SU828135A1 - Method of measuring hall emf - Google Patents

Description

The invention relates to a magnetic measuring technique and can be applied in various instruments and devices for measuring magnetic quantities to eliminate the temperature and time instability of the parameters of the Hall sensors.

Methods are known for measuring the EMF of a Hall, based on the formation of a model additional magnetic field that is uniform with the measured magnetic field; the combined effect of the measured and additional magnetic fields on the Hall sensor; acting only on the measured magnetic field on the Hall sensor; converting an input signal into an electrical signal by a Hall sensor; determining an electrical signal proportional to the additional magnetic field at the output of the Hall sensor; determining the electrical signal at the output of the Hall sensor, proportional to the measured magnetic field; elimination of the multiplicative error from the measurement result by dividing the signal, proportional to the measured magnetic zero, by a signal prolortional to the exemplary additional magnetic field 1.

The device implementing this method consists of a Hall sensor, its power source, an additional coil, in

the field of which contains the Hall sensor, the source of the additional coil, the dividing device and the digital reading device.

The measurement cycle in this device consists of two cycles. In the first cycle, the Hall sensor is simultaneously affected by two magnetic magnetic fields: measured and additional, created by the additional coil, in which the Hall sensor is located. The output of the Hall sensor, proportional to the sum of the magnitudes of the magnetic inductions, is fed to a voltage-to-voltage converter, from which, as a sequence of pulses, is fed to a reversible counter counting in forward direction.

In the second cycle, only the measured magnetic field acts on the Hall sensor. The output of the Hall sensor, proportional to the measured magnetic induction, is supplied by a voltage-to-voltage converter — a code, from which, as a sequence of pulses, is output to a reversible counter, I count it in the opposite direction.

After two measurement cycles, the signals from the output register of the voltage-code converter and from the reversible counter are fed to the inputs of the separating device. The result of the division will not depend on the specific sensitivity of the Hall sensor to induction, its current and the transmission coefficient of the circuit. If the inductive 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.

The disadvantage of this method is the dependence of the measurement results on the direction of the constant magnetic field relative to the Hall sensor and the unreliability of the measurement results when the magnetic fields do not match in direction, as well as when the level of the additional magnetic field exceeds the level of the magnetic field.

The purpose of this invention is to improve the measurement accuracy.

The goal is achieved by measuring the EMF of the Hall, using the method of BaiHHbiM to form an exemplary additional magnetic magnetic field uniform with a measured magnetic field, combined with the Hall sensor of the measured L exemplary additional magnet of the first fields, acting on the Hall sensor of the measured magnetic field alone. , conversion by the Hall sensor of the input action into an electrical signal, dividing the signal, pronounced magnetic zero, on the signal, aronortional exemplary th magnetic field direction determined .dopol.pntelpogo magnitpogo floor iairavleiie the measured magnetic field with respect to the direction of further exemplary magnetic field measured nanravlena1e additional exemplary magnetic field to coincide with the direction pzmer emogo magnetic field.

The drawing shows the block diagram of the device that implements this method.

The method of measuring the EMF of the Hall includes the following operations: formating an exemplary additional magnetic field, homogeneous with the measured, combined effect on the Hall sensor of the measured and additional exemplary magnetic fields, effect on the Hall sensor of the measured magnetic iol only, converting the input effect to the Hall sensor signal, determination of an electrical signal proportional to an exemplary additional magnetic zero at the output of the Hall sensor, determination of an electrical signal and the output of the Hall sensor, which is proportional to the magnetic emomu measured zero, the elimination of the multiplicative error from the result of measurement by dividing the signal proportional to the measured magnetic field emomu on signal proportional exemplary dopolrp p-Yelnia magnetic field; 01 determine the direction of the additional sample magnetic field, determine the direction of the measured magnetic zero relative to the direction of the additional standard magnetic zero, change the direction of the coarse magnetic field so that it coincides with the direction of the measured magnetic field.

iol

A device that implements the method of measuring the emf consists of a Hall sensor}, a source of filament 2, an additional coil 3, in which there is a sensor

/ (oll 1, power source of the additional coil 4, determinant of the additional magnetic field 5, determinant and direction of the measured magnetic field 6, automatic switch

7,) synchronizer 8, transmitter, ia code - 9, reversible counter 10, dividing device /., Digital counting device 12 and control device 13.

The device works as follows.

The initial setup signal from control unit 13, schemei; a, is reset.

During the first measurement cycle, only the measured magnetic field acts on the Hall sensor. At this point in time, the determinant g: the direction of the measured magnetic zero 6 determines the direction of the measured magnetic zero.

In the second cycle, the Hall sensor is affected by two nostow magnetic zeros and an additional one created by the additional coil 3, in which the Hall sensor is located. A current from the DC source 4 flows through the winding of the additional coil, which is switched on by the signal of the control device 13 in the second cycle. The determinant of the direction of the additional field 5 finds the direction of the additional magnetic field and, depending on this direction, gives a certain command signal to the in-phase driver 8. At mismatch between the direction of the measured and the additional magnet fields, the in-phase former 8 switches the switch 7. This changes the direction of the current, flowing through the additional roller 3, which leads to a change in the direction of the additional magnetic field, i.e. it will coincide in direction with the measured magnetic field. In the third cycle the sensor output signal

Hall, proportional to the sum of the magnitudes of the magnetic inductions, is fed to the voltage converter — code 9, from which it is output to a reversing counter, 10, counting in the forward direction as a sequence of pulses.

/ У, 5Г „й (5., з., + БД„ „).

In the fourth cycle on the Hall sensor 1. only the measured magnetic field is in effect, since the source of the nitanes of the additional coil 4 is turned off by the signal of the control device 13. The output signal of the Hall sensor /, proportional to the measured magnetic induction, is fed to the voltage-to-code converter

9, from where, as a sequence of pulses, is output to a reversible counter

10, counting in the opposite direction.

As a result, during the fourth cycle, the reversible counter 10 records the number of pulses proportional to the additional magnetic field.

L / 2 5, (/ p (oizm L-Odop) Lk / pO, I3M ---; podopOp four strokes to the outputs of the additional device 11, the numbers 5k / p5 are received from the output register of the transducer “tilt - code 9 and L2 - from the reversible counter 10. After the arrival of the contraction signal from the device 13, the dividing device // performs the operation of dividing the number by L2. The result of dividing does not depend on the specific sensitivity of the Hall sensor to the induction, its power supply current and the circuit transfer coefficient. floor take per unit measure of the magnitude of the magnitude, the result of dividing will be the measured magnetic induction.

Using the method of measuring the UDS Hall provides, in comparison with the known methods, the following advantages:

1) The ability to fully automate the measurement process, since it does not need to change the position of the sensor depending on the direction of the magnetic field. This significantly increases labor productivity. When the direction of the magnetic field acting on the Hall sensor changes in the measurement process, the measurement process is shortened by a time equal to (T + t), where T is the time for the sensor to change position, t is the measurement time for one sensor position. Thus, the application of this method allows to reduce the measurement time. If T t, the measurement time is reduced by 3 times.

2) The ability to measure accurately regardless of the magnetic field relative to the Hall sensor, where other measurement methods cannot be used due to the unique operating conditions of the Hall sensor, since they do not take into account the direction of the magnetic field acting on the Hall sensor.

Claims (1)

1. Author's designation of the USSR ° 347704, G 01 R 33/06, 1972 (prototype).