RU2557340C1 - Oscillographic measuring device of amplitude characteristics of electric signals - Google Patents

Abstract

FIELD: instrumentation.SUBSTANCE: invention relates to instrumentation, and namely to measuring devices of amplitude characteristics. Oscillographic measuring device of amplitude characteristics of electric signals consists of an oscillograph 1, the first and the second reference voltage sources 2 and 3, the first switch 4, a voltage difference meter 5, the first and the second smoothly adjustable delay lines 6 and 7, the second switch 8, a zone level formation unit 9, a zone pulse generator 10, a voltage equality indicator 11, a control unit 12, the first coupling capacitor 13, the third and the fourth reference voltage sources 14 and 15, the third switch 16, an additional voltage difference meter 17, an additional coupling capacitor 18, the first and the second coupling resistors 19 and 20, the fifth and the sixth reference voltage sources 21 and 22, the fourth switch 23, the third voltage difference meter 24, the third coupling capacitor 25, the third coupling resistor 26, the seventh and the eighth reference voltage sources 27 and 28, the fifth switch 29, the fourth voltage difference meter 30, the fourth coupling capacitor 31, the fourth coupling resistor 32, the fifth coupling resistor 33 and sixth coupling resistor 34. The device ensures Rx measurement according to two-cascade option, at that cascades out of different segments are used, as well as possibility to measure Rx according the four-cascade option; when two-cascade meters interacting under modes of mutual compensation of the undesirable effects of the reference voltage sources at the input terminals of the meter. The ratios ensuring the mutual compensation conditions are determined.EFFECT: increased accuracy and authenticity of the amplitude measurements.1 tbl, 5 dwg

Description

The present invention relates to electrical engineering and can be used in the development of high-precision high-speed oscillographic meters of the nanosecond and subnanosecond ranges and testers for testing high-speed integrated circuits.

According to the main copyright certificate No. 599217, class. G01R 13/30, claimed 06/22/79, an oscilloscope measuring the amplitude characteristics of electrical signals (meter) is known, containing an oscilloscope, the first input of which is connected to the first input terminal, the first output to the first input of the zone leveling unit, the second output to the first input of the zone pulse generator, the output of which is connected to the input of the illumination of the oscilloscope and the second input of the unit for forming zone levels, and the second input is to the third output of the control unit, the first output of which is connected to the third input of the unit for forming zone levels, the second output is with the control input of the second switch, and the fourth output is with the control input of the first switch, the output of which is connected to the first output of the coupling capacitor and the second input of the oscilloscope, and the first and second inputs are to the first outputs of the first and second voltage sources, second outputs which are connected to the inputs of the voltage difference meter, and the inputs to the second input terminal and the second output of the coupling capacitor, the inputs of the first and second continuously adjustable delay lines connected to the synchronization input ation meter, and the outputs - the first and second inputs of the second switch, whose output is connected to the input of the oscilloscope synchronization, and the first and second outputs of the block forming zones levels are connected to inputs of equality indicator strains [1].

The disadvantage of the meter is the appearance of errors in amplitude measurements due to:

- the dependence of the error of the amplitude measurements on the value of the active component in the output resistance of the source of the studied signals (Rx);

This disadvantage is due to the fact that with a varying value of Rx and the commensurability of the values of Rx and the input impedance of the meter (Rin), the division ratio of the divider formed at the input of the meter is variable, which leads to additional errors in the conduct of amplitude measurements.

Thus, the use of this meter circuit can be effective either with a known and constant value of Rx, or with Rx << Rin.

- the impossibility of measuring the value of Rx in a compensation way with a single-stage meter circuit (one stage includes two adjustable sources of reference voltages, a voltage difference meter, a switch, and RC communication elements);

- the influence of sources of reference voltages on the source of the studied signals;

This drawback is due to the fact that the sources of reference voltages are connected in series with the source of the signals under study and, when the values of Rx and Rin are comparable, the voltage drops at Rx can be comparable with the values of the reference voltages, which can lead to malfunctions of the device under study.

- the impossibility of calculating the energy characteristics of the studied signals, since for these calculations, along with information about the amplitude of the studied signals, information on the value of Rx is necessary.

In order to improve the accuracy of amplitude measurements by reducing these errors and eliminating these drawbacks, the oscillographic meter of the amplitude characteristics of electrical signals according to the additional invention, ed. St. No. 815641 is equipped with a third and fourth voltage reference sources, an additional voltage difference meter, a third switch, two communication resistors and an additional communication capacitor, the first output of which is connected to the second input of the oscilloscope, the first output of the second communication resistor and the output of the third switch, and the second output to the output of the first switch, the first output of the first communication resistor and the inputs of the third and fourth sources of reference voltage, the second outputs of which are connected to the inputs voltage difference meter ceiling elements, while the first outputs of the first and second inputs of the third switch, whose control input is connected to the fifth output of the control unit, wherein the second terminals of the resistor connected to the first input of an oscilloscope [2].

This meter provides:

- measurements of the value of Rx in any area of the investigated periodic digital signal in a compensation way due to the non-identical conditions in the input circuits of the meter for each of the pairs of reference voltage sources;

- reducing the effect of changes in the value of Rx on the error of amplitude measurements due to the inclusion of these changes when performing calculations on derived ratios;

- the ability to calculate the energy characteristics of the studied signals based on the data of amplitude measurements and measurements of Rx.

The disadvantage of this meter is the appearance of amplitude measurement errors due to the influence of reference voltage sources on the source of the studied signals when measuring Rx, which leads to a decrease in the accuracy and reliability of the measurement results of Rx.

This effect is due to the fact that a two-stage meter circuit can provide only one-sided compensation for the effects of voltage drop differences between two pairs of voltage reference sources.

When measuring Rx, compensation is made at the input of the oscilloscope, and the input terminals of the meter (and, therefore, the output of the device under study) are affected by the difference in voltage drops between two pairs of reference voltage sources.

The influence of sources of reference voltages on the source of the studied signals during amplitude measurements can disrupt the operation of the source of the studied signals, distort the shape of the studied signals and, accordingly, reduce the accuracy and reliability of the measurement results.

The aim of the invention according to published application No. 2012113266 of March 30, 2012 is to increase the accuracy and reliability of amplitude measurements due to eliminating the influence of sources of reference voltages on the source of the studied signals when measuring Rx.

This goal is achieved by the fact that the oscilloscope measuring the amplitude characteristics of electrical signals according to the published application for invention No. 2012113266 dated March 30, 2012, is equipped with a fifth and sixth voltage reference sources, a third voltage difference meter, a fourth switch, a third coupling resistor, and a third coupling capacitor, seventh and eighth reference voltage sources, fourth voltage difference meter, fifth switch, fourth coupling resistor, fourth coupling capacitor, with this, the first terminal of the fourth coupling capacitor is connected to the second terminal of the third coupling capacitor, the first terminal of the fourth coupling resistor, the output of the fifth switch and the inputs of the fifth and sixth voltage reference sources, the second outputs of which are connected to the inputs of the third voltage difference meter, and the first outputs to the first and the second inputs of the fourth switch, the control input of which is connected to the sixth output of the control unit, and the second terminals of the third and fourth communication resistors are connected to the first input ohm of the oscilloscope, and the first output of the third communication resistor is connected to the first output of the third communication capacitor, the second output of the first communication capacitor and the output of the fourth switch, along with this the second output of the fourth communication capacitor is connected to the second terminal of the meter and the inputs of the seventh and eighth reference voltage sources, the second the outputs of which are connected to the inputs of the fourth voltage difference meter, and the first outputs are connected to the first and second inputs of the fifth switch, the control input of which is connected to the seventh th output control unit [4].

This meter provides:

- measurements of the value of Rx on any part of the investigated periodic (repeating) digital signal with the complete elimination of undesirable effects of sources of reference voltages on the output of the investigated device;

- the possibility of separate, independent adjustment of the measurement and emulation of the effects on the device under study, when combining these modes in real time.

The disadvantage of this meter is the appearance of amplitude measurement errors due to the presence of a chain of four series-connected sources of reference voltages in the path of the studied signal Ux to the input of the oscilloscope, which leads to an increase in spurious capacitances and inductances of the input circuits of the meter and, accordingly, reduces the accuracy and reliability of amplitude measurements.

