SELF

80

S.B. Karavashkin and O.N. Karavashkina

4. Description of the first experimental set

We used a standard ferromagnetic E-core which had the width of central leg 20 mm, of side legs 10 mm and the thickness of the package 53 mm. The size of core was 8080 mm . The primary winding was reeled up on the side leg of core which had the size 1053  mm  and 140 turns of wire with diameter 0,42 mm. The winding was solid, in two layers.

The secondary loop had the size 220240 mm  and contained 43 turns of wire with the diameter 0,11 mm. Its plane was placed co-axially with the turns of primary winding. The nearer side was places exactly at the middle of primary winding and height of core, this provided the device symmetrical in the core height.

To measure the emfs induced in the secondary loop, its leads were connected to the input of two-ray oscillograph  C1- 77  , and the primary winding was connected to the generator of low-frequency signals   3-56/1 and to the first input of this oscillograph, in accordance with Fig. 9. The oscillograph was synchronised by the voltage phase at the primary winding.

Fig. 9. Experimental set to study the rate of induction emf diminution with the distance from outer side of core exciting the inhomogeneous magnetic field

Thus, the voltage at the primary winding was controlled at 14 V span on all the frequency range. The data were read out from the oscillograph. For better accuracy of measurement, the mean line of both rays was shifted down the screen of oscillograph. With it the amplitude value of time-variable emf induced in the secondary loop was measured.