Toroidal magnetic cores type DC

Magnetic cores GAMMAMET®

Magnetic properties of toroidal encapsulated magnetic cores from amorphous and nanocrystalline alloys

Magnetic core Magnetic induction of saturation, T Initial relative magnetic permeability Maximal relative magnetic permeability Squareness factor of loop of a hysteresis Coercive force, А/m Specific core losses P0.2/20W/kg Specific core losses P0.05/100W/kg Curie temperature, °C Density, kg/m3 Saturation magnetostriction
GM 11DC 0,32 50000 150000 0,5 0,4 35 35 150 5400 <0,2×10-6
GM 14DC 0,8 20000 50000 0,4 2 70 60 600 5200 1,5×10-6
GM 32DC 0,8 7000 200000 0,88 2 130 160 610 5200 <1×10-6
GM 33DC 0,4 3000 600000 0,9 0,5 100 130 260 5400 <0,2×10-6
GM 35DC 0,7 200 150000 0,92 2 560 900 500 5400 <0,2×10-6
GM 40ВDC 1,0 3000 7000 0,15 8 150 120 420 5100 25×10-6
GM 42DC 0,8 20000 25000 0,1 2 80 80 610 5200 <1×10-6
GM 43DC 0,4 35000 40000 0,05 0,5 75 70 260 5400 <0,2×10-6
GM 45DC 0,7 1200 1350 <0,01 2 220 250 500 5400 <0,2×10-6
GM 54DC 0,8 (30-1000) (31-1100) <0,01 3 (100-510) (80-390) 600 5200 1,5×10-6

The properties of a magnetic material are specified in the table above . It is necessary to consider factor of filling magnetic core by magnetic material in electrotechnical calculations. The nominal factor of filling for an amorphous ribbon - 0,7

In the table are specified the properties carried to unit of geometrical section or unit of magnetic core volume. Conditionally magnetic core is filled by a certain effective magnetic material with tabulared magnetic properties. Therefore in electrotechnical calculations the factor of magnetic core filling by a magnetic material is accepted equal 1.

Marks of magnetic core type DC

Magnetic cores of DC type are impregnated by inorganic glue which gives to them a rigid construct. Additional rigidity is given by a cover atop of magnetic core. The covering can be made of different materials depending on the size magnetic core or using temperatures. The standard covering consists of a polymeric cover by thickness from 0,4 up to 1,2 mm which simultaneously carries out a role of insulating cover. The covering can be made also from glass insulating ribbon or from enamel

Cross-section section of a type DC magnetic core:

  1. Ribbon magnetic core,
  2. Cover.

Symbol structure of magnetic core DC conditional mark. The first symbol of conditional mark is the index of group corresponding to the basic requirement to magnetic properties

  1. High initial magnetic permeability,
  2. Low specific core losses,
  3. High squareness ratio of magnetic hysteresis loop,
  4. Low squareness ratio of magnetic hysteresis loop,
  5. High reserved magnetic energy.

The second symbol is the index of a magnetic core alloy:

0 - GM 440, 1 - GM 501, 2 - GM 412, 4 - GM 414, 5 - GM 515, 7 - electrical steel 0.08 mm 9 - electrical steel 0.27 - 0.35 mm.

The third symbol designates a covering over the core. The fourth symbol designates a impregnation by glue.

Structure of the magnetic core К conditional mark.

Magnetic core DC can have conditional marks on a lateral surface of core according to their class

Relative magnetic permeability GM 54DC GM 40DC GM 14DC GM 11DC
30 •••      
60 ••      
90 •      
140 |      
250 ||      
350 ||| √√√    
500 v √√    
700 vv √    
1000 Ο +    
1500   ++    
2000   +++    
1 class     1 1•
2 class     2 2•
3 class     3 3•

Magnetic cores GM 45DC, GM 43DC, GM 42DC, GM 35DC, GM 33DC, GM 32DC have conditional marks in the form of symbols accordingly 45, 43, 42, 35, 33, 32.

The various sizes of cores are available with outer diameter up to 600 mm, but magnetic cores GM 45DC, GM 43DC, GM 42DC - no more than 140 mm.

List of agreed specifications

  • ТУ 1261-031-12287107-2008 Composition magnetic cores GAMMAMET