The aim of the invention is to increase the accuracy and reliability of amplitude measurements due to the exclusion from the path of the test signal Ux to the input of the oscilloscope of series-connected reference voltage source circuits and, accordingly, reduction of stray capacitances and inductances of the meter input circuits. Along with this, when using standard measuring instruments (SSI) as part of the meter, there is no need to have isolated or differential inputs, which significantly expands the list of standard broadband oscilloscopes that can be used as part of the meter.

This goal is achieved by the fact that the oscilloscope measuring the amplitude characteristics of electrical signals containing an oscilloscope, the first output of which is connected to the first input of the zone level forming unit, the second output is to the first input of the zone pulse generator, the output of which is connected to the oscilloscope illumination input and the second input of the forming unit zone levels, and the second input of the zone pulse generator is connected to the third output of the control unit, the first output of which is connected to the third input of the zone level former , the second output - with the control input of the second switch, and the fourth output - with the control input of the first switch, the output of which is connected to the first output of the coupling capacitor, and the first and second inputs - to the first outputs of the first and second voltage sources, the second outputs of which are connected to the inputs of the voltage difference meter, and the inputs to the second output of the coupling capacitor, the inputs of the first and second continuously adjustable delay lines connected to the synchronization input of the meter, and the outputs to the first and second inputs to a switch, the output of which is connected to the synchronization input of the oscilloscope, and the first and second outputs of the zone leveling unit are connected to the inputs of the voltage equalization indicator, while the first output of the additional coupling capacitor is connected to the second input of the oscilloscope, the first output of the second communication resistor and the output of the third switch, and the second output - with the output of the first switch, the first output of the first communication resistor and the inputs of the third and fourth sources of reference voltage, the second outputs of which connected to the inputs of an additional voltage difference meter, and the first outputs with the first and second inputs of the third switch, the control input of which is connected to the fifth output of the control unit, the second terminals of the coupling resistors connected to the first input of the oscilloscope, while the first terminal of the fourth coupling capacitor is connected to the second the output of the third coupling capacitor, the first output of the fourth coupling resistor, the output of the fifth switch and the inputs of the fifth and sixth reference voltage sources, the second outputs of which connected to the inputs of the third voltage difference meter, and the first outputs with the first and second inputs of the fourth switch, the control input of which is connected to the sixth output of the control unit, the first output of the third communication resistor connected to the first output of the third communication capacitor and the output of the fourth switch, while the second the output of the fourth coupling capacitor is connected to the second input terminal of the meter and the inputs of the seventh and eighth sources of reference voltage, the second outputs of which are connected to the inputs of the four the second voltage difference meter, and the first outputs with the first and second inputs of the fifth switch, the control input of which is connected to the seventh output of the control unit, is equipped with the fifth and sixth coupling resistors, while the second terminal of the first coupling capacitor is connected to the first terminal of the sixth coupling resistor, the second terminal which is connected to the first input of the oscilloscope and the first terminal of the fifth coupling resistor, the second terminal of which is connected to the first input terminal of the meter and the second terminals of the third and fourth resistors with monitor, and the second input of the oscilloscope is connected to the second input terminal of the meter.

The technical nature of the proposed solution.

The connection of the second (common) terminal of the meter to the second (common) input of the oscilloscope eliminates the chain of four series-connected reference voltage sources from the path of the studied signal Ux to the input of the oscilloscope, which reduces the parasitic capacitances and inductances of the input circuit of the meter and, accordingly, increases the accuracy and reliability of amplitude measurements.

The separation of four series-connected sources of reference voltage into two segments, each of which includes two series-connected sources of reference voltage and which are connected, respectively, to the first (signal) terminal of the meter and the first (signal) input of the oscilloscope and interact through a communication resistor, included in the gap of the communication line between the first input terminal of the meter and the first input of the oscilloscope, provides the ability to measure the value of Rx in a two-stage version, while using uyutsya cascades of different segments and also the possibility of measuring the value Rx of a four embodiment, when using two two-stage gauges interacting modes mutual compensation of undesired effects of the reference voltage source at the input terminals of the meter. Relations are derived that ensure the fulfillment of the conditions of mutual compensation.

A positive effect of the proposed device arises from the reduction of stray capacitances and inductances of the input circuit of the meter, which provides increased accuracy of amplitude measurements, and also due to the fact that the combination of the common leads of the meter and the oscilloscope allows the use of standard measuring instruments (for example, broadband strobe oscilloscopes) that do not have isolated or differential inputs, that is, new “super-total” properties arise, in addition to providing Oleni known properties of the prototype.

The proposed set of features is not found in the known literature, therefore, meets the criteria of "novelty."

The coincidence of this set of features, as well as the properties manifested by these signs in the claimed device, which is expressed by its operating principle, with the signs and properties of technical solutions known in science and technology, has not been established.

The principle of operation of the meter is illustrated Figure 1, 2, 3 ... 5, which shows:

- figure 1 is a block diagram of a device;

- figure 2 - equivalent circuit diagrams at the input of the meter;

- figure 3 ... 5 is a timing diagram explaining the operation of the device.

The device consists of an oscilloscope 1, the first and second sources of reference voltage 2, 3, the first switch 4, the voltage difference meter 5, the first and second continuously adjustable delay lines 6 and 7, the second switch 8, the block 9 forming the level of the zones, the generator 10 pulses of the zones , voltage equality indicator 11, control unit 12, first communication capacitor 13, third and fourth voltage sources 14 and 15, third switch 16, additional voltage difference meter 17, additional capacitor 18 communication, the first and second communication resistors 19 and 20, the fifth and sixth voltage sources 21 and 22, the fourth switch 23, the third voltage difference meter 24, the third communication capacitor 25, the third communication resistor 26, the seventh and eighth voltage sources 27 and 28 , a fifth switch 29, a fourth voltage difference meter 30, a fourth coupling capacitor 31, a fourth coupling resistor 32, a fifth coupling resistor 33, and a sixth coupling resistor 34.

The device operates as follows (Figure 1). The studied periodic (repeating) digital signal Ux is input to the oscilloscope 1 (hereinafter, digital information transmission systems are considered). It is assumed that the internal resistance Ri of the sources of reference voltages 2,3; 14.15; 21.22; 27.28 much less resistance R19, R20, R26, R32, R33, R34. The resistance R20 includes the active component of the input resistance of the oscilloscope 1. The resistance values R19, R20, R26, R32, R33, R34 in the range of changes in the levels of the studied signals Ux are considered constant. The choice of the values of the coupling capacitors C13, C18, C25, C31 is made from the conditions of undistorted transmission of the form of the investigated signal Ux to the input of the oscilloscope 1. Exclusion of series-connected sources of reference voltage 2.3; 14.15; 21.22; 27,28, switches 4, 16, 23, 29 from the passage of the studied signal Ux to the input of the oscilloscope 1 provides, in combination with coupling capacitors C13, C18, C25, C31, small distortions of the studied signals in the high-frequency region due to small parasitic capacitance and inductance of the input circuit of the meter. Communication capacitors C13, C18, C25, C31 can be implemented in the form of a parallel connection of several capacitors to transmit various parts of the spectrum of the studied signal Ux, in particular, low-inductance capacitors or structural capacitors can be used to transfer high-frequency components of the spectrum.

If the input part of the meter is implemented as a remote probe, then the probe design from these elements may include only communication resistors R19, R20, R26, R32, R33, R34, small-sized capacitors (structural capacities), an input signal conversion device (for example, Stroboscopic Oscilloscope Mixer).

The equivalent input resistance of the meter (active component) is equal to:

The voltage division ratio of the investigated signal Ux at the input of the oscilloscope:

The determination of the active component in the output impedance of the source of the studied signals Ux (current values at selected time instants) is performed as follows.

