SU1644054A1 - Digital meter of magnetic induction - Google Patents

Description

one

(21) 4482101/21

(22) 07.15.88

(46) 04.23.91. Bul Number 15

(72) I. P. Smirnov, A. N. Foyda, O. T. Chigirin and Yu. T. Chigirin

(53) 621.317.44 (088.8)

(56) USSR Author's Certificate No. 347704, cl. G 01 R 33/06, 1972.

(54) DIGITAL MAGNETIC INDUCTION METER

(57) The invention relates to magnetic measurements and can be used for precision measurements in a wide dynamic range of induction of constant magnetic fields. The purpose of the invention is to reduce the measurement time by the introduction of two groups of 2-2-2I-ZILI 8, 9 circuits, two groups of 2-2I-2ILI 15, 16 circuits, a comparison unit 17, a register 11, a subtracting unit 7 and a control unit 14. The meter also contains a Hall sensor 1, a current regulator 2, an induction coil 3, a power source 4, a voltage-to-code converter 5, a reversible counter 6. a separating device 10, a digital device 12, a binary-decryption decoder 13. 2 Il.

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

The aim of the invention is to reduce the measurement time.

FIG. 1 shows a block diagram of a digital magnetic induction meter; in fig. 2 - timing charts of the control unit.

A digital magnetic induction meter consists of a Hall sensor 1, a current stabilizer 2, an induction coil 3 (additional) wound on a Hall sensor 1, a power source 4, a voltage-code converter 5, a reversing counter b, a subtractor 7, groups 8 and 9 2-2-2I-ZILI, dividing device 10, register 11, digital reading device 12, binary decimal decoder 13, control unit 14, groups 15 and 16 circuit 2-2IL-2ILI, and comparison circuit 17.

Control unit 14 has inputs and outputs 18-43 and consists of a pulse generator 44, AND circuit 45, counter 46, circuit OR 47, trigger 48, circuit OR 49, switches 50 and 51, decoder 52, circuit 53 and 54 and trigger 55.

The current electrodes of the Hall sensor 1 are connected to a current stabilizer 2. The potential electrodes of the Hall sensor 1 are connected to the signal input of the voltage-code converter 5.

The winding of the induction (optional) coil 3 is connected to the power source 4.

The output (coded) voltage-code converter 5 is connected to the first input of a group of 8 circuits 2-2-2I-ZILI, the first input of a group 15 of circuits 2-2I-2ILI, the first input of a group 16 of circuits 2-2I-2ILI and the first input of the circuit 17 comparisons. The output of the counting pulses of the voltage-code converter 5 is connected to the counting input of the reversible counter 6.

The output of the reversible counter 6 is connected to the second input of a group 15 of the 2-2I-ORI circuit, the second input of the comparison circuit 17 and the second input of the group 16 of the 2-2I-ORI circuit.

The output of the subtracting device 7 is connected to the second input of group 8 of the circuit 2-2-2I-ZILI and the first and second inputs of the group 9 of the circuit 2-2-2IL-ZILI. The first input of the subtracting device 7 is connected to the output of group 15 of circuits 2-2I-2ILI, the second input - to the output of group 16 of circuits 2-2I-2IL.

The third input of group 8 of the circuit 2-2-2IL-ZIL and connected to the output of the register 11. The output of group 8 of the circuit 2-2-2IL-ZILI is connected to the first input of the dividing device

10, the second input of which is connected to the output of group 9 of 2-2-2I-ZILI circuits, and the output to the first input of binary-decoding decoder 13, the input of register 11 and the third input of group 9 of 2-2-2IL-ZILI circuits.

0 The output of the binary-decryptor 13 is connected to a digital reading device 12.

The first output 18 of control unit 14 is connected to a source control input.

