Nanocrystalline cores (MagAmp) with a rectangular hysteresis loop

MSSN series

Toroidal saturation magnetic circuits of the MSSN series, made of a thin (18–20 µm) iron-based nanocrystalline ribbon AMAG 200, represent a new class of products with unique properties.

They complement the long-standing cobalt-based amorphous alloy (MSSA) saturation cores traditionally used for high-performance multi-channel power supplies based on magnetic amplifiers.

Through careful selection of the material composition and thermomagnetic treatment modes, it was possible to achieve excellent soft magnetic properties at high (up to 300 kHz) operating frequencies (coercive force and losses approach the characteristics of amorphous cobalt-based alloys) in combination with a very high saturation induction - 1.2 T, typical for iron-based alloys.

In addition, the new soft magnetic material with a rectangular hysteresis loop has a very high squareness coefficient, higher thermal stability than amorphous materials, and an increased operating temperature (up to + 120 ° C).

The specific properties of the new material contribute to the reliability of magnetic amplifier cores, improving characteristics, and minimizing dimensions.

 

 

 

Dimensions and main characteristics

MSSN series

Core name ​​

Dimensions 1) in container
(without container)
(D-d-H)
(mm)

 Leff 2)
(mm)		 Aeff 3)
(mm2)		 Veff 4)
(mm3)		 Wa 5)
(mm2)		 m 6)
(g)		 2Φm 7)
(μVb)
± 15%

 

In a plastic container
MSSN-10B-L

11,9 - 5,8 - 6,3

(10,0 - 6,8 - 4,5)

 26.37 5.18 136.6 26 1.00 13.5
MSSN-11S-L

14,0 - 6,6 - 6,3

(11,0 - 8,0 - 4,5)

 29.83 4.86 145.0 34 1.06 12.6
MSSN-13B-L

14,7 - 7,8 - 5,1

(12,8 - 9,5 - 3,2)

 35.01 3.80 133.0 49 0.98 9.9
MSSN-15S-L

16,9 - 8,6 - 6,5

(15,0 - 10,0 - 4,5)

 39.25 8.10 317.9 59 2.32 21.1
MSSN-18S-L

19,8 - 10,4 - 6,4

(17,4 - 12,0 - 4,5)

 46.16 8.75 403.9 85 2.95 22.7

Note:

  • 1) Nominal dimensions of the finished core in the container. Ext. dia. - Int. dia. - Height.
  • 2) Nominal values ​​of the magnetic center line length.
  • 3) Nominal values ​​of effective cross-sectional area.
  • 4) Nominal values ​​of effective volume.
  • 5) Nominal values ​​of window area.
  • 6) Nominal values ​​of the mass of the core without container.
  • 7) Full (double) flux at 100 kHz, 80 A/m, and +25 °C.
    * Squareness coefficient, Br/Bm is more than 97% in 100 kHz mode, 80 A/m and +25 °С.
    * Coercive force, Hc below 35 A/m (typical value 25 A/m) at 100 kHz, 80 A/m and +25 °C.

 

 

​ Application Information (MSSN series)

​ Program for calculating inductors of magnetic amplifiers

Application

  • Magnetic Amplifiers for Switch Mode Power Supplies
  • Magnetic amplifiers for DC / DC converters
  • Computer power supplies
  • Pulse transformers
  • Transformers for self-excited inverters
  • Other saturation devices

 

Advantages

  • High squareness (reducing the dead time of the magnetic amplifier choke and improving the regulation mode)
  • Very high saturation induction (downsizing of chokes)
  • Low coercive force (reduction of reverse recovery current and overheating of regulator components)
  • Low losses in the magnetic circuit (increase in operating frequencies)
  • Increased operating temperature limit: up to 120 °C (high frequency operation)

 

Additional parameters and characteristics

Specific losses, Pc (f, ΔB)
Temperature dependence of Br / Bm
Frequency dependence of Hc
Temperature dependence of Br / Bm
Temperature dependence of Bs

The main characteristics of the material used

  • Material AMAG 200
  • Amplitude of induction, Bm (25°C) 1,20 T
  • Amplitude of induction, Bm (90°C) 1,15 T
  • Squareness coefficient Br/Bm (at 100 kHz, 80 A/m), not less than 0.97
  • Squareness coefficient Br/Bm (at 1 kHz, 80 A/m), not less than 0.93
  • Specific power losses Psp (at 50 kHz, 0.4 T), not more than 130 W/kg
  • Curie temperature, Тс 570°C
  • Operating temperature range from –60 °C to + 120 °C
  • Saturation magnetostriction (at 25 °C) less 2,0 × 10-6

Design

The twisted tape magnetic core is placed in a rigid protective container made of glass-filled polyamide and mechanically fixed with silicone sealant. The container has rounded edges and is designed for direct wrapping with thick wire. The container provides reliable mechanical protection of the nanocrystalline material and the preservation of its properties.

Recording example

MSSN-10B-L, where:

  • MS - MSTATOR;
  • S - application (saturable = saturation core);
  • N - material designation;
  • 10 - outer diameter, mm;
  • B - sectional designation;
  • L - type of heat treatment (in the longitudinal magnetic field)