Sintermetalle Prometheus GmbH & Co KG (SMP), a manufacturer of soft-magnetic materials and inductive components headquartered in Graben-Neudorf, Germany, now offers maintenance-free chokes for medical applications. These inductive components are, amongst other applications, used in Magnetic Resonance Imaging (MRI) and Computed Tomography (CT). Designed as filter or mains chokes, they are compact, low-loss and energy efficient, as well as being exceptionally quiet in operation – all essential qualities for medical technology applications.
In MRI scanners, the components are installed in the ‘gradient amplifiers’, which control the gradient coils that encode the resonance signals for 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, enable components to 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.
The three-dimensional isotropy of the materials enables compact, lightweight structures, because the magnetic circuits are minimised. This also lowers the magnetic field strength, and the quantity of winding material used can, thus, 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 also applicable to 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.