5 4 power supplies, the second output 21 - with the first control input of group 8 of the 2-2-2-ZILI circuits, the third output 22 - with the second control input of the group 8 of the 2-2-2-ZILI circuits, the fourth output 23 - with the third

0 control input of group 8 of the circuits 2-2-2I-ZIL And, the fifth output 20 - with the triggering input of the converter 5 voltage – code, the sixth output 19 - with the control input of the binary decipher 13,

5 the seventh output 27 - with zero input of the dividing device 10, the eighth output 26 - with the dividing input of the dividing device 10, the ninth output 31 - with zero input of the reversing counter 6 and zero input

0 subtractive device 7, decimal output 32 - with the input of the reverse of the reversible counter 6, eleventh output 33 - with the first control input of group 9 of the circuit 2-2-2IL-ZILI.

5 The twelfth output 34 of the control unit 14 is connected to the second control input of group 9 of the circuits 2-2-2AND-ZILI, the thirteenth output 35 - with the third control input of the group 9 of the circuits 2-2-2ID-ZILI,

0 fourteenth output 24 - with zero input of register 11, fifteenth output 25 - with control input of register 11, sixteenth output 30 - with control input of reversing counter 6, seventeenth output 5, stroke 36 - with the first input of group 16 of 2-2I circuits 2IL and the second input of group 15 of circuit 2-2I-2ILI, eighteenth output 37- with the second input of group 16 of circuit 2-2I-2ILI and the first input of group 15 of circuit 2-2-2OIL, nineteenth output 28 - with control input of subtractor 7 , the twentieth output 29 - with the installation input of the subtracting device 7, the input 38 - with the output of the comparison circuit 17 .

5 Output decoder 52 from first to

Eighteenth respectively connected to the outputs of the control unit from the first to the eighteenth. The nineteenth output 43 of the decoder 52 is connected to the first input of the circuit OR 47 whose second input is connected to the twentieth output 42 of the decoder 52.

The output of the generator 44 pulses connected to the first input circuit And 45, the second input of which is connected to the output of the trigger 48. The output of the circuit 45 is connected to the counting input of the counter 46, the zero input of which is connected to the first input of the circuit OR 49 and the first input of the switch 51. The output of the counter 46 is connected to the input of the decoder 52.

The output of the circuit OR 47 is connected to the counting input of the trigger 48, the zero input of which is connected to the output of the circuit OR 49. The second input of the circuit OR 49 is connected to the first input of the switch 50. The second inputs of the switches 50 and 51 are connected to the common point (housing) of the device.

The first inputs of the circuits And 53 and 54 are connected to the input 38 of the control unit 14. The output of the circuit 53 is connected to the first input of the trigger 55, the second single input of which is connected to the output of the circuit 54. The control input of the circuit 53 is connected to the twenty-first output 40 of the decoder 52, the twenty-second output 39 of which is connected to the control input of the circuit 54 The zero input of the trigger 55 is connected to the twenty-third output 41 of the decoder 52.

The control unit 14 generates two types of control signals that synchronize the operation of the device: unchanged control signals; varying control signals depending on varying operating conditions,

The unchanging control signals include:

signal arriving at the first output

18, the power supply 4 is turned off by this signal;

the signal arriving at the second input 21, this signal is used to receive a code by a group of 8 circuits 2-2-2IL-ZILI with a voltage-code converter 5;

the signal arriving at the third output 22, this signal is used to receive the code by group 8 of the 2-2-2I-ZILI circuit from the subtractor;

the signal arriving at the fourth output 23, on this signal, the code is received by a group of 8 circuits 2-2-2И-ЗИЛИ from register 11;

the signal arriving at the fifth output 20 starts up voltage-code converter 5 from this signal;

signal to the sixth output

19, this signal is used to read the measurement result by the digital counting device 12;

the signal arriving at the seventh exit 27 is reset to zero by the dividing device 10;

the signal arriving at the eighth output 5 26 is divided according to this signal in the device 10;

the signal arriving at the ninth output 31, on this signal, the reversing counter 6 and the subtractive 10 of the device 7 are zeroed;

. the signal arriving at the tenth output 32, by this signal, the reverse of the reversing counter 6 is switched;

a signal arriving at the output 30, according to 15 of this signal, the counting pulses are received in the reversing counter 6;

the signal arriving at the entrance 33, according to this signal, the code is received by a group of 9 circuits 2-2-2И-ЗИЛИ from the subtractive device 7;

the signal arriving at the output 34, this signal is used to receive the code by group 9 of the 2-2-2I-ZILI circuit from the subtractor 7;

5, the signal from the output 35, this signal is used to receive the code by group 8 of the 2-2-2I-ZILI circuits from the dividing device 10;

the signal arriving at the output 28, according to this signal, receives the code in the subtractive device 7;

the signal arriving at the output 29, on this signal, subtracts two parallel codes in the subtractor 5;

the signal arriving at the output 24, according to this signal, the register 11 is reset;

the signal arriving at output 25, at 0, this signal receives the code in register 11.

