SU832504A1 - Digital magnetic induction meter - Google Patents

Description

(54) DIGITAL MAGNETIC INDUCTION METER

The invention relates to the field of magnetic measurements and can be used for precision measurements in a wide range of induction of constant magnetic fields.

A magnetic induction meter is known, which consists of a Hall sensor of an alternating current source for feeding a Hall sensor, an additional coil, in the field of which a Hall sensor is located. a DC source to power the coil of the auxiliary coil, voltage-code converter, reversible counter, dividing device, control device, and digital reading device; in which a voltage-code transformer is connected between the Hall sensor, a reversible counter and a separating device, the second input of which is connected to the output of a reversible counter, and the output to a digital reading device, the control device is connected to a voltage-voltage converter, a separating device, reversible counter, DC source and digital reading device l.

The measurement cycle in a known device consists of two cycles. In the first cycle, the Hall sensor is simultaneously affected by two permanent magnetic fields: measured B and additional B (x created by an additional coil in which there is a Hall sensor. A current from a DC source flows through the winding of the additional coil. Hall sensor output signal proportional to the sum of the magnitudes of the magnetic inductions {B,, is fed to the voltage-code converter, from where it is transmitted to a reversible counter counting in the forward direction as a sequence of pulses. tchik Hall effect only the measured magnetic field. The output of the sensor proportional to the measured magnetic flux density is applied to the voltage converter code from which a pulse sequence is outputted by reversible counter, counting in the opposite direction.

The drawbacks of the device are the dependence of the measurement results on the direction of the measured magnetic field and. unreliability of the results of measurements in the case of non-coincident in the direction of the measured and additional magnetic fields, as well as in excess of the induction of the additional magnetic field of the induction of the measured magnetic field, the purpose of the invention is to increase the accuracy of the measurement. The goal is achieved in that a digital magnetic induction meter containing a sequential, connected AC source, a Hall sensor, a controlled voltage divider / converter code, a reversible counter, a dividing unit and a digital reading device are connected in series and a source of direct current, an additional coil connected to the output and input of the Hall sensor, the phase element, through three hernia of polarity, connected to the second input of the controlled divider, at the same time The inputs of the converter-code, reversible counter, digital reading device, dividing unit and the switch input are connected to the control unit, and the second output of the voltage converter-code is connected to the third input of the dividing unit, additionally setting the syncation unit and automatic switch connected between the auxiliary coil and the DC source, and the in-phase coupler is connected between the outputs of the phase element, the output of the control unit and the third input a -automatic switch. Figure 1 shows the block diagram of a digital magnetic induction meter; in fig. 2 - time diagrams of the device operation. Digital magnetic meter. induction consists of (figure 1) Hall sensor 1, alternating current source 2, constant source 3, tska, additional catuka 4, controlled divider 5, phase 3Jier.eHTa b, trigger 7 polarity of the voltage-code converter 8, a reversible counter 9, a dividing unit 10, a digital reading device 11, a control unit 12 of the switch 13, an in-phase detection unit 14 and an automatic switch 15 .. The device works as follows. The phase element, b, depending on the direction of the measured magnetic field, sets the trigger of polarity 7 to a certain state. For example, in the positive direction, the control signal of the phase element b is fed to the unit trigger 7. The polarity trigger 7 outputs it to the state corresponding to the positive direction of the magnetic field. In the negative direction of the magnetic field, the control signal of the phase element 6 is fed to the zero input of the polarity trigger 7. The trigger 7 of polarity establishes a controllable divider 5 V, the state corresponding to a negative voltage. the magnetic field. If, with a negative direction, the magnetic field sensitivity of the Hall sensor 1 is greater than with a positive direction, then the transfer coefficient of the controlled divider 5 with a negative direction is less than one, provided that with a positive direction, it is taken: one. With the inverse ratio, the transmission coefficient in the negative direction is magnetic more than one. The measurement cycle of the device consists of two cycles. In the first cycle, the Hall sensor 1 is acted upon by a measurable magnetic field B7, m V, the output signal of the Hall sensor 1 through a controlled divider 5 is fed to a voltage-code converter 8, from where it arrives in the form of a sequence of pulses to a reversible counter 9, which in the first tact is working on subtraction. Reversible counter 9 - fixes a negative code N, proportional to the measured magnetic induction. The N code of the output register of the voltage converter code 8 is supplied to one of the inputs of the dividing unit 10. In addition, in the first measurement cycle of the in-phase matching unit 14, the state of the phase element 6 determines the direction of the measured magnetic field,. Depending on the direction of this field, the in-phase matching unit 14 is set to one of two positions. In the positive direction, the current from the DC source 3 flowing through the additional coil 4 has one direction. With a negative direction from the source 3 grinding B, there is no its own direction. Therefore, the field created by the additional coil 4 always coincides in direction with the measured constant magnetic field. In the second cycle, the Hall sensor 1 operates, two constant magnetic fields: the measured B and the additional .. created by the additional coil 4, the field of which is located in the Hall sensor 1. Through the winding of the additional coil 4 a current flows from the source 3 of direct current, which is switched on by the switch 13, to which the control signal from the control unit 12 is supplied. The output of the Hall sensor 1, proportional to the sum of the values (Byjj,), is fed to the voltage-code converter 8, from where it is fed to a reversible counter 9, counting in the forward direction, as a sequence of pulses. As a result, after the second clock cycle, the reversible counter 9 records the number of pulses S ,, c, the proportional to the additional additional magnetic field, Bq, After two measurement cycles, the second input of the dividing block 10 receives the code Njc of the reversible counter 9 the operation of dividing the number of Nj,

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The result of the division, equal to N Vdv, does not depend on the specific sensitivity of the Hall sensor to induction, its supply current, the circuit transfer coefficient and the direction of the measured

If value

magnetic field B

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induction of an additional magnetic field taken as a unit of measured magnetic induction, the result of the division is proportional to the measured magnetic induction.

The use of an in-phase setting unit and an automatic switch favorably distinguishes the proposed digital magnetic induction meter from known devices, as it allows to increase the accuracy and reliability of measurement measurements. The application of the proposed meter allows you to fully automate the measurement process and significantly increase labor productivity when removing the magnetic field topography of devices of complex configuration, when the measurement process changes,

direction. magnetic field acting on the Hall sensor.

Claims (1)

Invention Formula A digital magnetic induction meter containing a series-connected AC source, a Hall sensor, a controlled divider, a voltage converter, a reversible counter, a dividing unit and a digital reading device, a series-connected switch and a DC source, an additional coil connected to the output and the input of the Hall sensor phase element, through the trigger field rnesd-and connected to the second input of the controlled dividers, l, this is the second inputs of a voltage-code converter, a reversible counter, a digital reading device, a dividing unit, and an input. the switch is connected to the control unit, and the second output of the voltage-code converter is connected to the third input of the dividing unit, characterized in that, in order to improve the measurement accuracy, the unit is additionally inserted synchronicity switch and an automatic switch, connected between the auxiliary coil and the DC source, and the synphasization unit is connected between the output of the phase element, the output of the control unit and the third input of the automatic switch. Information sources, taken into account in the examination 1, USSR Author's Certificate 347704, cl. G 01 R 33/06, 1972. ESsn thing eII U5 “- trI-. tf U-ft