The controlled signal is displayed by the controls of the oscilloscope 1 on the screen (Figure 3). The zone label using the control unit 12 is installed on the monitored portion of the signal Ux. According to the signals of the control unit 12, synchronous switching of sources of reference voltages 2,3 is performed; 14.15; 21.22; 27.28. At the same time, the voltage changes of the reference sources 2,3; 14.15; 21.22; 27.28 so that the voltage differences of the reference sources have opposite signs (for example: E1-E2 = + E1 ′, E3-E4 = -E2 ′, E5-E6 = -E3 ′, E7-E8 = + E4 ′). The shift of the investigated signal Ux along the amplitude axis that occurs in this case is perceived by the operator as a bifurcation of the signal image and the zone label. Change in the magnitude of the voltage differences of the reference sources 2,3; 14.15; 21.22; 27.28 is made in such a way as to mutually compensate for the displacement of the investigated signal Ux along the amplitude axis, which occurs from each of the pairs of reference sources 2,3; 14.15; 21.22; 27.28. The alignment control is carried out visually on the screen or by coincidence of the zone pulse marks using the voltage equalization indicator 11. Oscilloscope 1 should have direct current connections.

After the coincidence of the zone labels in the studied section of the signal Ux (value U ′ -> 0 or U ″ -> 0), at certain values of the voltage differences of the reference sources 2,3; 14.15; 21, 22, 27, 28, the value of the active component Rx in the output resistance of the source of the studied signals Ux is calculated.

Rx can be measured using two, three, or four stages in various combinations.

Below are the derived ratios for a number of different combinations of cascades used.

The derived relation for calculating Rx at E1 ′, E3 ′ ≠ 0; E2 ′, E4 ′ = 0:

The derived relation for calculating Rx at E2 ′, E4 ′ ≠ 0; E′1, E3 ′ = 0:

The derived relation for calculating Rx, for E2 ′, E3 ′ ≠ 0; E1 ′, E4 ′ = 0:

The derived relation for calculating Rx, for E1 ′, E4 ′ ≠ 0; E2 ′, E3 ′ = 0:

The value of Rx is part of the active output impedance of the source of the studied signals - Rist., Measured at direct current. In the steady sections of the signal under study, Rx -> Rist.

When determining Rx, the values E1 ′, E2 ′, E3 ′, E4 ′ are measured by voltage difference meters 5, 17, 24, 30, and the values R19, R20, R26, R32, R33, R34 are known.

Similarly, the value of Rx is determined in the output impedance of the source of the studied signals Ux at any time, in accordance with the portion selected in the image of the signal Ux, see (Figure 3).

The measured values of the value of Rx (Rx13, Rx24, Rx14, Rx23), with different combinations of the used cascades, should be identical and may differ in the case of the dependence of the value of Rx on the effects of differences in voltage drop across the input terminals of the meter (Ux ′).

The procedure for measuring the value of Rx and the requirements for the ratio of the values of E1 ′, E2 ′, E3 ′, E4 ′ will be discussed in detail below.

To derive the main dependencies, we consider simplified equivalent circuit circuits at the input of the meter (Figure 2).

Accordingly, you can write the ratio:

where Uo1 ′, Uo2 ′, Uo3 ′, Uo4 ′ are the differences of the voltage drops at the coupling resistor R20 (at the input of the oscilloscope 1);

Ux1 ′, Ux2 ′, Ux3 ′, Ux4 ′ - differences of voltage drops at the output resistance of the source of the studied signals (at the input terminals of the meter);

U _R33 1 ′, U _R33 2 ′, U _R33 3 ′, U _R33 4 ′ - differences of voltage drops on the coupling resistor R33.

The image of the signal under study on the screen of the oscilloscope 1 is shifted along the amplitude axis in proportion to the magnitude of the differences in voltage drops Uo1 ′, Uo2 ′, Uo3 ′, Uo4 ′.

Since when measuring the value of Rx, mutual compensation of the displacements of the studied signal Ux along the axis of amplitudes originating from each of the pairs of voltage reference sources 2,3 is performed; 14.15; 21.22; 27.28, then from relations (7) it follows:

Uo1 ′ + Uo2 ′ + Uo3 ′ + Uo4 ′ = 0;

and correspondingly:

We determine the quantities Ux1 ′, Ux2 ′, Ux3 ′, Ux4 ′ through the known values of the coupling resistors R19, R20, R26, R32, R33, R34, the measured values of the voltage differences of the reference sources E1 ′, E2 ′, E3 ′, E4 ′ and the value Rx (see equivalent circuit circuits at the input of the meter (Figure 2)):

- where the coefficient N is respectively equal to:

Since switching voltage reference sources 2.3; 14.15; 21.22; 27.28 is performed synchronously, the resulting effect of the differences in voltage drops on Rx is respectively equal to:

From a consideration of the circuit diagrams at the input of the meter (Figure 2), we determine the differences of the voltage drops Uo1 ′, Uo2 ′, Uo3 ′, Uo4 ′ at the input of the oscilloscope through the known values of the coupling resistors R19, R20, R26, R32, R33, R34, the measured values of the differences voltage reference sources E1 ′, E2 ′, E3 ′, E4 ′ and the value of Rx:

The resulting effect of the differences in voltage drops Uo1 ′, Uo2 ′, Uo3 ′, Uo4 ′ at the input of the oscilloscope 1 and, accordingly, the displacement of the signal under study Ux along the amplitude axis on the oscilloscope screen is:

Consider the possible options for the four-stage meter circuit when measuring Rx when two stages are used:

- the option when the first and third stages are used, respectively E2 ′ and E4 ′ are equal to zero:

Substituting relations (15), (17) into equation (20) and solving it with respect to Rx, we obtain relation (3);

- the option when the second and fourth cascades are used, respectively E1 ′ and E3 ′ are equal to zero:

Substituting relations (16), (18) into equation (21) and solving it with respect to Rx, we obtain relation (4);

- the option when the second and third stages are used, respectively E1 ′ and E4 ′ are equal to zero:

Substituting relations (16), (17) into equation (22) and solving it with respect to Rx, we obtain relation (5);

- option when the first and fourth cascades are used, respectively E2 ′ and E3 ′ are equal to zero:

Substituting relations (15), (18) into equation (23) and solving it with respect to Rx, we obtain relation (6).

When the meter is operating in a two-stage version, when measuring Rx, the first, third are used alternately; second, fourth; second third; first, fourth cascades.

The calculation of the values of Rx13, Rx24, Rx23, Rx14 is carried out in accordance with the relations (3) ... (6). When determining the values of Rx13, Rx24, Rx23, Rx14, the values of Uo13 ′, Uo24 ′, Uo23 ′, Uo14 ′ are set to 0 visually on the oscilloscope screen 1 or by coincidence of the zone pulse marks using the voltage equalization indicator 11.

In Clauses 1 ... 4, 5 ... 8 of Table 1, as an example, the calculation results are given for measurements of Rx at R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm.

From a consideration of the measurement results, it follows that the device under study is under the resulting influence of the voltage drop differences Ux ′ (Ux13 ′, Ux24 ′, Ux23 ′, Ux14 ′), which can interfere with the operation of the studied device and reduce the reliability and accuracy of measurements.

Table 1 U, E, R \ nn Formula (No. xxx) one 2 3 four Note Uo ′, V 19 (87) 0 0 0 0 Uo2 ′, V 16 (84) 0 0 0.509804 0.5105566 Uo1 ′, V 15 (83) -0.254902 -0.2552783 0 0 Uo3 ′, V 17 (85) 0.254902 0.2552783 0 0 Uo4 ′, V 18 (86) 0 0 -0.509804 -0.5105566 E2 ′, V 0 0 one one E1 ′, V -one -one 0 0 E3 ′, V 13 12.09091 0 0 E4 ′, V 0 0 -13 -12.09091 E3 ′ / E1 ′ -13 -12.09091 - - E4 ′ / E2 ′ - - -13 -12.09091 Ux2 ′, V 10 (78) 0 0 3.921569 E-02 4.222649 E-02 Ux1 ′, V 9 (77) -1.960784 E-02 -2.111324 E-02 0 0 Ux3 ′, V 11 (79) 1.019608 1.021113 0 0 Ux4 ′, V 12 (80) 0 0 -2.039216 -2.042227 Ux13 ′, V one one 0 0 Ux24 ′, V 0 0 -2 -2 Ux ′, V 14 (82) one one -2 -2 Rx13, kOm 3 (73) one hundred 110 - - Rx24, kOm 4 (74) - - one hundred 110

Let us consider two variants of the meter operation in the measurement mode of the Rx value when four stages are used.

