Iskra is one of the major producers of various types of strip wound transformer cores made of oriented silicon iron steel strip. 

1. Energy sector
Electrotechnical
components
Secutity, supply &
managementTelecommunicationsEfficient installations Traffic Services
Programme of wound cores
Energy sector
Electrotechnical
components
Efficient
installations Traffic Telecommunications
Facility
management
Services

2. Programme of wound cores
M103-27P, thickness 0.27 mm;
M089-27N, thickness 0.27 mm;
27JGSD090, thickness 0.27 mm;
23JGSD080, thickness 0.23 mm;
Trafoperm N2, thickness 0.1 mm.
Strip width: 10, 15, 16, 18, 19, 20, 21, 22,
25, 30, 32, 40, 42, 44, 50, 54, 55, 65, 70,
90, 105 mm
Wound cores are winded of different GOESS:
Frequency: 50, 60, 400, 1.000 Hz

3. 3
Materials designation overview
Abreviations DIN46400
Old
designation
New
designation
EN10107
Power loss
Thickness,
mm
Power loss
at
1,5 T
Power loss
at
1,7 T
M0 - 27M0H M103-27P low 0,27 - 1,03
M0 - 30M0H M105-30P low 0,3 - 1,05
M1 VM111-30P 30M1H M111-30P low 0,3 - 1,11
M2 VM117-30P 30M2H M117-30P low 0,3 -- 1,17
- - - M120-23S lower 0,23 0,77 1,2
M3 VM130-27S 27M3 M130-27S lower 0,27 0,85 1,3
M3 - 23M3 M080-23N normal 0,23 0,8 1,27
M4 VM89-27N 27M4 M089-27N normal 0,27 0,89 1,4
M5 VM97-30N 30M5 M097-30N normal 0,3 0,97 1,5
M6 VM111-35N 35M6 M111-35N normal 0,35 1,11 1,65
- VM140-30S - M140-30S lower 0,3 0,92 1,4
M7 - 30M7 M175-50N normal 0,5 1,75 -
- - GT100 - - 0,1 1,1 -
27JGSD090 M90-27P low 0,27 0,90
23JGSD080 M80-27P Very low 0,23 0,80
Designation of GOESS materials

4. 4
BH Curves
Magnetisation of feromagnetic substances Magnetisation curves of some materials
Electromagnetic curves

5. 5
Electromagnetic properties
Relative permeabilits is depend of temperature and
frequency
Hysteresis loop of feromagnetic material
Permeability and Hysteresis loop

6. Applicaiions
 Insulating transformers up to 13kVA
 Auto transformers
 Variable auto transformers
 Audio transformers
 Toroidal transformers
6
Standard cores: Customer made cores:
 Instrument transformers (Voltage and
Current transformers)
 SMPS transformers (welding devices
etc.)
 Special gapped cores
 Chokes
Beside wound cores made of different electrical steel, we can offer also:
 Coilformers
 Clamps
 Holders
 Rubberwasher for toroidal transformers and choke
 Tinned round plate for toroidal transformers and chokes

7. 7
Cores overview
Toroidal cores for CT
Toroidal and E cores Ovalcores

8. 8
Cores overview
Rectangular cut cores for CT
Toroidal cut cores and housing for CT
C cores Rectangular and toroidal cut cores

9. 9
Drawing, Insulations and Test points
Drawing of rectangular cut core for CT Test points for MDK 1000A
Bmax. (T) Heff (A/m)
0,1 ≤ 7,5
0,9 ≤ 45
1,6 ≤ 76
Insulations::
 Mylar foil, width 5 or 10 mm, d=50µm
 Resicoat, UL, epoxy, d ~ 500 µm
 Epoxy color, rost protection
 Housing
Data overview

10. Catalogues
Most of our cores are made according to customer design
Catalogue for standard wound cores is available on our
web site in PDF form

11. Contacts
Thank you!
Iskra, d.d.
Headquarters:
Stegne 21
SI-1000 Ljubljana
Slovenia
Phone: +386 1 513 10 00
Fax: +386 1 511 15 32
E-mail: iskra@iskra.eu
www.iskra.eu