SU993179A1 - Teslameter - Google Patents

Description

(54) TESLAMETER

The invention relates to electrical measuring equipment and can be used in devices dp measuring the magnetic induction of a constant magnetic field. A time-pulsed teslameter with a ferromodulation transducer containing an excitation generator, a pulse shaper, a duty cycle detector, a meter, a counting pulse generator and a pulse counter is known, and the excitation generator is connected in series with the ferromodulation transducer and pulse shaper, one output of which is connected through a well detector to the meter, and the other output through the element And is connected to the pulse counter. A second pulse generator 13 is connected to the second input of the element. Its shortcomings are low accuracy. A teslameter is also known, containing a series-connected excitation generator, a ferromodulation converter, a band-pass filter, a scaling amplifier, an adder, a pulse shaper, and a recorder and a pulse generator, the second input of the adder is connected to the second output of the excitation generator 23. Its disadvantage is the low accuracy. The purpose of the invention is to improve the accuracy. The goal is achieved in that a teslameter containing series-connected excitation generator, ferromodulation converter, band-pass filter, scaling amplifier, adder, pulse shaper, as well as a recorder and a pulse generator, the second input of the adder is connected to the second the output of the excitation generator, the first trigger, a character trigger, four AND elements, a pulse counter, a pulse counter control unit, a digital-to-analog converter, and The second output of the excitation generator is connected to the trigger input and the first inputs of the first and second element I, the second inputs of which are connected to the output of the trigger and to the first input of the third element I, the second input of which is connected to the output of the pulse former, and you i turn through the fourth element And it is connected to the counting input of the Pulse Counter, the outputs of which are connected to the information inputs of the recorder and the input of the D / A converter, the control inputs of which are connected to the output of the sign trigger, the first the input of which is connected to the higher output of the pulse counter, and the second input to the output of the first element I and to the first input of the control unit of the counter, the first output of the pulse generator is connected to the second input of the fourth element I, the second output to the second input of the control unit of the counter, the third input of which is connected to the output of the preceding most significant bit of the pulse counter, and the outputs are connected to the inputs of the installation of the pulse counter, the output of the digital-to-analog converter is connected to the feedback input of the ferromodule transducer, the output of the second element And is connected to another control input of the register - torus.

In addition, the counter control unit contains the fifth, sixth and seventh elements And the second trigger, the first input of the counter control unit is connected to the first inputs of the fifth and sixth elements And the second trigger, the second input of the control unit is connected to the second and first inputs of the seventh element And to the second input of the fifth element And, the third input of which is connected to the output of the second trigger, the third input of the control unit of the counter through the seventh element And is connected to the second input of the sixth element And, the output of which connects jjGH to ervomu counter output control unit, the second output of which is connected to the output of the fifth AND gate and a second input of the second flip-flop.

FIG. 1 shows a teslameter circuit; FIG. 2 shows timing charts explaining his work; in fig. 3 is a diagram of a meter control unit.

The teslameter contains excitation generator 1, ferromodulation converter 2, band-pass filter 3, scaling amplifier 4, adder 5, pulse former b, elements 7 and 8 AND, trigger 9, element 10, counter 11 pulses, element 12, pulse 13 , block 14 control counter, the recorder 15, digital-to-analog converter (DAC) 16, the trigger 17 characters. In addition, the counter control unit 14 contains AND elements 18 and 19, trigger 20, and AND element 21.

The work of the teslameter is as follows.

The ferromodulation converter 2, excited by the current from excitation generator 1, is affected by the difference between the measured and compensatory magnetic induction B – B.

5 The second harmonic voltage selected by the bandpass filter 3 is scaled through amplifier, 4 is fed to adder 5, to another input of which the first harmonic signal U i is fed from excitation generator 1 at a time relative to the second harmonic signal (Fig. 2a (- -). A shaper of 6 pulses converts a monotonically varying sum total signal of the first and

the second harmonics into pulses with steep edges 0 (Fig. 26). Pulses (j are also fed to trigger 9, the output signal of which (Fig. 25) serves to divide the counting processes in time (corresponds to the positive polarity Uj), display and setting the counter to the initial state equal to N, / 2, where is the 5 count of the counter.The resolution signal, the UMM indication (Fig. 2) is formed at the output of the And 7 element and is fed to the corresponding input of the recorder 15. The installation permission signal

0 counter to initial state (J

(Fig. 2e14, which is formed at the output of the element And 8, is fed simultaneously to the inputs of the elements And 18 and 21 and to the trigger 20 (Fig. 3). The element And

59 18 only passes one pulse

from the generator there are 13 pulses and, 5 (Fig. 2i.) which sets the highest decade of the pulse counter 11 pulses to zero, and the remaining decades to nine. Through the element And 19 and the element And 21 (Fig. 3) pulse generator 13 (Fig. 1) sets

the high decade of the counter 11 pulses to state four (Fig. 2k); 5 upon reaching which the pulse U (Fig. 2A) at the output of the preceding most significant bit of the pulse counter (Fig. 1) closes the AND 19 element (Fig. 3). Thus, the counter control unit 0 14 sets the pulse counter 11 to a state corresponding to half of its capacity. The frequency of the pulse generator 13 is selected from the following values.

