SU1264318A1 - Device for generating calibration signal - Google Patents

Abstract

The device relates to a measurement technique. It can be used for calibration and calibration of sawtooth voltage non-linearity meters. The aim of the invention is to expand the functionality of the device. In the device containing the source of constant voltage, I integrate

Description

phi 1

RC circuit 2, to achieve the goal, a generator of 3 sinusoidal signals, an attenuator 4, comparators 5, 6, 7, element I 8, sources 9, 10 of the reference voltage, buffer amplifiers P, 12, switch 13, adder 14, key 15, control block 16. The goal is achieved by generating a signal with disconnections from a linear signal of different signs, as well as a calibration signal of small dpi126

18

telnosti. The control unit 16 may be made on the basis of microprocessor technology or a computer line of the Spark 22B type. The device allows to form a signal with nonlinearity coefficients from hundredths of a percent to 100%, absolute deviations DT, or percent fractions of a percent to 10%, both positive and negative. 1 hp f-ly, 3 ill.

  one -

The invention relates to a measuring technique and can be used in the calibration and calibration of measuring parameters of non-linearity parameters of a sawtooth voltage,

The purpose of the invention is to expand the functionality of the device by generating a calibration signal with disconnections from a linear signal of different signs, as well as a calibration signal of short duration.

Figure 1 shows the block diagram of the proposed device; 2 are diagrams explaining his work; FIG. 3 shows the working section of a formulated calibration signal.

The device contains a source of constant voltage I, integrating an RC circuit 2, a generator of 3 sinusoidal signals, an attenuator 4, the first 5, the second 6 and the third 7 comparators, the element 8, the first 9 and the second 10 sources of reference voltage, the first 11 and second 12 buffer amplifiers, switch 13, adder 14, switch 15 and control unit 16, the generator 3 of sinusoidal signals being connected to the input of the integrating RC circuit 2 and the input of the attenuator 4, the output of which is connected to the input of the first buffer amplifier 11, also to the first inputs of the second 6 and three Next, 7 comparators, the second inputs of which are connected respectively to the outputs of the first 9 and second 10 sources of reference voltage, the output of the integrating RC circuit 2 is connected to the first, the input of the first comparator

5, the second input of which is connected to the point of zero potential, the inverse output of the second 6 and the direct output of the third 7 comparators are connected respectively to the first and second inputs of the AND element 8, the third input of which is connected to the first output of the switch 13, and the output is connected to the control input The plug 15, the first input of which is connected to the output of the first buffer amplifier 11, the second input to the second output of the switch 13, and the output to the first input of the adder 14, the second input of which is connected to the output of the constant voltage source 1, and d - to the input of the second buffer amplifier 12, the output of which is the output of the device, the first input of the switch 13 is connected to the inverse output of the first comparator 5, the second input to the direct output of the first comparator 5, the third input to the output of the second source 10 of the reference voltage and the fourth input is with the output of the first source 9 of the reference voltage, which controls the input buses of the generator 3 sinusoidal signals, the attenuator 4, the first 9 and the second 10 sources of the reference for the voltage, the constant voltage source 1 and the switch 13 not correspondingly with the first, second, third, fourth, fifth, and sixth control output tires of the control unit 16.

The device works as follows.

A sinusoidal signal generated by a sinusoidal generator 3

The signal (Fig. 2a) is fed to the inputs of the attenuator 4 and the integrating RC-uepi 2. The signal frequencies are determined by the code supplied to the input control bus of the generator 3 from the first control output bus of the control unit 16. At the output of the attenuator 4, the signal coincides in phase with the output signal of the generator, and its amplitude is inversely proportional to the control code supplied to the input control bus of the attenuator 4 from the second output control bus of control unit I6. From the output of the integrating circuit 2, the signal having a phase shift (-If / 2) relative to the input signal (Fig.26) is fed to the first input of the first comparator 5, the second input of which is connected to the point of zero potential. As a result, at the forward output of the first comparator 5 (Fig. 2b), the signal of a logical unit corresponds to the phase interval of the signal generator 3 pa 3 (;; + 2nn, + 21Gp), and the logical zero - phase interval (- - -tZiTn,

| - +2 | Гп)., ± 1, ± 2 ..... At the inverse output is the opposite signal.

