RU1803893C - Device for measuring magnetic characteristics of devices - Google Patents

Abstract

Usage: for magnetic measurements. SUMMARY OF THE INVENTION: in the process of magnetization reversal of a test sample according to the equality of residual induction and the product of magnetic constant vacuum and residual magnetization, the device fixes the moment the internal field of the sample vanishes. At this moment, the demagnetizing factor of the sample is stored, after which the recording device automatically fixes the dependence of the magnetization of the sample material on the applied field. 2 ill. ё

Description

I The invention relates to magnetic measurements and can be used to control the magnetic characteristics of magnetic materials on samples in an open magnetic circuit.

The aim of the invention is to increase the productivity of the test process by automating the process of setting the gear ratio of the link with an adjustable gear ratio.

As can be seen from expressions (1) and (2), the remagnetizing field strength is not equal to the intrinsic demagnetizing field at the moment when the magnetic field strength inside the test sample is equal to zero, i.e. at the point corresponding to the residual magnetization of the magnetic material Mg, from which the sample is made. For fixation during magnetization reversal of the test sample

At this point, we can use the fact that at the point of residual magnetization of the hysteresis loop of the magnetic material, the equality is observed:

Vg // about Mg,

where Vg is the value of the residual induction of the characteristic B (H) of the magnetic material. In this regard, the aforementioned goal is achieved in that: a device for measuring the magnetic characteristics of materials, comprising a magnetizing device, to the output of which a magnetizing system and an external magnetic field measuring transducer are connected in series, a magnetization measuring transducer of the test sample, consisting of a measuring and compensating windings

00 О СО 00 Ю

with

an integrator connected to the output of the magnetization measuring transducer, a recording device, an amplifier connected to the output of the voltage measuring transducer, an adder, the first input of which is connected to the amplifier output, and an output to the first input of the recording device, the second input of which is connected to the integrator output, the link with adjustable transmission coefficient, the output of which is connected to the second input of the adder, and the first input to the output of the integrator additionally introduced a divider memory device yours, the second integrator, the comparison circuit, the link with a constant gear ratio, the input of the second integrator connected to the output of the measuring winding, the first input of the divider connected to the output of the amplifier, and the second to the output of the first integrator, the input of the link with a constant gear ratio the output of the second integrator, and the output to the first input of the comparison circuit, the second input of which is connected to the output of the first integrator, the first input of the storage device is connected to the output of the comparison circuit, and the second to the output of the divider, OMe order unit with an adjustable transmission ratio is designed as a multiplier to the second input of which is supplied with the output voltage of the memory device is proportional to the desired transmission ratio,

Comparative analysis with the prototype shows that the inventive device is distinguished by the presence of new units: a divider, a storage device, a comparison circuit, a second integrator, a link with a constant transmission coefficient, a form of execution of a link with an adjustable transmission coefficient, and links of new blocks with other elements of the circuit. Thus, the claimed device meets the criteria of the invention of novelty,

Comparison of the technical claimed solution with other technical solutions shows that the divider, storage device, comparison circuit, integrator, link with a constant transmission coefficient are widely known.

However, when they are introduced in this connection with the remaining circuit elements into the inventive device for measuring the characteristics of magnetic materials, the above blocks exhibit new properties, which leads to an increase in the speed of the test process - this allows us to conclude that there are significant differences between the technical criteria.

In FIG. 1 is a block diagram of a device for measuring the magnetic characteristics of materials; in FIG. 2 - section of the hysteresis loop of the magnetic material from which the test sample is made, as the dependences of the induction B and magnetization M on the strength of the internal and external magnetic fields.

A device for measuring the characteristics of magnetic materials (Fig. 1) contains a magnetizing device (block) 1, to the output of which a magnetizing system 2 and a voltage transducer 3 are connected in series

5 external magnetic field, magnetization measuring transducer of the test sample 4, consisting of measuring 5 and compensating 6 windings, the first integrator 7, connected to the output of the magnetization measuring transducer registering device 8, amplifier 9, connected to the output of voltage measuring transducer 3, adder 10, the first input of which is connected to

5 to the output of amplifier 9, and the output to the first input of the recording device 8, the second input of the last connected to the output of the first integrator 7, link 11 with an adjustable transmission coefficient, the output of which

0 is connected to the second input of the adder 10, and the first input to the output of the first integrator 7. In addition, the device contains a divider 12, a storage device (block)

13. the second integrator 14, link 15 with a constant transmission coefficient, comparison circuit (block) 15, and the input of the second integrator 14 is connected to the output of the measuring winding 5, the first input of the divider 12 is connected to the output of the amplifier 9, and the second to 0 the output the first integrator 7 input link 15 with a constant gear ratio, connected to the output of the second integrator

14. and the output to the first input of the comparison circuit 16, the second input of which is connected to

5 to the output of the first integrator 7, the first input of the storage device 13 is connected to the output of the comparison circuit 13, and the second to the output of the divider 12, and the link 11 with an adjustable transmission coefficient is made in the form

0 of the multiplier, to the second input of which the voltage is supplied from the output of the storage device 13, which is proportional to the required transmission coefficient.