Variable control signals include:

a signal arriving at the output 36, according to this signal 5, a code is received by a group of 16 circuits 2-2I-2ILI from a reversible counter 6 and a group 15 of circuits 2-2I-2ILI from a voltage-code converter 5;

A signal arriving at output 37, according to this signal, is received by group 15 of circuit 2-2I-2IL, or code is received from voltage-code converter 5 and group 16 of circuit 2-2I-2IL or from reversing counter 6.

5 The generation of variable control signals is performed according to the state of the comparison circuit 17, the signal with which is fed to the input 38 of the control unit 14. For operation of the control unit 14, control signals are generated at the outputs

39-43 decoder from the nineteenth to the twenty-third.

The operation of a digital magnetic induction meter occurs in a few. Contacts switching.

By pressing the button of the switch 51, the device is reset. At the same time, the counter 46 is zeroed, the trigger potential to the circuit 45 is output from the trigger 48. And the circuit 45 to the input of the counter 46 begins to receive signals from the generator 44 pulses. The decoder 52 analyzes the state of the counter 46 and provides control signals to all units of the device.

The signal from the output 31 of the control unit 14 sets the reversible counter 6 and the subtractive device 7 to zero. The signal from the output 26 of the control unit 14 sets the separating device 10 to zero. The signal from the output 24 of the block 14 control sets the register to the zero state. The signal coming from the output 41 of the decoder 52 sets the trigger 55 to the zero state.

In the first switching cycle, the Hall sensor 1 is in the gap of the magnetic circuit for some time sufficient for the temperature of the object under study, i.e. the gap of the magnetic circuit, to be set in the entire volume of the measuring probe with the Hall sensor 1. At this time, the Hall sensor 1 is acted upon by two permanent magnetic fields: measured with induction B and additional with induction Bpfi created by the induction coil 3 wound around the Hall sensor 1 through which current flows from the source 4 of the power supply. The output signal of the Hall sensor 1. is proportional to the algebraic sum of magnetic inductions (± В 4-Врц), is supplied to the voltage-code converter 5. The analog-to-digital conversion in the converter 5 takes place according to signals input to the converter 5 from the output 20 of the control unit 14.

The analog signal of the Hall sensor 1 is converted into the number of pulses that arrive from converter 5 to the counting input of a reversible counter 6 counting in the forward direction:

Ni Sin K (V ± B). where In is the power supply current of the Hall sensor:

S is the Hall sensor induction sensitivity.

Permission to receive pulses from converter 5 to counting input rever5

Sive counter 6 generates a signal from the output 30 of the control unit 14.

In the second switching cycle, only the measured magnetic field with induction B acts on the Hall sensor 1, since the signal from the output 18 of the control unit 14 switches off the power supply 4. In this case, no current flows through the induction coil 3, which excites a magnetic field with induction Vrc. The output signal of the Hall sensor 1, proportional to the magnetic induction B, is fed to the converter 5.

In the output register of the converter

The 5 5 voltage code sets the code N2, corresponding to the magnetic induction B:

N2 S In KB.

With a positive direction of magnetic induction B, when the direction of the measured magnetic induction B coincides with the direction of the additional magnetic induction, the code is equal to:

Ni (B + Bpfi) KS In. With a negative direction of magnetic induction & dts, i.e. when the direction of measured magnetic induction B is opposite to the direction of additional magnetic induction B, code NI

0 equals:

Mt (V-Vdm) K51p. Thus, with a positive direction of magnetic induction Ni N2, with a negative - Ni N2.