If switch 13 is in the first position, then the signal from the inverse output of the first comparator 5 comes from the first input to the output of the first group and further. To the third input of element I. If the switch 13 is in the second position, then to the third input of the element I signal the signal from the direct output of the first comparator 5 through the second input and output of the first group. The position of the switch 13 is determined by the signals received by 1 mi on its input control bus from the sixth control output bus of the control unit 16.

The signal from the output of the attenuator 4 is supplied to the first input of the key 15 through the first buffer amplifier 11, as well as to the first inputs of the second 6 and third 7 comparators. The operation levels of the comparators are determined by the constant voltages supplied to the second inputs of the second 6 and third 7 comparators, respectively, from the first 9 and second 10 sources of reference voltage. The voltages of the first 9 and second 10 voltage sources are determined by the control codes supplied to their control input buses from the third and fourth control output buses of the control unit 16, respectively. Thus, the signal of the logical unit at the inverse output of the second comparator corresponds to the phase intervals (2 "over (, + 2Sn), (-0:, + + 21 | n), 2 7 () 3. 3 at the direct output of the second comparator - phase interval. (, (ft-ofj) + 21Gp), geo,

 arcsin -; and arcsin is; U ,, Uj -2-m

voltage according to the first 6

and the second 7 sources of reference voltage, and - the amplitude of the signal at the output of the attenuator 4. From the inverse output of the second comparator 6 (FIG. 2d and the direct output of the third comparator 7 (4ds.2d), the logical signals go to the first and second inputs of the And 8. If the switch 13 is in the first position, then the signal of the logical unit at the output of the element And 8 (Fig. 2e) corresponds to a sinusoid section in the phase interval (s + 2i-n, ",) (fig. 3 and if in the second position, then t ((,) + 21Гn, (r - (, j) + 2iTn. The signal from the output of the element And 8 goes to the control input d key 15. If this signal is a logical unit, then the signal from the first key input goes to the key 13 input, and from the second input if the logical zero. In the first position of the switch 13 to the second key input 15 through the first input and the second switch group 13, the voltage of the second source 10 of the reference voltage is supplied, and in the second position, the first source of the reference voltage 9. As a result of the operation of the switch 15, the signal at its output has the form of sawtooth pulses, increasing (first position of the switch 13) or falling (second field Shifting the switch 13) the area of which is a sinusoidal segment (Fig. 2g). In the pauses between the sawtooth pulses, the signal has a constant level and (for a linearly incident voltage) or U (for a linearly increasing voltage).

Claims (2)