The device operates as follows.

The test sample 4 is magnetized by the limit hysteresis loop under the action of an external magnetic field created by the magnetizing system 2 under the action of the current coming from the output

of the magnetizing device 1. Measuring information on the rates of change of the magnetization and induction of the test sample 4 is supplied to the inputs of the first 7 and second 14 integrators, respectively, from the outputs of the magnetization measuring transducer and measuring winding 5. A signal proportional to the strength of the external magnetic field comes from the output the voltage transducer 3 to the input of the amplifier 9. The first and second inputs of the divider 12 are supplied with voltage proportional to the external magnet the total field and magnetization of the sample 4. The output signal of the divider 12 is the quotient of the division of the external magnetic field He and the magnetization M and is supplied to the second input of the storage device 13. At the inputs of the comparison circuit 16, voltages proportional to the magnetization and induction multiplied by the transfer coefficient of link 15 with a constant transfer coefficient equal to 1 / / u0 (4d GN / m - vacuum magnetic permeability). At the moment of equal voltage at the inputs of the comparison circuit 16 from its output, a control signal is issued to the first input of the storage device 13 to remember the voltage supplied to the second input, It is proportional to the demagnetization coefficient N of this test sample 4, As a result, from this moment in time, the link coefficient 11 is set at link 11 with an adjustable transmission coefficient under the control of the memory device 13, which is equal to the demagnetization coefficient N of the test sample 4, In turn, the sum Mathor 10, having a transmission coefficient of 1 and -1, respectively, at the first and second inputs.

Thus, the recording device captures the characteristic of the magnetic material M (H) from which the test sample is made.

Devices for measuring the characteristics of magnetic materials can be performed, for example, as follows:

-magnetizing device 1 in the form of a source of pulsed magnetic alternating field;

- magnetizing system 2 in the form of a solenoid;

- an external magnetic field strength meter in the form of a shunt;

- a magnetization measuring transducer, consisting of measuring 4 and compensating windings, similar to that described in the prototype;

- an oscilloscope or a two-coordinate recorder can be used as a recording device;

- the divider 12 and the link 11 with an adjustable transmission coefficient can be performed on integral multipliers x type K525PS1;

- the storage device can be performed on the integrated circuit K1100SC2;

- Comparison circuit 16 may be performed on an integral comparator of type K554CAZ;

- the link with a constant transmission coefficient can be performed on the operational amplifier K140UD17. The use of inventive devices for measuring the characteristics of magnetic materials in comparison with a device of a similar purpose (prototype) allows testing magnetic samples with greater productivity by automating the process of constructing a link with an adjustable transmission coefficient.

Claims (1)

SUMMARY OF THE INVENTION A device for measuring the magnetic characteristics of materials, comprising a magnetizing unit, the outputs of which are connected in series to a magnetizing system and a voltage measuring transducer, as well as a magnetization measuring transducer in the form of series-connected measuring and compensating windings, the first integrator whose input is connected to the output of the measuring magnetization converter, recording device, amplifier, the input of which is connected the output of the measuring voltage transducer, the adder, the first input and output of which is connected respectively to the output of the amplifier and to the first input of the recording device, the second input of which is connected to the output of the first integrator, a link with an adjustable transmission coefficient, the output and the first input of which is connected to the second the adder input and the output of the first integrator, respectively, characterized in that, in order to increase productivity, it is equipped with a divider, a storage unit, a second integrator, a link with a constant transfer coefficient and a comparison unit, while the input of the second integrator is connected to the output of the imitation winding, the inputs of the divider are connected to the output of the amplifier and the output of the first integrator, the input and output of the link with a constant transmission coefficient, the connecting block is connected to the output respectively, to the output of the second integrator-comparison block and the output of the divider, corresponding to the first input of the comparison block, which is second to the second input of the link with the control input of which is connected to the output by the first transfer coefficient integrator, the first and second inputs zapo-5 connected the output of the storage unit .2