5, Comparison 17, compares the Ni code coming from the reversible counter 6 and the No. code. voltage-code arriving from the transducer 5. With positive directions of magnetic induction, when

Q NI N2. The comparison circuit 17 outputs a positive polarity signal to the input 38 of the control unit 14.

This signal is fed to the inputs of the circuits 53 5 and 54. When the control signal from the output 40 of the decoder 52 arrives, the And 53 circuit is triggered. The output signal of the And 53 circuit arrives at the single input of the trigger 55 and puts it into the unit state. At 0 this, a positive polarity signal (resolving potential) is output from output 36, and a negative polarity signal (inhibitory potential) is output at output 37. In this case, the first input 5 of the subtracting device 7 receives the code Ni from the reversible counter 6 through a group of 16 circuits 2-2I-2IL. and the second input is the code from the voltage-to-voltage converter 5 through group 15 of circuits 2-2 and 2IL. Permission to enter codes Ni and number to subtract

the device 7 outputs a signal from the output 28 of the control unit 14.

In the subtracting device 7, the N3 Ni-N2 (B + BAu) codes KlnS-B are subtracted. In K lnS S.

With the negative direction of magnetic induction B, when NI N2, the comparison circuit 17 outputs a positive polarity signal to the input 38 of the control unit 14. This signal arrives at the circuits And 53 and 54. When the control signal arrives from the output 40 of the decoder 52, the circuit 53 does not work, because the inhibitory potential arrives at its first input. At the same time, the output 36 of the control unit 14 is a signal of negative polarity (inhibitory potential), and the output 37 of the control unit 14 is a signal of positive polarity (permitting potential).

In this case, the first input of the subtracting device 7 receives the N2 code from the voltage-to-voltage converter 5 through group 16 of the 2-2I-2ILI circuits, and to the second input - the NI code from the reversing counter 6 through the 15Chem2-2I-2ILI group. In the subtracting device 7, the codes N3 No. - NI B Sin K - B Sin K (B - Vdn) S In K Vdi are performed.

At the first input of the dividing device 10, through group 8 of the circuits 2-2-2IL-ZILI, code N2 is received from the output register of the voltage-code converter 5. Permission to pass the code N2 through the group 8 of the circuit 2-2-2IL-ZILI generates a signal from the output 21 of the control unit 14. According to the signal from the output 33 of the control unit 14, the group 9 of the 2-2-2I-ZILI circuits is activated, the code Мз from the subtractor 10.

According to the signal from the output 27 of the control unit 14 in the device 10, the code N2 is divided by the code Mz. Dividing result equal to

No. | Ki

N3

Sln KBB

SlnKB u 1 VDK

enters the register 11. The permission to enter the N4 code into the register 11 generates a signal from the output 25 of the control unit 14. Then, the signal from the output 34 of the control unit 14 triggers group 9 of the 2-2-2I-ZILI circuit and the code M3 from the output of the subtractor 7 is fed to the second input of the dividing device 10.

In the second switching cycle, when the signal appears at the output 42 of the decoder

52, the OR 47 circuit is triggered and outputs a signal to the counting input of the trigger 48. The latter goes into one state and outputs a inhibitory potential to the AND circuit 45. As a result, the counting input of the counter 46 ceases to receive the counting pulses from the generator 44 pulses.

Then the Hall sensor is removed from the magnetic-permeability / Co gap of the magnetic circuit and placed in an environment with magnetic permeability // 0 (air). In this case, the magnetic core does not have a practical effect on the induction of an additional magnetic field created by induction

5 by coil 3. Since during the movement of the Hall sensor from the gap of the magnetic core with magnetic permeability (.1 /.10 to the medium with permeability // about the temperature of the measuring probe, in which the sensor

0 Hall 1 is almost unchanged, then the sensitivity of sensor 1 does not change, i.e. it will remain equal to 5.

Switch 50 is then pressed and the third switching cycle begins. Wherein

5, the trigger 48 is set to the zero state and allows the passage of signals from the generator 44 pulses and through the circuit 45 to the counter 46