When the meter operates in a four-stage version, when measuring Rx, we have the synchronous operation of two two-stage meters operating in antiphase (from the point of view of influencing the device under study), in order to eliminate the undesirable resulting effect of voltage drop differences Ux1 ′, Ux2 ′, Ux3 ′, Ux4 ′, to the device under investigation. Since the common conclusions of the meter and the oscilloscope are connected, the circuit of the test signal Ux to the input of the oscilloscope (Fig.2e) has minimal spurious parameters (Lpar., Spar.), And it is also possible to use standard high-speed oscilloscopes that do not have isolated or differential inputs.

Table 1 - continued U, E, R \ nn Formula (No. xxx) 5 6 7 8 Note Uo ′, V 19 (87) 0 0 0 0 Uo2 ′, V 16 (84) 0.254902 0.2552783 0 0 Uo1 ′, V 15 (83) 0 0 0.254902 0.2552783 Uo3 ′, V 17 (85) -0.254902 -0.2552783 0 0 Uo4 ′, V 18 (86) 0 0 -0.254902 -0.2552783 E2 ′, V 0.5 0.5 0 0 E1 ′, V 0 0 one one E3 ′, V -13 -12.09091 0 0 E4 ′, V 0 0 -6.5 -6.045455 E3 ′ / E2 ′ -26 -24.18182 - - E4 ′ / E1 ′ - - -6.5 -6.045455 Ux2 ′, V 10 (78) 1.960784 E-02 2.111324 E-02 0 0 Ux1 ′, V 9 (77) 0 0 1.960784 E-02 2.111324 E-02 Ux3 ′, V 11 (79) -1.019608 -1.021113 0 0 Ux4 ′, V 12 (80) 0 0 -1.019608 -1.021113 Ux14 ′, V 0 0 -one -one Ux23 ′, V -one -one 0 0 Ux ′, V 14 (82) -one -one -one -one Rx23 kOm 5 (75) one hundred 110 - - Rx14 kOm 6 (76) - - one hundred 110

Consider the first version of the meter in the four-stage version, respectively, you can write the ratio:

Substituting relations (9), (10), (11), (12) into equation (24) and performing the transformations, we obtain relation (25):

и

определяются в процессе измерения величин Rx13 и Rx24 [см. соотношения (3) и (4)], поэтому, после проведения вычислений в соответствии с соотношением (25), возможно определить значение соотношения

.The ratio

and

are determined by measuring Rx13 and Rx24 [see relations (3) and (4)], therefore, after performing calculations in accordance with relation (25), it is possible to determine the value of the relation

.

,

,

, установить абсолютные значения остальных величин.Setting the absolute value of one of the values E1 ′, E2 ′ E3 ′, E4 ′ during measurements, it is possible, subject to the established ratios

,

,

, establish the absolute values of the remaining quantities.

If necessary, several iterations are performed to refine the value of Rx and, accordingly, to refine the ratios of the quantities E1 ′, E2 ′, E3 ′, E4 ′.

A gradual increase in the absolute values of the values E1 ′, E2 ′, E3 ′, E4 ′ minimizes the possible undesirable resulting effects of the voltage drop differences Ux1 ′, Ux2 ′, Ux3 ′, Ux4 ′ on the device under study at the stage of updating the value of Rx.

,

, при проведении измерений величины Rx в четырехкаскадном варианте.Define the relationship between the relations

,

, when measuring Rx values in a four-stage version.

и

, вне зависимости от величины Rx:In the synchronous operation of two two-stage meters, the values of Rx13 and Rx24 are determined in the controlled area of the signal under study in accordance with relations (3) and (4). The measurement results of each of the two-stage meters should be equal - Rx13 = Rx24. Accordingly, after transformations of relations (3) and (4), we obtain an expression defining the relationship of relations

and

, regardless of the value of Rx:

и

должна соответствовать выражению (26).When setting the absolute values of the quantities E1 ′, E2 ′, E3 ′, E4 ′, when measuring Rx, the relationship of the relations

and

must correspond to expression (26).

In clauses 9, 10 of Table 1, as an example, the calculation results are given when measuring Rx values at R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm.

Consider the second version of the meter in a four-stage version, respectively, you can write the ratio:

Substituting relations (9), (10), (11), (12) into equation (27) and performing the transformations, we obtain relation (28):

и

определяются в процессе измерения величин Rx14 и Rx23 [см. соотношения (5) и (6)], поэтому, после проведения вычислений в соответствии с соотношением (28), возможно определить значение

.The ratio

and

determined during the measurement of Rx14 and Rx23 [see relations (5) and (6)], therefore, after performing calculations in accordance with relation (28), it is possible to determine the value

.

,

,

, установить абсолютные значения остальных величин.Setting the absolute value of one of the quantities E1 ′, E2 ′, E3 ′, E4 ′ during the measurement process, possibly, subject to the established ratios

,

,

, establish the absolute values of the remaining quantities.

If necessary, several iterations are performed to refine the value of Rx and, accordingly, to refine the ratios of the quantities E1 ′, E2 ′, E3 ′, E4 ′.

A gradual increase in the absolute values of the values E1 ′, E2 ′, E3 ′, E4 ′ minimizes the possible undesirable resulting effects of the voltage drop differences Ux1 ′, Ux2 ′, Ux3 ′, Ux4 ′ on the device under study at the stage of updating the value of Rx.

и

при проведении измерении величины Rx в четырехкаскадном варианте.Define the relationship between the relations

and

when measuring Rx in a four-stage version.

и

, вне зависимости от величины Rx:During the synchronous operation of two two-stage meters, the values of Rx14h Rx23 are determined in the controlled area of the signal under study in accordance with relations (5) and (6). The measurement results of each of the two-stage meters should be equal - Rx14 = Rx23. Accordingly, after transformations of relations (5) and (6), we obtain an expression defining the relationship of relations

and

, regardless of the value of Rx:

и

должна соответствовать выражению (29).When setting the absolute values of the quantities E1 ′, E2 ′, E3 ′, E4 ′, when measuring Rx, the relationship of the relations

and

must correspond to expression (29).

In clauses 11, 12 of Table 1, as an example, the calculation results are given when measuring Rx values at R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm.

Amplitude measurements of the studied signals are carried out as follows. The investigated signal using the controls of the oscilloscope 1 is displayed on the screen (Figure 4). The zone labels are set on the sections of the studied signal Ux, between which amplitude measurements are carried out. According to the signals of the control unit 12, synchronous switching of the voltage reference sources 2.3 is performed; 14.15; 21.22; 27.28, as well as continuously adjustable delay lines 6, 7. At the same time, the voltage of the reference sources 2.3 is changed; 14.15; 21.22; 27.28 and the values of the delay of the delay lines 6.7 to align the labels of the zones on the signal under study (Figure 4). The combination of zone labels can be performed at high sensitivity of the oscilloscope 1 and at “fast” sweeps.

Let us consider a number of variants of amplitude measurements when the influence of the voltage differences of the reference sources (E1 ... E4 ′) on the device under study is undesirable, that is, the ratio of the values E1 ′ ... E4 ′ must be such that the compensation condition Ux ′ = 0 is constantly observed, regardless of Rx values.

The first variant of amplitude measurements is that E2 ′ = 0, E4 ′ = 0; respectively, Uo2 ′, Uo4 ′ and Ux2 ′, Uo4 ′ are also equal to zero.

