft magnetic materials. The components are used in different power electronic applications. SMP produces nearly 100 % of the products customized. The products are sold with an export rate of over 50 % worldwide. Over the years SMP has become one of the most important suppliers for inductive components with soft magnetic materials in industrial applications on the world market. The change of generations is already done. Both sons of the company's founder are involved in the family business for a couple of years now and completed their studies in electrical engineering and information technology with a master's degree at the Karlsruhe Institute of Technology (KIT). Two production locations in Germany and Austria with seven isolated halls regarding fire safety with an area of more than 14.000 m² secure reliable supply and production.