In the third switching cycle on the sensor

0 Hall 1 two constant magnetic fields, an external magnetic field with induction Вв and an additional magnetic field with induction В p / i0, created by the induction coil 3

5 Output signal of the Hall sensor 1, proportional to the sum of the values (± Вв + В, цц0). voltage-to-code converter is supplied. Analog-to-digital conversion in converter 5 occurs according to signals input to converter 5 from output 20 of control unit 14. The analog signal of the Hall sensor 1 is converted into the number of pulses that arrive from converter 5 to the counting input of a reversible counter 6 counting in the forward direction:

N5 Sin K (BB + B pfi0),

The permission to receive pulses p from converter 5 to the counting input of the reversible counter 6 produces a signal from the output 30 of the control unit 14.

In the fourth switching cycle, only the external magnetic field with induction BB acts on the Hall sensor 1, since the signal from the output 18 of the control unit 14 switches off the power supply 4. At the same time through the induction coil 3 does not flow current, which excites a magnetic field with induction Вв. Output signal

0

Hall 1, proportional to the magnetic induction of IB, is fed to the converter 5. In the output register of the voltage-code converter 5, the code Ne is set corresponding to the magnetic induction BB:

Ne Sin Kvv.

With a positive direction of magnetic induction Вв, i.e. when the direction of magnetic induction Вв coincides with the direction of additional magnetic induction Врц0, code NS is equal to:

N5 (BU + Kin. With a negative direction of induction of an external magnetic field, i.e. when the direction of induction of an external magnetic field is opposite to the direction of additional magnetic induction, code N5 is equal to:

Ns (Вв - Вдмо) К 1П S. Thus, with a positive direction of magnetic induction N5 Ne. with a negative - N5 Ne.

The comparison circuit 17 compares the NS code coming from the reversible counter 6 and the Ne code coming from the voltage-code converter 5. If the magnetic induction direction of the external magnetic field is positive, when N5 Ne, the comparison circuit 17 outputs a positive polarity signal to the input 38 control block 14. This signal is fed to the inputs of the circuits And 53 and 54. When the control signal from the output 39 of the decoder 52 arrives, the And 54 circuit operates. The output signal of the And 54 circuit arrives at the single input of the trigger 55 and brings it to the unit state. In this case, a positive polarity signal (resolving potential) is output from output 36, and a negative polarity signal (inhibitory potential) is output at output 37.

In this case, the first input of the subtracting device 7 receives the NS code from the reversible counter 6 through group 16 of the 2-2I-21 / 1LI circuits, and to the second input - the code Ne from the voltage-5 converter-code through the group 15 of the 2-2I- circuits 2OR The permission to enter the Ns and Ne codes to the subtractor 7 generates a signal from the output 28 of the control unit 14.

In the subtractive device 7, the codes are subtracted: N7 (BB-BAM0) KlnS-BBK nS Vd0K1n5.

, With a negative induction direction of the external magnetic field, when Ns Ne, the comparison circuit 17 outputs a negative polarity signal to the input 38 of the control unit 14. This signal is sent to

0

five

And 53 and 54 circuits. When the control signal from the output 39 of the decoder 52 arrives, the And 54 circuit does not work, because the inhibitory potential arrives at its first input. At the same time, the output 36 of the control unit 14 is a signal of negative polarity (inhibitory potential), and the output 37 of the control unit 14 is a signal of positive polarity (permitting potential).

In this case, the first input of the subtracting device 7 receives the code Ne from converter 5 through group 16 of circuits 2-2I-2ILI, and to the second input - the code NS from the reversible counter 6 through group 15 of circuit 2-2I-2IL,

In the subtracting device 7, the codes are subtracted: N7 Ne - N5 Вв К In S - In KS (BB -) In К S Вдм0.

The first input of the dividing device 10 through group 8 of the 2-2-2I-ZILI circuits receives the N code from the subtractor 7. The permission to pass the N code through the group 8 of 2-2-2I-ZILI 8 circuits a signal coming from the output 22 of block 14 management According to the signal from the output 27 of the control unit 14 in the device 10, the code N is divided by the code N3. Dividing result equal to

enters through a group of 9 circuits 2-2-2I-j-ZIL And to the second input of the dividing device Y. The permission to pass the code NB produces a signal from the output 35 of the control unit 14.