From consideration of equivalent circuits at the input of the meter (Figure 2) it follows:

Table 1 - continued U, E, R \ nn Formula (No. xxx) 9 10 eleven 12 Note Uo ′, V 19 (87) 0 0 0 0 Uo2 ′, V 16 (84) 0.254902 0.2552783 0.254902 0.2552783 Uo1 ′, V 15 (83) -0.254902 -0.2552783 -0.254902 -0.2552783 Uo3 ′, V 17 (85) 0.254902 0.2552783 -0.254902 -0.2552783 Uo4 ′, V 18 (86) -0.254902 -0.2552783 0.254902 0.2552783 E2 ′, V 0.5 0.5 0.5 0.5 E1 ′, V -one -one -one -one E3 ′, V 13 12.09091 -13 -12.09091 E4 ′, V -6.5 -6.045455 6.5 6.045455 E3 ′ / E1 ′ -13 -12.09091 - - E4 ′ / E2 ′ -13 -12.09091 - - E3 ′ / E2 ′ - - -26 -24.18182 E4 ′ / E1 ′ - - -6.5 -6.045455 E1 ′ / E2 ′ 25.28 (88, 90) -2 -2 -2 -2 Ux2 ′, V 10 (78) 1.960784 E-02 2.111324 E-02 1.960784 E-02 2.111324 E-02 Ux1 ′, V 9 (77) -1.960784 E-02 -2.111324-E-02 -1.960784-E-02 -2.111324 E-02 Ux3 ′, V 11 (79) 1.019608 1.021113 -1.019608 -1.021113 Ux4 ′, V 12 (80) -1.019608 -1.021113 1.019608 1.021113 Ux13 ′, V one one - - Ux24 ′, V -one -one - - Ux14 ′, V - - one one Ux23 ′, V - - -one -one Ux ′, V 14 (82) 0 0 0 0 Rx13, kOm 3 (73) one hundred 110 - - Rx24, kOm 4 (74) one hundred 110 - - Rx23 kOm 5 (75) - - one hundred 110 Rx14 kOm 6 (76) - - one hundred 110

After substituting expressions (9), (11) into relations (30), (31); (15), (17) and transformations we get:

Thus, the change in the voltage differences E1 ′, E3 ′, when conducting amplitude measurements, is performed before combining the zone labels in the controlled areas of the studied signal Ux (Figure 4) in compliance with relation (32). After combining the zone labels, the amplitude of the studied signal Ux is determined in accordance with relation (33), taking into account the division ratio of the voltage of the studied signal Ux at the input of the oscilloscope Ux = Kdel.Uo ′ (see relation 2), and the influence of the reference voltage sources on investigated device (Ux ′ = 0).

In relations (32), (33), the values of R19, R20, R26, R33, R34 are known, and the values of E1 ′, E3 ′ are measured by voltage difference meters 5, 24.

In paragraphs 13, 14 of Table 1, as an example, the results of calculations are given for measurements of the amplitude of the studied signal Ux = 3B (Ux = Kdel.Uo ′). The calculations were made taking into account relations (32), (33) for two values of Rx - 15 kOhm and 100 kOhm, with R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm.

If during amplitude measurements it is required to establish a certain value of Uo ′, with the exception of the influence of voltage differences of the reference sources E1 ′, E3 ′ on the device under study (Ux ′ = 0), the values of E1 ′, E3 ′ are set in accordance with the transformed relations (32 ), (33):

This variant of amplitude measurements can be used to set the boundary values, when studying signals with a changing amplitude, and also to calibrate the amplitude scale of the oscilloscope.

Given the quantity Uo ′, we determine, in accordance with relations (34), (35), the quantities E1 ′, E3 ′.

After setting the calculated values of the values E1 ′, E3 ′, the shift of the signal under investigation on the screen of the oscilloscope 1 along the amplitude axis corresponds to the specified value Uo ′, regardless of the value of Rx and at Ux ′ = 0. Using the obtained shift of the investigated signal Ux along the axis of amplitudes, in combination with the shift of the studied signal Ux along the time axis, when switching the delay lines 6 and 7, it is possible to carry out amplitude measurements (Figure 4).

In clauses 15, 16 of Table 1, as an example, the results of calculations are given for measurements at Uo ′ = 3.5B. The calculations were made taking into account relations (40), (41) for two values of Rx - 15 kOhm and 100 kOhm, with R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm.

The second variant of amplitude measurements is that E1 ′ = 0, E3 ′ = 0; respectively, Uo1 ′, Uo3 ′ and Ux1 ′, Uo3 ′ are also equal to zero.

From consideration of equivalent circuits at the input of the meter (Figure 2) it follows:

Table 1 - continued U, E, R \ nn Formula (No. xxx) 13 fourteen fifteen 16 Note Uo ′, V 19 (87) 0.75 0.75 3.5 3.5 Ux, V 3 3 fourteen fourteen Uo2 ′, V 16 (84) 0 0 0 0 Uo1 ′, V 15 (83) 0.7527011 0.7647059 3.512605 3.568627 Uo3 ′, V 17 (85) -2.70108 E-03 -1.470588 E-02 -1.260504 E-02 -6.862745 E-02 Uo4 ′, V 18 (86) 0 0 0 0 E2 ′, V 0 0 0 0 E1 ′, V 3 3 fourteen fourteen E3 ′, V -0.75 -0.75 -3.5 -3.5 E4 ′, V 0 0 0 0 Ux2 ′, V 10 (78) 0 0 0 0 Ux1 ′, V 9 (77) 1.080432 E-02 5.882353 E-02 5.042017 E-02 0.2745098 Ux3 ′, V 11 (79) -1.080432 E-02 -5.882353 E-02 -5.042017 E-02 -0.2745098 Ux4 ′, V 12 (80) 0 0 0 0 Ux13 ′, V 0 0 0 0 Ux24 ′, V 0 0 0 0 Ux ′, V 14 (82) 0 0 0 0 Rx, kOm fifteen one hundred fifteen one hundred

After substituting expressions (10), (12) into relations (36), (37); (16), (18) and transformations we get:

Thus, the change in the voltage differences E2 ′, E4 ′, when conducting amplitude measurements, is performed before combining the zone labels in the controlled areas of the studied signal Ux (Figure 4) in compliance with the relation (38). After combining the zone labels, the amplitude of the studied signal Ux is determined in accordance with relation (39), taking into account the division ratio of the voltage of the studied signal Ux at the input of the oscilloscope Ux = Kdel.Uo ′ (see relation 2), and the influence of the reference voltage sources on investigated device (Ux ′ = 0).

In relations (38), (39), the values of R19, R20, R26, R32, R33, R34 are known, and the values of E2 ′, E4 ′ are measured by voltage difference meters 17, 30.

In clauses 17, 18 of Table 1, as an example, the calculation results are given for measurements of the amplitude of the studied signal Ux = 6B (Ux = Kdel.Uo ′). The calculations were made taking into account relations (38), (39) for two values of Rx - 15 kOhm and 100 kOhm, with R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm.

If during amplitude measurements it is required to establish a certain value of Uo ′, with the exception of the influence of voltage differences of the reference sources E2 ′, E4 ′ on the device under study (Ux ′ = 0), the values of E2 ′, E4 ′ are set in accordance with the transformed relations (38 ), (39):

This variant of amplitude measurements can be used to set the boundary values, when studying signals with a changing amplitude, and also to calibrate the amplitude scale of the oscilloscope.

Given the quantity Uo ′, we determine, in accordance with relations (40), (41), the quantities E2 ′, E4 ′.

After setting the calculated values of the values of E2 ′, E4 ′, the displacement of the signal under investigation on the screen of the oscilloscope 1 along the amplitude axis corresponds to the specified value Uo ′, regardless of the value of Rx and at Ux ′ = 0. Using the obtained shift of the investigated signal Ux along the axis of amplitudes, in combination with the shift of the studied signal Ux along the time axis, when switching the delay lines 6 and 7, it is possible to carry out amplitude measurements (Figure 4).

In paragraphs 19, 20 of Table 1, as an example, the calculation results are given for measurements at Uo ′ = 3.5B. The calculations were made taking into account relations (40), (41) for two values of Rx - 15 kOhm and 100 kOhm, with R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm.

The third variant of amplitude measurements is that E1 ′ = 0, E4 ′ = 0; respectively, Uo1 ′, Uo4 ′ and Ux1 ′, Uo4 ′ are also equal to zero.

