SU1187114A1 - Digital magnetic flux meter - Google Patents

Abstract

A DIGITAL MAGNETIC FLOW METER containing an inductive primary transducer, first and second keys, a switching unit, first and second triggers, a pulse counter, a decoder, a digital indicator, a first and second one-shot and a series-connected quartz pulse generator, and a frequency divider, characterized in that In order to increase the measurement accuracy, a voltage-frequency converter, first and second buffer registers, a third one-shot and four elements, are additionally introduced into it; The induction primary converter, the first key, the voltage-frequency converter and the second key are subsequently connected, the first output of the second key is connected to the subtractive, and the second output is connected to the summing inputs of the pulse counter, the output of the latter is connected to the D inputs to enter information of the first and second buffer registers the output of the first buffer register is connected to the D-BXO input of the pulse counter information, and the output of the second buffer register is connected via a decoder to the input of a digital indicator, the output of which is connected It is connected to the first control input of the first key, and the output of the frequency divider is connected to the series-connected first and second. one-shot and first inputs of the first and second elements I, the output of the switching unit is connected to the dynamic C-inputs of the first and second trigger 1, and the direct O-VBPKOD of the first trigger is connected to the input of the third single-oscillator, the second control input of the first and the control input the second key, and the inverse Q-output of the first trigger with the second inputs of the first and second cops And and the V-input of the control factor E.dk with the frequency divider recalculation fraction, the output of the first one-oscillator is connected to the second input of the third And, the output of the second one-shot - to the first input of the fourth element I and the R-input of the 4 O device of the first trigger, and the output of the third one-shot - to the R-input of the O setting of the frequency divider and C-input of the pulse counter information, This direct Q-output of the second trigger is connected to the third input of the second, and the inverse 0 output to the third input of the first and second inputs of the fourth And elements, the outputs of the first and second And elements are connected respectively to the C-inputs of the information setting, the first and second buffer registers s, treteklyuchey output, the first input of the third element

Description

The first element And to the R-input O of the second trigger, and the installation of the true element And to the R-input of the statutory counter in 1777114 in the O pulse counter.

one

The invention relates to electrical measuring equipment and can be used to measure the magnetic flux of permanent magnets.

The purpose of the invention is to increase the measurement accuracy by reducing the effect of zero drift during the measurement time.

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

The circuit contains a series-connected induction primary transducer 1, primary key 2, voltage-frequency converter 3 second key 4, pulse counter 5, first 6 and second 7 buffer registers connected to the output of pulse counter 5, depressor 8, indicator containing digital indication 9 of the measurement result, a block 10 of the mark, a digital indication of the 11 mark, a series-connected crystal oscillator 12 pulses, a frequency divider 13, a first 14 and a second 15 one-oscillators, and a switch 16, through the first 17 and second 18 triggers connected to the third one-shot 19, first 20, second 21, third 22, and fourth 23 elements I.

The device works as follows.

In the initial state, the signal at the output of the inductive primary converter 1 is zero, the first key 2 is open, the pulse counter 5 is in the zero state, the switching unit 16 is open, the first 17 and second 18 triggers are in the zero state. A quartz oscillator 12 pulses forms a sequence of pulses of a stable frequency, which is fed to the C input of the frequency divider 13, while the V-input controlling the conversion factor of the latter receives a single signal from the inverse d output

first trigger 17, therefore, at the output of the frequency divider 13, a sequence of pulses is formed with a period T edl / 2, where the time is measured. nor, pre-selected by the operator. On the falling edge of the pulse at the output of the frequency divider 13, the first one-shot 14 is excited, on the falling edge of the output signal of which the second one-shot, the torus 15, is triggered. Thus, a sequence of three pulses arises at the end of the time interval T / 2, the first of which is output the frequency divider 13 through the first element And 20 enters the C-input installation information of the first buffer register 6, the second output of the first one-shot 14 through the third element And 22 enters the R-input of the installation in O, the second trigger 18, and the third - from the output of the second single-shot 15 arrives at the R-input of the installation in O of the first trigger 17 and through the fourth element I 23 - to the R-input of the installation at zero of the pulse counter 5. The second element of And 21 is blocked by a zero signal from the output of the second trigger 18. The sign extracting unit determines the polarity of the measured flux, depending on which the first 2, according to the signal at the second control input from the Q output of the first trigger 1 7, connects the output of the inductive primary converter 1 to the input of the voltage-frequency converter 3 positive Does the negative direction and is turned sootvetstvuyuidy sign indicating digital converter 11. The output frequency of the three voltage-to-frequency characteristic determined by the static type

F3 (Ug, K3UgJt) H b (t), where FjCUgx) is the output frequency;

