High Frequency Surgical Instruments

Stimulation Currrent Therapy

X-Ray Units

Inductive components and EMC filters for Medical systems

Inductive components and EMC filters forMedical systems

Alongside the focal areas of renewable energies, industrial applications and telecommunication systems, the market segment of medical technology is of strategic significance for PRAX.

PRAX develops and produces inductive components and EMC filters for high-frequency surgical instruments, stimulation current therapy and X-ray units:

Pulse Transformers

Used to isolate high voltage from control circuits, its function helps to shoot the IGBTs in switch mode power supplies. PRAX is able to design and manufacture pulse transformers for frequencies up to 1MHz and isolations up to 10kV. Leakage inductance and interwinding capacitance can be controlled using optimized winding techniques, assuring reduction of spikes and best possible transmission of voltage-time area of pulse waveform.

Current and voltage sensors

Current and voltage sensors are used to monitor power. By using different magnetic materials (FeSi, NiFe, Nanocristalline, Ferrite) depending on measuring frequency range, PRAX optimizes sensors accuracy. Special isolated wires and potting systems assure maximum isolation and voltage ratings. Current measurements sensors go up to 1000 Amps and frequency measuring range from 50Hz up to 1 MHz.

Transformers and inductors

Transformer and inductors for medical power supplies systems (switched-mode power supply). PRAX develops customized power transformers for switched mode power supplies in all the usual switching topologies, such as: 

  • Flyback converters
  • Forward converters
  • Push-pull converters
  • Half-Bridge
  • Full-Bridge
  • Resonant converters
  • Quasi resonance converters
  • Current doublers
  • Cuk converters

In order to obtain the desired technical characteristics, a wide variety of core materials, conductors and designs are used.

Core materials used:

  • Soft ferrites
  • Amorphous core materials
  • Nanocrystalline core materials
  • Tape-wound SiFe cores

Conductors used:

  • Solid copper wires with round and rectangular shapes
  • Litz wires (Cu)
  • Copper foil strips
  • Tube materials for direct water cooling (Cu, Al)


  • Bobbin core windings
  • Toroidal core windings

Lead frame windings (planar transformers) 

PRAX develops and manufactures customized chokes for all applications like storage chokes, resonant choke, pulse choke, PFC choke and non-linear choke (step-gap choke)

In order to achieve the required technical characteristics, a wide range of core materials, conductors and other materials are used, regardless of the manufacturer and the brand.

The core materials normally used are:

  • Nanocrystalline cores
  • Soft ferrite
  • Iron powder
  • MPP
  • Sendust
  • High Flux
  • Si-Fe
  • Nickel-iron
  • Amorphouscores
  • Nanocrystalline cores

EMC Filters

PRAX offers EMC filters for Medical Systems considering safety and reliability are key factors for high-end medical systems (X-ray, MRI, lasers).

Such filters have been designed to meet medical standards as EN-60601. Topology and internal components are chosen to optimize attenuation despite leakage current is limited by safety regulations.

Most of these filters come with IEC connector in metal housing for compact solution in final equipment for easier assembly.