From consideration of equivalent circuits at the input of the meter (Figure 2) it follows:

Table 1 - continued U, E, R \ nn Formula (No. xxx) 17 eighteen 19 twenty Note Uo ′, V 19 (87) 1.5 1.5 3.5 3.5 Ux, V 6 6 fourteen fourteen Uo2 ′, V 16 (84) 1.505402 1.529412 3.512605 3.568627 Uo1 ′, V 15 (83) 0 0 0 0 Uo3 ′, V 17 (85) 0 0 0 0 Uo4 ′, V 18 (86) -5.402161 E-03 -2.941176 E-02 -1.260504 E-02 -6.862745 E-02 E2 ′, V 3 3 7 7 E1 ′, V 0 0 0 0 E3 ′, V 0 0 0 0 E4 ′, V -0.75 -0.75 -1.75 -1.75 Ux2 ′, V 10 (78) 2.160864 E-02 0.1176471 5.042017 E-02 0.2745098 Ux1 ′, V 9 (77) 0 0 0 0 Ux3 ′, V 11 (79) 0 0 0 0 Ux4 ′, V 12 (80) -2.160864 E-02 -0.1176471 -5.042017 E-02 -0.2745098 Ux13 ′, V 0 0 0 0 Ux24 ′, V 0 0 0 0 Ux ′, V 14 (82) 0 0 0 0 Rx, kOm fifteen one hundred fifteen one hundred

After substituting expressions (10), (11) into relations (42), (43); (16), (17) and transformations we get:

Thus, the change of voltage differences E2 ′, E4 ′, when conducting amplitude measurements, is performed before combining the zone labels in the controlled areas of the studied signal Ux (Figure 4) in compliance with the relation (44). After combining the zone labels, the amplitude of the studied signal Ux is determined in accordance with relation (45), taking into account the division ratio of the voltage of the studied signal Ux at the input of the oscilloscope Ux = Kdel.Uo ′ (see relation 2), while the influence of the reference voltage sources on investigated device (Ux ′ = 0).

In relations (44), (45), the values of R19, R20, R26, R33, R34 are known, and the values of E2 ′, E4 ′ are measured by voltage difference meters 17, 24.

In paragraphs 21, 22 of Table 1, as an example, the calculation results are given for measuring the amplitude of the studied signal Ux = 6B (Ux = Kdel.Uo ′). The calculations were made taking into account relations (44), (45) for two values of Rx - 15 kOhm and 100 kOhm, with R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm.

If during amplitude measurements it is required to establish a certain value of Uo ′, with the exception of the influence of voltage differences of the reference sources E2 ′, E3 ′ on the device under study (Ux ′ = 0), the values of E2 ′, E3 ′ are set in accordance with the transformed relations (44 ), (45):

This variant of amplitude measurements can be used to set the boundary values, when studying signals with a changing amplitude, and also to calibrate the amplitude scale of the oscilloscope.

Given the quantity Uo ′, we determine, in accordance with relations (46), (47), the quantities E2 ′, E3 ′.

After setting the calculated values of the values of E2 ′, E3 ′, the shift of the signal under investigation on the screen of the oscilloscope 1 along the amplitude axis corresponds to the specified value Uo ′, regardless of the value of Rx and at Ux ′ = 0. Using the obtained shift of the investigated signal Ux along the axis of amplitudes, in combination with the shift of the studied signal Ux along the time axis, when switching the delay lines 6 and 7, it is possible to carry out amplitude measurements (Figure 4).

In paragraphs 23, 24 of Table 1, as an example, the calculation results are given for measurements at Uo ′ = 3.5B. The calculations were made taking into account relations (46), (47) for two values of Rx - 15 kOhm and 100 kOhm, with R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm.

The fourth variant of amplitude measurements is that E2 ′ = 0, E3 ′ = 0; respectively, Uo2 ′, Uo3 ′ and Ux2 ′, Uo3 ′ are also equal to zero.

From consideration of equivalent circuits at the input of the meter (Figure 2) it follows:

Table 1 - continued U, E, R \ nn Formula (No. xxx) 21 22 23 24 Note Uo ′, V 19 (87) 1.5 1.5 3.5 3.5 Ux, V 6 6 fourteen fourteen Uo2 ′, V 16 (84) 1.505402 1.529412 3.512605 3.568627 Uo1 ′, V 15 (83) 0 0 0 0 Uo3 ′, V 17 (85) -5.402161 E-02 -2.941176 E-02 -1.260504 E-02 -6.862745 E-02 Uo4 ′, V 18 (86) 0 0 0 0 E2 ′, V 3 3 7 7 E1 ′, V 0 0 0 0 E3 ′, V -1.5 -1.5 -3.5 -3.5 E4 ′, V 0 0 0 0 Ux2 ′, V 10 (78) 2.160864 E-02 0.1176471 5.042017 E-02 0.2745098 Ux1 ′, V 9 (77) 0 0 0 0 Ux3 ′, V 11 (79) -2.160864 E-02 -0.1176471 -5.042017 E-02 -0.2745098 Ux4 ′, V 12 (80) 0 0 0 0 Ux14 ′, V 0 0 0 0 Ux23 ′, V 0 0 0 0 Ux ′, V 14 (82) 0 0 0 0 Rx kOm fifteen one hundred fifteen one hundred

After substituting expressions (9), (12) into relations (48), (49); (15), (18) and transformations we get:

Thus, the change in the voltage differences E1 ′, E4 ′, when conducting amplitude measurements, is performed before combining the zone labels in the controlled areas of the studied signal Ux (Figure 4) in compliance with the relation (50). After combining the zone labels, the amplitude of the studied signal Ux is determined in accordance with relation (51), taking into account the division ratio of the voltage of the studied signal at the input of the oscilloscope Ux = Kdel.Uo ′ (see relation 2), while the influence of the reference voltage sources on the studied device (Ux ′ = 0).

In relations (50), (51), the values of R19, R20, R26, R32, R33, R34 are known, and the values of E1 ′, E4 ′ are measured by voltage difference meters 5, 30.

In paragraphs 25, 26 of Table 1, as an example, the calculation results are given for measurements of the amplitude of the studied signal Ux = 3B (Ux = Kdel.Uo ′). The calculations were made taking into account relations (50), (51) for two values of Rx - 15 kOhm and 100 kOhm, with R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm.

If during amplitude measurements it is required to establish a certain value of Uo ′, with the exception of the influence of voltage differences of the reference sources E1 ′, E4 ′ on the device under study (Ux ′ = 0), the values of E1 ′, E4 ′ are set in accordance with the transformed relations (50 ), (51):

This variant of amplitude measurements can be used to set the boundary values, when studying signals with a changing amplitude, and also to calibrate the amplitude scale of the oscilloscope.

Given the quantity Uo ′, we determine, in accordance with relations (52), (53), the quantities E1 ′, E4 ′.

After setting the calculated values of the values of E1 ′, E4 ′, the displacement of the signal under study on the screen of the oscilloscope 1 along the amplitude axis corresponds to the specified value Uo ′, regardless of the value of Rx and at Ux ′ = 0. Using the obtained shift of the investigated signal Ux along the axis of amplitudes, in combination with the shift of the studied signal Ux along the time axis, when switching the delay lines 6 and 7, it is possible to carry out amplitude measurements (Figure 4).

In paragraph 27.28 of Table 1, as an example, the calculation results are given for measurements at Uo ′ = 3.5V. The calculations were made taking into account relations (52), (53) for two values of Rx - 15 kOhm and 100 kOhm, at R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm.

Let us consider a number of variants of amplitude measurements when the resulting effect of the differences in voltage drops Ux ′ is used as a means of emulating the effects on the device under study, while two stages in the input circuit of the meter are used for amplitude measurements and operate in modes that exclude their effect on the device under study, and two other cascades are used to emulate the effects on the device under study and operate in modes that exclude their influence on the input of the oscilloscope, while flax measured value Rx in the studied areas Ux is a constant signal.

The first variant of amplitude measurements - we assume that the first and third stages are used for amplitude measurements and operate in accordance with the procedures described above (see relations (30) ... (35)), while the second and fourth stages are used to emulate the effects on the test device.