To ensure a linear conversion and equivalence of the readings of the counter 11 pulses of the difference in time intervals at the output of the pulse builder 6. it is necessary that in the time period Tg equal to the excitation frequency period of the ferromodulation converter 2, the number of counting pulses is stored (Fig. 2) equal to the capacitance of the receiver, i.e. 1л.Ь: 11 where f is the excitation frequency of the ferro-modulation transformation of body 2; f is the pulse frequency of the generator. ra 13 pulses; T is the period of the pulses of the generator of 13 pulses. The induction value of the measured magnetic field is defined as B G, (n -4) -, (3 where Gg is the temporal sensitivity of the ferromodulation transducer 2, TL / s, h is the number of pulses and (Figure 2 transmitted from the generator 13 pulse through the element 12 to the second input of which a pulse Ug arrives (Fig. 2 to the pulse counter 11. pulses. ag. From the formula (3J it can be seen that if Nru n -2 °. has a minus sign and the pulses counter 11 has to be read in reverse code. To notify the registrar 15 and the DAC 16, a trigger 17 characters is inserted, which is included between the high-order the pulley 11 and the corresponding inputs of the recorder 15 and the DAC 16, and before each measurement and registration cycle the character trigger 17 is set to the initial state by an impulse and (Fig.) from the pulses of the element 7. 7. NCM then V O. If n N At n J - at the moment of transition of the most significant discharge of the pulse counter 11 from the state one to the state zero, the trigger 17 of the sign is activated and the positive value of the measured constant magnetic induction is fixed. As a result of introducing a trigger, a sign trigger, four AND elements, a pulse counter, a counter control unit, a pulse of a digital-analog converter converter, the measurement accuracy is improved. invention 1. A teslameter containing successively connected excitation generator, ferromodulation converter, band-pass filter, scaling amplifier, adder, pulse driver, as well as a recorder and a pulse generator, the second input of the adder is connected to the second output of the excitation generator, different by the fact that, in order to increase the accuracy, the first trigger, the character trigger, four AND elements, the pulse counter, the counter control unit of 1 pulses, are introduced into it; a digital-analog converter, the second output of the excitation generator is connected to the trigger input and the first inputs of the first and second elements And, the second inputs of which are connected to the output of the trigger and to the first input of the third element And, the second input of which is connected to the output of the pulse driver, and the output through the fourth element I is connected to the counting input of the pulse counter, the outputs of which are connected to the information inputs of the register, the rator and the inputs of the digital-to-analog converter, the control inputs of which are united with the trigger output of the sign, the first inlet of which is connected to the high-end output of the pulse counter, and the second input is connected to the output of the first And element and to the first input of the counter control unit, the first output of the pulse generator is connected to the second input of the fourth And element, the second the output is with the second input of the counter control unit, the third input of which is connected to the output of the previous high-order pulse counter, and the outputs are connected to the inputs of the pulse counter installation, the output of the digital-to-analog converter It is connected to the feedback input of the ferromodulation converter, the output of the second element I is connected to another control input of the recorder. 2. Teslameter according to claim 1, that the meter control unit contains the fifth, sixth, seventh And elements and the second trigger, and the first input of the meter control block is connected to the first inputs of the fifth and sixth And elements and the second trigger, the second input of the counter control unit is connected to the second and first inputs of the seventh And element, and to the second input of the fifth And element, the third input of which is connected to the output of the second trigger, the third input of the counter control unit through the seventh And element ment-I, the output of which is connected to the first output of the control unit of the counter, the second output of which is connected to the output of the fifth ele- ment M (Mria I and the input of the second trig Sources of information, ....., taken into account during the examination 1. Semenov NM, Yakovlev NI - h-V.-. ««. -I fft: f JOJ1KS S3Л Kl # Digital ferrohend magnetometers. L., Energie, 1978, p. 98. 2. Semenov N. M. Yakovlev, NI Digital Ferrozond Magnetometers, iJUBbie Ferrozond Magnetograph, Energie, 1978, p. 105

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Claims (2)

Claim 1. A teslameter containing a series-connected excitation generator, a ferromodulation converter, a bandpass filter, a scaling amplifier, an adder, a pulse shaper, and a recorder and a pulse generator, the second adder input is connected to the second output of the excitation generator, characterized in that, for the purpose of improving accuracy, the first trigger, a sign trigger, four elements And, a pulse counter, a pulse counter control unit are introduced into it; a digital-analog converter, the second output of the excitation generator connected to the input of the trigger and the first inputs of the first and second elements AND, the second inputs of which are connected to the output of the trigger and the first input of the third element And, the second input of which is connected to the output of the pulse shaper, and the output through the fourth element And is connected to the counting input of the pulse counter, to the outputs of the discharges of which are connected the information inputs of the recorder and the inputs of the digital-analog converter, the control inputs of which are connected with the output of the sign trigger, the first input of which is connected to the output of the highest bit of the pulse counter, and the second input - to the output of the first AI element to the first input of the counter control unit, the first output of the pulse generator is connected to the second input of the fourth element And, the second output - to the second the input of the counter control unit, the third input of which is connected to the output of the pulse counter preceding the senior discharge, and the outputs are connected to the pulse counter installation inputs, the output of the digital-to-analog converter is connected to .obratnoy communication house ferromodulyatsionnogo converter, the output of the second element, cops and connected to another control input of the recorder. 2. Teslameter in π. 1, wherein the counter control unit comprises the fifth, sixth, seventh AND elements and a second trigger, the first input of the counter control unit being connected to the first inputs of the fifth and sixth elements Y and the second trigger, the second input of the counter control unit connected to the second and first input of the seventh element And and to the second input of the fifth element And, the third input of which is connected to the output of the second trigger, the third input of the counter control unit through the seventh element And is connected to the second input of the sixth element And, the output of which th first output connected to the counter of the control unit, the second output koto7 cerned connected to the output of the fifth AND gate and a second input of the second flip-flop.