SU400863A1 - DEVICE FOR MEASURING COERCITIVE FORCE - Google Patents

Description

one

The invention relates to the field of magnetic measurements and can be used to determine the coercive force of soft magnetic materials when they are re-magnetized in alternating magnetic fields.

Known devices for determining the CoE; the positive force, constructed according to the method of converting the phase shift between zero values of strength and induction of the test sample into a pulse duration, contain pulse shapers, a trigger, a circuit of measured pulse duration and a recording instrument. However, such devices have a significant error, VNOSimuyu scheme for converting the phase shift in the pulse duration and the scheme for measuring the pulse duration, as well as a narrow frequency range.

The proposed device allows high-precision measurement of the coercive force in a wide frequency range. This is achieved by introducing into it a sensor of time intervals and a circuit for measuring an instantaneous magnitude of the magnetizing field at the time of zero induction consisting of a random pulse generator, switch 1, co.parator, two pulse counters and a display unit.

The drawing shows the block diagram of the device.

2

The sample under test / is magnetized by means of the winding 2 from the alternator 3. Resistor 4 is supplied with a voltage that is proportional to the magnitude of the magnetizing field. The voltage from the measuring winding 5 is fed to the integrator 6, the output voltage of which is proportional to the magnitude of the magnetic induction in the sample. The voltages from the output of the integrator and the resistor are fed respectively to the 7 p. Comparator Fork 8. In the shaper, pulses are generated corresponding to moments of the zero induction value. The received pulses control the operation of the key 5

and a time interval sensor 10.

With simultaneous receipt of permissive pulses from the generator and the time interval sensor on the key, pulses from the generator // random impulses, whose amplitude is distributed according to a uniform law, are sent through 1 switch 9 to the input of the comparator and counter 12 of the total number of tests. From the output of the comparator, the pulses arrive at the counter / 5 of the number of favorable

tests.

When I1 of the counter 12 is filled, at its output a pulse is generated that arrives at the time interval sensor and corresponds to the end of the measurement cycle. At the same time

at the output of the sensor time intervals

3

a signal is generated that prohibits the operation of the key and permits the display in the display indication block 14 of the counter 13, which corresponds to the measured value of: capacitive force.

PRED: MEETH and W ote and

A device for measuring coercive force, containing a source of magnetizing field, a test sample with a magnetizing winding, connection to a resistor, and a measuring winding connected to an integrator connected to the IK of the pulse shaper, and an indicator that, in order to improve the accuracy of the pulse shaper, and the widening of the frequency range.

four

it is equipped with a time interval sensor and an instantaneous value measurement circuit consisting of a random pulse generator, a key, a comparator, and two pulse counters, one of which is connected between the comparator inlet and one indicator input, the other input is simultaneously connected to the output of the key and one input of the comparator, and the output with one of the inputs of the time interval sensor, the other input of which is connected to the output of the pulse former and one input of the key, the second input of the latter is connected to the output of the generator ora random pulses, and simultaneously the third input coupled to the output of the sensor slots and the other input of the indicator.