SU746358A2 - Magnetic induction digital meter - Google Patents

Description

one

The invention relates to devices for magnetic measurements and is intended for precision measurement in a wide range of induction of constant magnetic fields.

According to the main author. St. No 347704 A digital magnetic induction meter is known, which contains a Hall sensor, an alternating current source for powering a Hall sensor, an additional coil, in the field of which is a Hall sensor, a direct current source for powering a coil, a voltage-code converter, a reversible a counter, a dividing device, a control device and a digital reading device in which a voltage-code converter is connected between the Hall sensor, a reversible counter and a dividing device, the second input to torogo connected to the output of down counter and an output - to a digital reading device, the control device is connected to converter voltage code divider ,, down counter, a source of DC and the digital device.

However, in this meter, the measurement results depend on the direction of the measured magnetic field and, if there is a discrepancy in the direction of the measured and additional magnetic fields, are unreliable.

The purpose of the invention is to improve the accuracy and reliability of measurement results.

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The goal is achieved by introducing a trigger with a counting input, two AND elements, a polarity trigger, a phase element and a controlled divider, the output of the Hall sensor is connected to one of the inputs of the phase element, the second input of which is connected to the source output. AC directly, and with the voltage-code converter through a controlled divider, the second input of which is connected to the output of the polarity trigger, the outputs of the phase element are connected to the corresponding inputs

25 polarity trigger directly, and through the corresponding elements And to the trigger inputs with a counting input, the output of which is connected to one of the inputs of the reversible counter, with the other inputs of the elements And and trigger 30

The Ёra1 :: bichetK1 input is connected to the control unit.

The drawing shows a functional diagram of a digital magnetic induction meter.

The digital meter contains a Hall sensor 1, an AC source 2 for powering a Hall sensor, a voltage-code converter 3, a reversible counter 4, a divider device 5, a digital reading device b, an additional coil 7, in which a Hall sensor is supplied from DC power supply 8, and control unit 9, b1-.

The kesit of which is connected to the inputs of the separating device 5, the digital 15 reading device b, the reversing counter 4, the voltage-code-converter 3 and the DC source 8, one of the outputs of the voltage-3 converter 3 is connected to one from the inputs of the reversible counter 4, and the other output - with one short-circuit INPUTS: a dividing device 5, the other input of which is connected to the output of the reversible counter LD 4, and the output to the input of the digital readout device b, and trigger 10 with a counting input, two elements And 11 and 12, trigger 13 by polarity, the phase element 14 and controllable; de .- 30, motor 15, the output of Hall sensor 1 is connected to one of the inputs of phase element 14, the second input of which is connected to the output of alternating current source 2 directly, and to the voltage-code converter through a controlled divider 15 , the second input of which is connected to the output of the trigger 13 polarity. The outputs of the phase element 14 are connected to the corresponding inputs of the trigger 13 of the half of the 40th mode, and through the corresponding elements of And 11 and 12 to the inputs of the trigger 10 with the counting input, which input is connected to one. from the inputs of the reversible counter 4. 45 Other inputs of the elements 11,12 and trigger 10 are connected to the control block 9.

The meter works as follows .50

Phase element 14 and the dependence on the voltage of the measured magnetic field B ,,,., Sets the trigger 13

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polylities in a certain state. For example, with a half-way direction jj, the control signal from phase element 14 is fed to a single input of trigger 13, which sends to the controlled divider 15 a signal that sets its state,

sbbotvstvuyuscheysya positive direction of the magnetic field. In the negative direction of the magnetic field, the control signal from the phase element 14 arrives at the trigger 13, the polarity trigger is set to 65

The controlled divider 15 is in the state corresponding to the negative direction of the magnetic field.

If, with a negative direction, the magnetic field sensitivity of the Hall sensor is greater than with a positive direction, then the transfer coefficient of the controlled divider 15 with a negative direction will be less than one, provided that with a positive direction it is taken as one. With the inverse ratio, the transmission coefficient in the negative direction of the magnetic field will be greater than one.

(The measurement cycle of this meter consists of two cycles. In the first cycle, the Hall sensor is simultaneously affected by two permanent magnetic fields: the measured B measurement and the additional B supplementary created by the additional coil 7 in which the Hall sensor is located. On the additional winding the coil 7 carries the current of the DC source 8. The output signal of the Hall sensor through the controlled divider 15, proportional to the algebraic sum of values (. + Bgon.), is fed to the voltage-code converter 3, from which in the form of a sequence the pulses are fed to the reversible counter 4, which, in the first clock cycle, is used for addition or subtraction.

The mode of operation of the reversible counter 4 in the first cycle is determined by the state of the phase element 14. When coinciding in direction. and Boon, (for example, in the positive direction of the additional magnetic field) the initial installation signal, coming from the control unit 9 to the inputs of the elements 11 and 12, passes through the element 11 at zero. In this case, the trigger 10 sends such a control signal to the reversible counter 4, in which it will work on addition. A reversible counter will fix the code N I, proportional to the sum of the magnetic inductions of the measured and additional fields:

 second, only the measured magnetic field acts on the Hall sensor. I since the control unit 9 turns off the DC source 8. The output of the Hall sensor through a controlled divider 15, proportional to the measured magnetic induction, is fed to a voltage-code converter, from where it is fed to a reversing counter 4 in the form of a pulse train.

Claims (1)

In the second cycle, the reversible counter 4 works on the reading. The direction of the counter changes according to the signal coming from the output of block 9 to the counting input of trigger 10. As a result, after the second clock, counter 4 will record the number of pulses N 2 proportional to the additional magnetic field Vaop .:,. VnJSKVbH.r.S V-VnSWm When unmatched in the direction of Exe. and V. (in the positive direction of the additional magnetic ICCP) the initial installation signal coming from the control device to the inputs of the elements 11 and 12 will pass through the element 12 to the single input of the trigger 10, which in this case gives the first measurement cycle to the counter 4 such a control signal, in which the reversible counter works on subtraction. Counter 4 will record a negative number N, proportional to the difference of magnetic inductions of the measured and additional fields: - (). In the second cycle, the reversible counter will work on addition. As a result, after the second clock cycle, counter 4 will record the number of pulses N, proportional to the additional magnetic field: - b (mHzz). “-Vit8” “, - t 6„ „5KL-vy5“. ZKT 6zop-2 t After two measurement cycles, the numbers of the 5 .5 dividing device receive numbers N from the output register of the converter 3 and Ng from the reversible counter 4. After receiving the control The separating device 5 performs the operation of dividing the numbers NJ by N. The result of dividing is US "1% 5 SK J,, goM will not depend on the specific sensitivity of the Hall sensor to induction, its current supply, circuit gain and near orientation of the measured and additional magnetic fields. If the induction value of the additional magnetic field is taken as the unit of the measured value, the result of the division will be proportional to the measured magnetic induction. Claims of the invention Puifra magnetic induction meter according to ed. St. 347704, in order to increase the accuracy and reliability of the measurement results, a trigger with a counting input, two AND elements, a polarity trigger, a phase element and a controllable divider, OUTPUT are introduced into it The Hall sensor is connected to one of the inputs of the phase element, the second input of which is connected to the output of the AC source directly, and to the transducer. voltage code through a controlled divider, the second input of which is connected to the trigger output of the polarity, the outputs of the phase element are connected to the corresponding polarity trigger inputs directly, and through the corresponding I elements to the trigger inputs of the counting input whose output is connected to one of the inputs of the reversible counter, the other inputs of the elements AND and the trigger with the counting input are connected to the control unit. 746358