This signal is added in the adder 14 to a constant voltage source 1 signal, which sets the constant component of the output signal under the action of a control signal from the fourth control output bus of control unit 16 to the input control bus of the constant voltage source 1. From the output of the adder 14, the signal through the second buffer amplifier 12. enters the output of the device. Control unit 16 is a specialized control computing device. By controlling the attenuation of the attenuator 4, the constant voltages of the first 9 and second 10 reference sources and the constant voltage source 1 by the position of the switch 13, the control unit provides pulses of both linearly increasing and linearly falling voltage, linear section which has calibrated nonlinearity parameters, since it is a sinusoid section, the quality of which, in turn, can be easily estimated using known spectral methods, and the beginning and end of the working code are constant for This signal and can be verified, for example, by compensation methods. As a result, the nonlinearity parameters are uniquely associated with the parameters set by the control unit 16. Two algorithms of operation of the control unit 16 are possible. According to the first algorithm, according to the set values of the frequencies f of the generator signal 3, attenuation A of the attenuator 4, U |, Uj, and voltage Unocr of a constant voltage source, the control unit calculates the values of the initial level U and the amplitude and y, (or the final level U a) the output signal, the nonlinearity coefficient Kp, the maximum absolute deviation U, the pulse duration T and its repetition period T and indicate the calculated values. According to the second algorithm, according to the parameters U (UK) and (UK) K5 (b) entered into the control unit 16, t computed sary value f, U, and nof. the corresponding control codes are issued for the input control; Actuator buses (generator of 3 sinusoidal signals, attenuator 4, first 9 and second 10 reference sources, constant voltage source 1 NIN and switch 13). In the case of a discrete implementation of the control block 16 and the control circuits of the executing devices, it is impossible to accurately set the calculated values of f, and, A,. therefore, after the installation of the approximate values, it is advisable to calculate according to the first algorithm and display the refined parameters U, U (U), K ,, D „, T and T. The device allows you to receive signals with calibrated parameters that have maximum absolute deviations of different signs, different in absolute value. It is possible to move the moments of maximum deviations along the axis of the belt within the pulse duration. Due to the presence of a sinusoid stretched very close to the linear portion in the vicinity of the zero phase, very small nonlinearity values can be obtained. In most cases, to simplify the control unit 16, it is advisable to limit the generation of signals at / and / / Ui /, / o, /. The first algorithm. Baseline data for the calculation: f. A, U, U :, post also UT is the amplitude of the sinusoidal signal at the output of generator 3 (constant for each specific device); stress increasing (falling). 1.T / 2. / - arcsin (Ui A / Ur) 3.s (for linearly applied and, th, and thawing voltage (for linearly U, (linearly incident) 5.U, Uo + Un. -.. -D -.sinoix) 6.y. U sin arccos () J sinu fSin. - -arccos C- -) j where rS arcsin (U, A / Up), ui, the maximum values of the modules, respectively, positive and negative absolute deviations 7.Kr (1-co8og) -100% second algorithm. Baseline data for the calculation: K (ylid) U ,, Uj (or Uj), c, voltage increasing (falling). 1. 6t arccos (1-Kjj), Determined by numerically solving the transcendental equation 7 (item 6 of the first algorithm) for a given A. 2. and, and „/ 2 (,; / 2 3. А А. f S т 5 .Т 6.,., (For linearly increasing voltage and, -and, (for linearly falling voltage) 7 If it is necessary to refine, calculations are carried out according to the first algorithm. Control unit 16 can be executed on the basis of microprocessor technology or Spark 22B computer line. Digital-analogue converters of the appropriate size are used as sources of reference and constant voltages. highly stable voltage source. The calibration signal shaping device allows Signal with nonlinearity coefficients from hundredths of a percent to 100%, absolute deviations from thousandths of a percent to 10%, both positive and negative. The device is also applicable for generating a signal with monotonic nonlinearity. Ments of maxima and minima of the deviation within the time interval corresponding to the working stroke, allows to study the dynamic characteristics of the meters. Claim 1. A calibration signal generating device comprising a constant voltage source and an integrating KS circuit, characterized in that, in order to extend the functionality, a generator of the sine signal, the attenuator, the first, the second and the third are additionally introduced into it. comparators, And elements, the first and second sources of the reference voltage, the first and second buffer amplifiers, a switch, an adder, a switch and a control unit, the output of the sinusoidal signal generator being connected to the input 18 in a RC circuit and an attenuator input, the output of which is connected to the input of the first buffer amplifier, as well as to the first inputs of the second and third comparators, the second inputs of which are connected respectively to the outputs of the first and second reference voltage sources, are connected to the first the input of the first comparator, the second input of which is connected to the common bus, the inverse output of the second and the direct output of the third comparator are connected, respectively, to the first and second inputs of the element I, the third input of which is connected the first output of the key is connected to the output of the first buffer amplifier, the second input is connected to the second output of the switch, and the output is connected to the first input of the adder, the second input of which is connected to the output of the constant source voltage, and the output to the input of the second buffer amplifier, the output of which is the output of the device, the first input of the switch is connected to the inverse output of the first comparator, the second input to the direct output of the first comparator., the third input of the switch with the single input of the second source of the reference voltage, and the fourth input - with vn. - the course of the first source of the reference voltage, the control input busses of the sinusoidal signal generator, attenuator, the first and second sources of the reference voltage, the constant voltage source connected to the first, second, third, fourth, fifth, and sixth control output buses of the control unit, respectively. h 2. A device according to claim 1, characterized in that the switch comprises two interlocked three-buttons. clock groups, the switching contacts of the first and second groups are connected respectively to the first and second outputs of the switch, the breakers and the closing contacts of the first group are connected respectively to the opening and closing inputs of the switch, and the first and second switches from the second group to the third and fourth inputs of the switch respectively.  X / V   j 6 in / U / U fi.Z