High Performance Power Supplies
  • 4 MOSAIC System
    Modular CIME HPPS
  • 5 High current rectifier
    7V – 6500A
  • 2 RF Final Amplifier
    Anode Power Supply
  • 1 Transformers
  • 3 Cyclotron Power Supply
    Driver Amplifier

Historically produced by JEMA since its creation in 1937, coil-based products are still an essential part of our catalogue. The transformers and resistors made in our workshops are of course available to our clients but are also incorporated daily into out high performance power supplies.

Keeping full control of both the design and production of these essential components ensures the highest degree of performance and reliability in our power supplies destined for the most demanding uses such as proton therapy (treatment of cancer using particle beams) or high energy physics research. Of course, all of our clients benefit from this build quality.

Transformers - Resistances

Air cooled dry Transformers:

Because we primarily produce made-to-measure transformers, JEMA is able to adapt production to your needs, within ample limits, for one-off items and small and medium-sized series.
Our offer covers all production of single-phase and three phase transformers, autotransformers and inductors in a range stretching from a few Volt-Amperes (VA) to 1000 kVA. Our products are available in different insulation classes and different protection indexes (IP) up to IP55.

The table below gives a quick overview of our standard range:

1 phase TFO 1 column
100VA – 5kVA

Download .pdf

1 phase TFO 2 columns
6.3kVA – 100kVA

Download .pdf

3phase TFO 3 columns
630VA – 640kVA

Download .pdf


Special products:

JEMA's research department is available for consultation or production of static coil-based devices for your particular uses. Production may be carried out according to different standards, in different insulation classes and for all types of coupling for multi-phase productions.


  • Adaptors for both primary and secondary, electrostatic screen, temperature gauge. Y/Y, Δ/Δ, Y/Δ. Δ/Y, Zig-Zag (for secondary networks susceptible to pronounced imbalances), and Scott (for a perfect balance of two equal single-phase charges on the three phases of a three-phase network) couplings.
  • "THREE-SINGLE" products (Three-phase primary coil winding – Single-phase secondary coil winding)
  • Six-phase and Twelve-phase Transformers.
  • Specific couplings for rectifier fittings (ex: Double star with interphase...)
  • Low tension products for very high currents (up to 150kA)
  • Product with limited ignition current
  • Possibility of forced air cooling.










Our range of JEMA resistors is made up of the following types:   




AERA Resistors

AERA type fixed resistors were designed especially for medium and strong dissipations such as charge banks, motor ignition, etc.

AERA model resistors are available in various implementations:


  • Frame only or with fastening flanges

  • Grouped - up to 6 items connected in series or parallel

  • With or without protection



Slide Resistors - Rheostats

Slide resistors or rheostats are intended for continuous regulation of electric circuits. A coil of pure constantan wire is wound in contiguous circles around a tube of refractive material with a set profile and a size suited to the power to be dissipated. Where necessary, several rectilinear items may be grouped on a single frame. The regulation of the rheostat is performed through a flexible slider ensuring constant contact with the coil. This is controlled either directly through an insulated button or through a screw system fitted with a crank handle or wheel. Connections are made using insulated (up to 40A) or non-insulated terminals (above 40A). For special applications up to 5.2A the terminals may be of a universal type, thus allowing for connection by wire, terminal or plug.

Where necessary, the coil may be made with a progressive section of constantan. The current being inversely proportional to the resistance entered, this allows circuits to be regulated for a constant impedance value. It is also possible to make coils without inductors or capacity through a crossed double coil.

We make any special out-of-catalogue products on request.




Fixed coil-based resistors

The fixed coil-based resistors are made up of a tube in refractive material with a coil of pure constantan film with tightening collars on each end. All of the resistors are delivered with a regulating collar, with the exception of those with a high ohmic value or weak obstruction. With their varied uses, these resistors (Model T) are particularly useful for industrial applications such as charging accumulators, motors, dynamos, alternators and resistors causing a drop in tension. Model T resistors are usually supplied in various implementations:

  • Single tube with regulating collar

  • With or without fastening flanges

  • With or without protection

  • With or without connection terminals


Connections are made by means of 2 brazed terminals on the coil wire. All types are supplied with a regulating collar, which is reinforced for certain applications requiring increased insulation and working security (Model TA).