SU1377788A1 - Device for measuring losses in reversal of magnetization of magnetic materials - Google Patents

Abstract

The invention relates to a measurement technique, more precisely, to a technique for testing magnetic materials in alternating magnetic fields, and is intended to measure reversal magnetization losses in samples of magnetic materials and products thereof. The purpose of the invention is to increase accuracy by eliminating the load component of the current of the measuring circuit. The electrodynamic wattmeter has a second current winding, which is connected in series with the measuring winding. 1 il. I (L

Description

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The invention relates to a measurement technique, in particular, to a technique for testing magnetic materials in alternating magnetic fields, and is intended to measure reversal magnetization losses in samples of magnetic materials or in products thereof.

The purpose of the invention is to improve accuracy.

The drawing shows a diagram of the proposed device.

The device contains an AC power source. (Not shown) to which terminals 1 are connected, magnetizing 2 and measuring 3 windings, voltmeter 4 for determining induction in the sample, wattmeter 5 with two TOKOBbiMH windings 6 and 7 and voltage winding 8.

The principle of operation of the device is as follows.

The test sample with magnetizing and measuring windings is a single-phase transformer, the magnetizing winding current of which, besides the magnetizing component (sample magnetization current), also contains a load component that is numerically equal (when the number of turns of the windings is) to a current meter. windings. If to measure the reversal loss of a sample with two windings having the same number of turns, use a wattmeter, the current winding of which has two identical independent windings, and one of them should be connected in series with the magnetizing winding of the sample, and oppositely relative to current in the measuring winding and the load component of the current of the magnetizing winding of the sample, the resultant current (current) of the current winding of the wattmeter contains only the magnetizing current moiety is the current sample of the magnetizing coil, and the movable part acts wattmeter moment proportional loss of m in the specimen, i.e., The wattmeter measures only the losses by remagnetization of the sample. In the drawing, the dots indicate the polarity of the connection of the windings of the meter and the sample, which ensures the correct operation of the device.

It is also possible to use a wattmeter with two identical current and two identical windings for example

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got married In this case, the voltage windings may be interconnected in series or in parallel, which extends the voltage measurement range.

The variant with two identical current and two identical windings of the wattmeter voltage can also be used when performing measurements on samples with an unequal number of turns of the magnetizing and measuring windings. However, in this case, it is necessary to take measures to fully compensate the components of the torque acting on the moving part of the wattmeter, proportional to the current of the measuring winding and the load component of the current of the sample magnetizing winding, for example, by including an additional resistance with one voltage winding interconnection, as well as by shunting one of the windings of a voltage with a resistance when connected in series with each other.

When performing measurements on samples with an unequal number of turns of the magnetizing and measuring windings, in some cases it may be advisable to use a wattmeter with a different number of turns or current windings or voltage windings.

Claims (1)

When using a wattmeter with two current windings and one or two voltage windings, the measurement accuracy is improved, the measurement procedure is simplified, since there is no need to calculate the result of the measurement of the magnetization reversal loss from the readings of two devices — a wattmeter and a voltmeter. Especially effective is the use of the proposed device when performing measurements on small-sized samples weighing 1-2 kg or less, when the losses in the devices become commensurate with the sample re-magnetization losses, which increases the measurement error several times and limits the scope of application of the known device. Invention Formula A device for measuring the magnetization reversal loss of magnetic materials, containing an electrodynamic wattmeter with a first current winding and a voltage winding, a magnetizing winding connected in series with the current winding in an AC source circuit, and a measuring winding connected in parallel with the voltage winding and the entrance A voltmeter, characterized in that, in order to increase accuracy by eliminating the load component of the current of the measuring circuit, a second current winding is inserted into the wattmeter, which is connected in series with the measuring winding.