Toroidal Magnetic Circuit
In order to create a closed loop the Company developed production of its own toroidal magnetic circuits (core rings). Available equipment makes it possible to work with any kind of electric steel with thickness of 0.08 to 0.5 mm.
URS-1 Steel cutting machine provides the following strip thickness, mm: 8, 14, 16, 20, 22, 23, 25, 30, 32, 35, 40, 45, 50, 55, 70, 90.
This strip thickness range, availability of finished arbors and maximum outer diameter of mechanical winding equal to 380 mm makes it possible to optimize mass-dimensions of magnetic circuits (cores) for specific item. Besides, coiled cores undergo turning machining for chamfering of internal and outer bevels. This stage allows:
- to decrease bending stress of enameled wire during magnetic circuit coiling, that in turn reduces the risk of winding damage (it is especially topical during accurate mechanical wire laying with big tension);
- to decrease coil turn length and consequently coils wire consumption;
- to minimize barrel shape of finished transformer.
Heat treatment of magnetic circuits is performed in shaft furnaces. Shaft furnaces in comparison with tunnel furnaces provide more controlled annealing process and more stable magnetic permeability indicators of finished products. Minimal induction of annealed cores is 15500 Gs.
Example of reference designation: OL 40/64-25, where inner diameter (d) = 40 mm, outer diameter (D) = 64 mm, height (h) = 25 mm. A range of standard dimension types of magnetic circuits made of electric steel, more often used in manufacturing, is given below.
Magnetic circuit designation | Design weight, kg | Power-to-size ratio, W |
ÎË 22/34-20 | 0.079 | 6.5 |
ÎË 26/40-20 | 0.109 | 10.5 |
ÎË 26/40-25 | 0.136 | 13.2 |
ÎË 26/44-20 | 0.148 | 13.6 |
ÎË 30/52-20 | 0.212 | 22 |
ÎË 35/55-20 | 0.212 | 27 |
ÎË 35/64-20 | 0.338 | 39 |
ÎË 40/65-20 | 0.309 | 44 |
ÎË 40/64-25 | 0.367 | 54 |
ÎË 40/67-25 | 0.425 | 60 |
ÎË 45/70-25 | 0.423 | 70 |
ÎË 45/75-25 | 0.530 | 84 |
ÎË 50/80-25 | 0.574 | 105 |
ÎË 50/80-30 | 0.689 | 125 |
ÎË 54/96-32 | 1.186 | 218 |
ÎË 65/105-30 | 1.201 | 283 |
ÎË 65/105-40 | 1.601 | 375 |
ÎË 70/120-40 | 2.236 | 545 |
ÎË 80/130-40 | 2.472 | 715 |
ÎË 90/175-20 | 2.651 | 760 |
ÎË 80/140-40 | 3.107 | 850 |
ÎË 95/155-40 | 3.531 | 1207 |
ÎË 100/180-40 | 5.275 | 1785 |
ÎË 100/180-55 | 7.250 | 2450 |
ÎË 100/190-65 | 9.985 | 3260 |
ÎË 115/208-55 | 9.725 | 3770 |
* - overall dimensions may be changed optionally.
We also perform winding of magnetic circuits with an iron-nickel alloy (permalloy) strip.