From consideration of equivalent circuits at the input of the meter (Figure 2) it follows:

After substituting expressions (16), (18) into relations (54), (55); (10), (12) and transformations we get:

Given the value Ux ′, we determine, in accordance with relations (56), (57), the values of E2 ′ and E4 ′, and the influence of the voltage differences of the reference sources E2 ′, E4 ′ on the input of the oscilloscope (Uo ′ = 0) is excluded.

In relations (56), (57), the values of R19, R26, R32, R33, R34 are known, the value of Ux ′ is specified, the value of Rx in the controlled section of the signal under investigation Ux is determined previously, in accordance with the previously derived relations (24) ... (26 ) or (27) ... (29), and the quantities E2 ′, E4 ′ are measured by voltage difference meters 17, 30.

In paragraphs 29, 30 of Table 1, as an example, the results of calculations are given for measuring the amplitudes of the studied signals Ux = 12B and Ux = 6B (Ux = Kdel.Uo ′). The calculations were made taking into account relations (30) ... (35), (54) ... (57) at Ux ′ = 2B, Rx = 100 kOhm, R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm. The division coefficient of the studied signal Ux at the input of the oscilloscope Kdel. = 4 (see relation (2)).

Table 1 - continued U, E, R \ nn Formula (No. xxx) 25 26 27 28 Note Uo ′, V 19 (87) 0.75 0.75 3.5 3.5 Ux, V 3 3 fourteen fourteen Uo2 ′, V 16 (84) 0 0 0 0 Uo1 ′, V 15 (83) 0.7527011 0.7647059 3.512605 3.568627 Uo3 ′, V 17 (85) 0 0 0 0 Uo4 ′, V 18 (86) -2.70108 E-03 -1.470588 E-02 -1.260504 E-02 -6.862745 E-02 E2 ′, V 0 0 0 0 E1 ′, V 3 3 fourteen fourteen E3 ′, V 0 0 0 0 E4 ′, V -0.375 -0.375 -1.75 -1.75 Ux2 ′, V 10 (78) 0 0 0 0 Ux1 ′, V 9 (77) 1.080432 E-02 5.882353 E-02 5.042017 E-02 0.2745098 Ux3 ′, V 11 (79) 0 0 0 0 Ux4 ′, V 12 (80) -1.080432 E-02 -5.882353 E-02 -5.042017 E-02 -0.2745098 Ux14 ′, V 0 0 0 0 Ux23 ′, V 0 0 0 0 Ux ′, V 14 (82) 0 0 0 0 Rx, kOm fifteen one hundred fifteen one hundred

The second variant of amplitude measurements - we assume that the second and fourth cascades are used for amplitude measurements and operate in accordance with the procedures described above (see relations (36) ... (41)), while the first and third cascades are used to emulate the effects on the test device.

From consideration of equivalent circuits at the input of the meter (Figure 2) it follows:

After substituting expressions (15), (17) into relations (58), (59); (9), (11) and transformations we get:

Given a value of Ux ′, we determine, in accordance with relations (60), (61), the values of E1 ′ and E3 ′, and the influence of the voltage differences of the reference sources E1 ′, E3 ′ on the input of the oscilloscope (Uo ′ = 0) is excluded.

In relations (60), (61), the values of R26, R32, R33, R34 are known, the value Ux ′ is specified, the value Rx, in the controlled area of the signal under investigation Ux, is determined previously, in accordance with the previously derived relations (24) ... (26) or (27) ... (29), and the values E1 ′, E3 ′ are measured by voltage difference meters 5, 24.

In paragraphs 31, 32 of Table 1, as an example, the calculation results are given for measurements of the amplitudes of the studied signals Ux = 12V and Ux = 6B (Ux = Kdel.Uo ′). The calculations were made taking into account relations (36) ... (41), (58) ... (61) at Ux ′ = 2B, Rx = 100 kOhm, R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm. The division coefficient of the studied signal Ux at the input of the oscilloscope Kdel. = 4 (see relation (2)).

The third variant of amplitude measurements - we assume that the second and third stages are used for amplitude measurements and operate in accordance with the procedures described above (see relations (42) ... (47)), while the first and fourth stages are used to emulate the effects on the test device.

From consideration of equivalent circuits at the input of the meter (Figure 2) it follows:

After substituting expressions (15), (18) into relations (62), (63); (9), (12) and transformations we get:

Given the value Ux ′, we determine, in accordance with relations (60), (61), the values of E1 ′ and E3 ′, and the influence of the voltage differences of the reference sources E1 ′, E3 ′ on the input of the oscilloscope (Uo ′ = 0) is excluded.

In relations (60), (61), the values of R26, R32, R33, R34 are known, the value Ux ′ is specified, the value Rx, in the controlled area of the signal under investigation Ux, is determined previously, in accordance with the previously derived relations (24) ... (26) or (27) ... (29), and the values E1 ′, E4 ′ are measured by voltage difference meters 5, 30.

Table 1 - continued U, E, R \ nn Formula (No.xxx) 29th thirty 31 32 Note Uo ′, V 19 (87) 3 1.5 3 1.5 Ux, V 12 6 12 6 Uo2 ′, V 16 (84) -0.509804 -0.509804 3.058824 1.529412 Uo1 ′, V 15 (83) 3.058824 1.529412 -0.509804 -0.509804 Uo3 ′, V 17 (85) -5.882353 E-02 -2.941176 E-02 0.509804 0.509804 Uo4 ′, V 18 (86) 0.509804 0.509804 -5.882353 E-02 -2.941176 E-02 E2 ′, V -one -one 6 3 E1 ′, V 12 6 -2 -2 E3 ′, V -3 -1.5 26 26 E4 ′, V 13 13 -1.5 -0.75 Ux2 ′, V 10 (78) -3.921569 E-02 -3.921569 E-02 0.2352941 0.1176471 Ux1 ′, V 9 (77) 0.2352941 0.1176471 -3.921569 E-02 -3.921569 E-02 Ux3 ′, V 11 (79) -0.2352941 -0.1176471 2.039216 2.039216 Ux4 ′, V 12 (80) 2.039216 2.039216 -0.2352941 -0.1176471 Ux13 ′, V 0 0 2 2 Ux24 ′, V 2 2 0 0 Ux ′, V 14 (82) 2 2 2 2 Rx, kOm one hundred one hundred one hundred one hundred

In paragraphs 33, 34 of Table 1, as an example, the calculation results are given for measurements of the amplitudes of the studied signals Ux = 12B and Ux = 6B (Ux = Kdel.Uo ′). The calculations were made taking into account relations (42) ... (47), (62) ... (65) at Ux ′ = 2B, Rx = 100 kOhm, R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm. The division coefficient of the studied signal Ux at the input of the oscilloscope Kdel. = 4 (see relation (2)).

The fourth variant of amplitude measurements - we assume that the first and fourth cascades are used for amplitude measurements and operate in accordance with the above procedures (see relations (48) ... (53)), while the second and third cascades are used to emulate the effects on the studied device.

From consideration of equivalent circuits at the input of the meter (Figure 2) it follows:

After substituting into expressions (66), (67) expressions (16), (17); (10), (11) and transformations we get:

Given the value Ux ′, we determine, in accordance with relations (68), (69), the values of E2 ′ and E3 ′, and the influence of the voltage differences of the reference sources E2 ′, E3 ′ on the input of the oscilloscope (Uo ′ = 0) is excluded.

In relations (68), (69), the values of R19, R26, R32, R33, R34 are known, the value of Ux ′ is specified, the value of Rx, in the controlled area of the signal Ux under investigation, is determined previously, in accordance with the previously derived relations (24) ... ( 26) or (27) ... (29), and the quantities E2 ′, E3 ′ are measured by voltage difference meters 17, 24.

In paragraphs 35, 36 of Table 1, as an example, the calculation results are given for measurements of the amplitudes of the studied signals Ux = 12V and Ux = 6B (Ux = Kdel.Uo ′). The calculations were made taking into account relations (48) ... (53), (66) ... (69) at Ux ′ = 2B, Rx = 100 kOhm, R19 = R20 = R26 = R32 = R33 = R34 = 1000 kOhm. The division coefficient of the investigated signal Ux at the input of the oscilloscope Kdel. = 4 (see relation (2)).