Ke is the proportionality coefficient, Uex (t) is the signal at the input; 3 b (t) is the frequency at the output of the voltage-frequency converter at the zero signal at the inlet. The change in b (t) is determined by the drift of the zero voltage-frequency converter 3. Since the first trigger 17 is in the zero state, the first key 2 is open, and the second key A connects the output-converter 3 voltage frequency to the subtracting input of the counter 5 pulses. Thus, at the end of the time interval T, /, the state of the pulse counter 5 will be proportional to the integral of the value b (t) characterizing the drift zero of the voltage-to-frequency converter 3. N (V./2) - b (t) dt. The state of the counter 5 pulses N (T / 2) is written to the first buffer register 6 by the first pulse, after which the third pulse is set to the O counter 5 pulses. Next, the process repeats. In order to measure the magnetic flux, the test sample is placed in the working area of the inductive primary transducer 1, the sign extracting unit 10 is triggered and the switching unit 16 is closed, but this causes the first 17 and second triggers 18 to switch, as the latter are switched to a single state on the rear the front of the pulse that is formed when the switching unit 16 is opened. When a test specimen is removed from the working zone of the inductive primary converter 1, the switching unit 16 is opened, which causes the first 17 and second 18 flip-flops to be switched to one state. In this case, the first switch 2, using the signal at the second control input, connects the induction of the primary transducer 1 in the direction corresponding to the measured sample of polarity to the input of the voltage-frequency converter 3, the second switch 4 connects the output of the latter to the summing input of the pulse counter 5. On the pulse front, the one-shot 144 19 is driven at the direct p-output of the first trigger 17, the output pulse of which is set to a frequency divider 1J, and the pulse counter 5 is in the state stored in the first buffer register 6. To the V-input of the coefficient control recalculation of the frequency divider 13 receives a zero signal from the inverse Q-output of the first flip-flop 17, so the conversion factor is doubled and the next pulse at the output of the frequency divider 13 rises after a time interval Tcz. This time is chosen to be obviously greater than the maximum pulse duration at the output of the inductive primary converter 1. During the time interval T, J | the output pulses of the voltage-frequency converter 3 are summed by a pulse counter 5. When a pulse appears at the output of the frequency divider 13, i.e. at the end of the gap first. 20, the second 21 and third 22 elements And will be blocked by a zero signal from the inverse Q-output of the first trigger 17, the output pulse of the first one-oscillator 14 will start the second one-oscillator 15, the output pulse of which will set the first element 23 to zero blocked by the signal from the inverse Q-output of the second trigger 18. After switching the first trigger 17, the first key 2 turns off the inductive primary converter 1 from the voltage-frequency converter 3, the second key connects to the counting subtracting input 5 and the pulse output transducer 3-frequency voltage on V-input control frequency conversion coefficient divider 13 post paet unit with inverse Q-output of the first flip-flop 17, so the next pulse at the output of frequency divider 13 at a time interval Vits Tj ,. During this time interval, the output frequency of the voltage-frequency converter 3 is determined by the value of b (t). At the end of the indicated time interval, the state of the pulse counter 5 is determined by the algebraic sum N (b (t) U, (t) + b (t) d 1 .. J 1 -1 (j:) dt.

The impulse from the output of the frequency divider 13 through the second element I 21, on the second and third inputs of which there are single signals from the direct Q output of the second trigger 18 and inI BepcHoro the Q output of the first trigger 17, goes to the C input of setting the information of the second buffer register 7, with the result that the latter is established in the state N (21;). On the trailing edge of the pulse from the output of the splitter 13 frequency produces a pulse

the first one-shot 14, which through the third element I 22 is set to O the second trigger 18, after which the output signal of the second one-shot 15 through the fourth element I 23 sets the counter 5 pulses to the O. After that, the device is in the initial state and is ready for the next measurement, and the result of the measurement is displayed on the digital display of the result 9 and the sign 10.

Claims (1)

A DIGITAL MAGNETIC FLOW METER, comprising an induction primary converter, first and second keys, a switching unit, first and second triggers, a pulse counter, a decoder, a digital inductor, a first and second one-shot oscillator and a series-connected quartz pulse generator and a frequency divider, characterized in that, in order to increase the accuracy of measurement, a voltage-frequency converter, first and second buffer registers, a third one-shot and four AND elements are additionally introduced into it; the induction primary converter, the first switch, the voltage-frequency converter and the second switch are connected separately, the first output of the second switch is connected to the subtractor, and the second output is to the summing inputs of the pulse counter, the output of the latter is connected to the D-inputs of the information input of the first and second buffer registers, the output of the first buffer register is connected to the D-input of the pulse counter information input, and the output of the second buffer register is connected through a decoder to the input of a digital indicator, the output of which is connected to the first to the first input of the first key, and the output of the frequency divider is connected to the first and second single vibrators and the first inputs of the first and second elements AND, the output of the switching unit is connected to the dynamic C-inputs of the installation of 1 of the first and second triggers, and the direct Q-code of the first trigger connected to the input of the third one-shot, shch, the second control input of the first and control input of the second key, and the inverse Q-output of the first trigger with the second inputs of the first and second keys, the first input of the third ele I and V — input of the control factor of the frequency divider, the output of the first one-shot connected to the second input of the third element And, the output of the second one-shot to the first input of the fourth element And the R-input of the installation to 0 of the first trigger, and the output of the third one-shot to R -the input of the setting to 0 of the frequency divider and the C-input of setting information of the pulse counter, while the direct Q-output of the second trigger is connected to the third input of the second, and the inverse 0-output to the third input of the first and second input of the fourth elements rows of first and second AND gates respectively connected to the C-input setting information, the first and second buffer registers, output third · SU .1187114 of the first element And - to the R-input of the installation of the second element And - to the R-input, the charter is 0 ^{m of the} second trigger, and the output of the control unit is 0 of the pulse counter.