The first input of the dividing device 10 receives the code N4 from the register 11 through a group of 8 circuits 2-2-2I-ZILI. Permission to pass the code generates a signal from the output 23 of control unit 14. The signal from the output 27 of the control unit 14 in the device 10 divides the code N4 by the code Ne. Dividing result equal to

... N4 „In Ki“ 1 V

I h 9 ™ 1 1

NeBpfi Vf

0 is proportional to the measured magnetic induction and does not depend on the material of the magnetic conductor with magnetic permeability fi // o and the mutual direction of the vectors of magnetic inductions B and. According to the signal 5 coming from the output 19 of the control unit 14, the measurement result is read by the counting device 12.

In the fourth switching cycle, when the signal appears at the output 43 of the decoder 52, the circuit OR 47 is triggered and outputs

0

five

0

0

five

the signal to the trigger input is 48. The latter goes into one state and gives the inhibitory potential to the circuit 45. As a result, the counting pulses from the generator 44 stop receiving counting pulses from the generator 44 pulses.

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION A digital magnetic induction meter comprising a Hall sensor, a current stabilizer, an induction coil, a voltage-code converter, a reversible counter, a dividing unit, a power source and a serially connected binary decimal decoder and digital reading device the code is connected to the output of a Hall sensor, the input of which is connected to the output of a current stabilizer, the output of the counting pulses of the voltage-code converter is connected to the counting input reversible counter, and the winding of the induction coil is connected to a power source, characterized in that, in order to improve the accuracy of measurements, two groups of circuits 2-2-2И-ЗИЛИ, two groups of circuits 2-2И-2ИЛИ, the comparison unit, register are entered into it The subtracting unit and the control unit, whose outputs from the first to the twentieth are respectively connected to the control input of the power source, to the first control input of the first group of circuits 2-2-2I-ZILI, to the second control input of the first group of circuits 2-2- 2-ZILI, with the third control input of the first group of circuits 2- 2-2И-ЗИЛИ, with a triggering input of a voltage-code converter with a control input of a binary-decimal decoder, with a setting input of a dividing unit, a division input of a dividing unit, with a subtraction input, with a control input and installation inputs of a deducting unit and reversing the counter, with the input of the reverse and with the control input of the reversible counter, with the first control input of the second group of circuits 2-2-2IL-ZILI, with the second control of the 5th input of the second group of circuits 2-2-2IL-ZILI, with the third control input of the second group of 2-2-2I-ZIL circuits , With an installation register input, a control input of the register, a first control 0 input of the first group of circuits 2-2I-2ILI and the second control input of the second group of circuits 2-2I-2ILI, with the second control input of the first group of circuits 2-2I-2ILI and the first control input of the second group of circuits 2-2I- 2ILI, the input of the control unit is connected to the output of the comparison unit, the output of the register is connected to the first information input of the first group 2-2-2И-ЗИЛИ, the second information input of which is connected to the output of the reading unit, the first and second information inputs of the second group of circuits 2-2 -2И-ЗИЛИ, the third information input of which is connected to the input of p gi5 Stra, the signal input of the binary coded decimal decoder and output divider, Tel'nykh unit having a first input connected to the output circuits of the second group 2-2-2I-Zili, the second input of divider Block 0 is connected to the output of the first group of 2-2-2I-ZILI circuits, the third information input of which is connected to the code output of the voltage-code converter and the first information inputs of the block 5 comparison of the first and second groups of 2-2IIL schemes, the second information input of the first and second groups of 2-2I-2ILI schemes and the comparison unit is connected to a code output, - the house of the reversible counter, the output of the first The 0 group of circuits 2-2I-2ILI is connected to the first information input of the subtractive unit, the second information input of which is connected to the output of the second group of elements 2-2I-2IL. five t LD rt h RSJS§ & $ fi $ U $ U.S SJ§33 § 3 cm I U.S 3