SU398902A1 - DEVICE FOR REMOVING THE MAGNETIZATION CHARACTERISTICS - Google Patents

Description

one

The known devices for taking magnetization characteristics, containing a source of direct current, a winding on the sample, a key and a recording instrument, are complex and they cannot automatically record the characteristics due to the need to take measurements discretely but with a deviation of the arrow of the galvanometer. .

To simplify and automate the recording of the magnetization characteristic in the proposed device, the sample winding is connected to the source of a constant current through two opposite zener diodes connected.

FIG. 1 shows a diagram of the described device; in fig. 2 - curves of the current change in the winding of the test sample over time.

The device consists of a source / residual current, a key 2, which are inversely connected in parallel to the winding 3 of two zener diodes 4, a shunt 5 connected in series with the winding, and an oscilloscope 6.

When the key is turned on, as a result of a transient process, the current in the value of the winding changes (Fig. 2). Since the voltage on the winding is stabilized, the winding note value changes at a constant rate:

- and dt

u dB ,, .ui rz: and with

at B-

(,

W-S

where H is the winding flux estimate, B is the induction, w is the number of turns of the winding, 5 is the cross section of the core, UCT is the stabilization voltage, / is the time.

Thus, induction in the core varies in proportion to time with the coefficient of nonnorrationality:

Ucr

20

wS

The field strength varies in proportion to the winding current with a ratio proportional to:

Kn

wed

where / av is the average length of the magnetic field line. When the key is turned on, the oscilloscope records the curve a (Fig. 2) of the change in current (t), which in scale is a characteristic of magnetization. When the key is turned off, the current drops along the curve b, which is the scale of the back of the particular cycle of the magnetization reversal. If the curve b is mirrored and transferred parallel to the curve b, then one can construct a half symmetric cycle. The second half of the cycle is constructed graphically, based on its symmetry, or removed when the current source changes polarity with a key. Subject of the invention A device for characterizing magnetising, containing a source of direct current, a winding on a sample, used for magnetization and measurement, a key and a recording device, characterized in that, in order to improve and automate the recording of the magnetization characteristic, it is equipped with two opposite ones. zener diodes introduced into the measuring circuit between the outputs of the sample winding and the DC source.

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