When conducting amplitude measurements, when the resulting effect of the voltage differences Ux ′ is used as a means of emulating the effects on the device under study and the value of Rx is variable, it should be borne in mind that if for the section of the studied signal Ux with resistance Rx1 set the mode of changing the values E1 ′ ... E4 ′ in accordance with one of the four options discussed above (see relations (56), (57); (60), (61); (64), (65); (68), (69)), i.e. for a given value of Ux ′, then for a signal section with resistance Rx2, the values of Ux ′ and Uo ′ will change in accordance with relations (14), (19) and, accordingly, the value of the emulating effect Ux ′ on the device under study will differ from the specified in the signal section with resistance Rx1 (it is assumed that Rx is independent of Ux ′).

Frequency and duty cycle of switching reference sources 2,3; 14.15; 21.22; 27.28 and, accordingly, the frequency and duty cycle of emulating effects on the device under study can change according to the signals from the control unit 12.

Along with the emulating effect on the device under study, Ux ′, the device under study can also be affected by the constant component of the voltage drops of the reference sources 2,3; 14.15; 21.22; 27.28 at the input terminals of the meter -Ux0. The determination of the values of the DC components of the voltage drops at the input terminals of the Ux0 meter and at the input of the Uo0 oscilloscope is carried out in accordance with relations (14), (19) when replacing the values of the increments E1 ′ ... E3 ′ with the values of the corresponding DC components of the voltage of the reference sources 2,3; 14.15; 21.22; 27.28. The polarity of the constant components is usually determined relative to the total output of the meter. The presence of a constant component - Ux0, formed by sources of reference voltages, can be used in the direct study of low-level signals that have a significant constant component.

Table 1 - continued U, E, R \ nn Formula (No. xxx) 33 34 35 36 Note Uo ′, V 19 (87) 3 1.5 3 1.5 Ux, V 12 6 12 6 Uo2 ′, V 16 (84) 3.058824 1.529412 -0.509804 -0.509804 Uo1 ′, V 15 (83) -0.509804 -0.509804 3.058824 1.529412 Uo3 ′, V 17 (85) -5.882353 E-02 -2.941176 E-02 0.509804 0.509804 Uo4 ′, V 18 (86) 0.509804 0.509804 -5.882353 E-02 -2.941176 E-02 E2 ′, V 6 3 -one -one E1 ′, V -2 -2 12 6 E3 ′, V -3 -1.5 26 26 E4 ′, V 13 13 -1.5 -0.75 Ux2 ′, V 10 (78) 0.2352941 0.1176471 -3.921569 E-02 -3.921569 E-02 Ux1 ′, V 9 (77) -3.921569 E-02 -3.921569 E-02 0.2352941 0.1176471 Ux3 ′, V 11 (79) -0.2352941 -0.1176471 2.039216 2.039216 Ux4 ′, V 12 (80) 2.039216 2.039216 -0.2352941 -0.1176471 Ux14 ′, V 2 2 0 0 Ux23 ′, V 0 0 2 2 Ux ′, V 14 (82) 2 2 2 2 Rx kOm one hundred one hundred one hundred one hundred

In the presence of a constant component of the voltage of the reference sources 2,3; 14.15; 21.22; 27.28 - Е0 and with a parametrically changing value of Rx (i.e., in the absence of a signal source Ux), the dependence Rx = F (t) will be displayed on the screen of the oscilloscope 1. The determination of the value of Rx at the selected points is performed in accordance with the derived relations.

After measuring the amplitude of the studied signal Ux and the active component in the output resistance of the source of the studied signals Rx, it is possible to calculate the total amplitude of the studied signal:

the active component of the current Ix = Ux / Rx and the active component of the power of the studied signal Px = IxUx (current values at the selected time instants), as well as the construction of the time-dependent dependencies Ux (t), Rx (t), Ix (t), Px ( t), which makes it possible to comprehensively assess the source of the studied signals.

When conducting temporary measurements (Figure 5), the labels of the zones are set on the controlled areas of the studied signal Ux, between which measurements are made. The reference levels of time parameters are set similarly to the procedures used in amplitude measurements. According to the signals of the control unit 12, synchronous switching of sources of reference voltages 2,3 is performed; 14.15; 21.22, 27.28, as well as continuously adjustable delay lines of 6.7. At the same time, the delay values of the delay lines are changed to 6.7 until the zone marks are combined on the original and shifted images of the studied signal Ux. The combination of zone labels can be performed at high sensitivity of the oscilloscope 1 and at “fast” sweeps. The magnitude of the delay difference, pre-calibrated delay lines 6.7 [3], corresponds to the value of the measured time parameter.

The main derived relations are significantly simplified if we take R19 = R20 = R26 = R32 = R32 = R33 = R34 = R, and are reduced to the following form:

- relation (1) for calculating the equivalent input resistance of the meter:

- relation (2) for calculating the voltage division coefficient of the studied signal Ux at the input of the oscilloscope:

- relation (3) for calculating Rx at E1 ′, E3 ′ ≠ 0; E2 ′, E4 ′ = 0:

- relation (4) for calculating Rx at E2 ′, E4 ′ ≠ 0; E1 ′, E3 ′ = 0:

- relation (5) for calculating Rx, for E2 ′, E3 ′ ≠ 0; E1 ′, E4 ′ = 0:

- relation (6) for calculating Rx, for Е1 ′, Е4 ′ ≠ 0; E2 ′, E3 ′ = 0:

- relations (9) ... (12) for calculating the quantities Ux1 ′, Ux2 ′, Ux3 ′, Ux4 ′:

- coefficient N (13):

- relation (14) for calculating the value of Ux ′:

- relations (15) ... (18) for calculating the quantities Uo1 ′, Uo2 ′, Uo3 ′, Uo4 ′:

- relation (19) for calculating the value of Uo1:

- relation (25), which determine, when measuring Rx, the conditions for mutual compensation of the effects of Ux1 ′, Ux2 ′, Ux3 ′, Ux4 ′ on the device under study and Uo1 ′, Uo2 ′, Uo3 ′, Uo4 ′ at the input of oscilloscope 1 (first option):

и

, при проведении измерений величины Rx в четырехкаскадном варианте:- expression (26), which determines the relationship of relations

and

, when measuring Rx in a four-stage version:

- relation (28), which determine, when measuring Rx, the conditions for mutual compensation of the effects of Ux1 ′, Ux2 ′, Ux3 ′, Ux4 ′ on the device under study and Uo1 ′, Uo2 ′, Uo3 ′, Uo4 ′ at the input of oscilloscope 1 (second option):

и

, при проведении измерений величины Rx в четырехкаскадном варианте:- expression (29), which determines the relationship of relations

and

, when measuring Rx in a four-stage version:

- relations (32), (33) when conducting amplitude measurements to determine the values of E1 ′, E3 ′, at which the compensation condition Ux ′ = 0 is constantly observed (the first option):

- relations (34), (35) when conducting amplitude measurements to determine the values of E1 ′, E3 ′ for a given value of Uo ′, Ux ′ = 0 and an arbitrary value of Rx:

- relations (38), (39) when conducting amplitude measurements to determine the values of E1 ′, E3 ′, at which the compensation condition Ux ′ = 0 is constantly observed (second option):

- relations (40), (41) when conducting amplitude measurements to determine the values of E2 ′, E4 ′ for a given value of Uo ′, Ux ′ = 0 and an arbitrary value of Rx:

- relations (44), (45) when conducting amplitude measurements to determine the values of E2 ′, E3 ′, at which the compensation condition Ux ′ = 0 is constantly observed (third option):

- relations (46), (47) when conducting amplitude measurements to determine the values of E2 ′, E3 ′ for a given value of Uo ′, Ux ′ = 0 and an arbitrary value of Rx:

- relations (50), (51) when conducting amplitude measurements to determine the values of E1 ′, E4 ′, at which the compensation condition Ux ′ = 0 is constantly observed (fourth option):

- relations (52), (53) when conducting amplitude measurements to determine the values of E1 ′, E4 ′ for a given value of Uo ′, Ux ′ = 0 and an arbitrary value of Rx:

- relations (56), (57) for determining the values of E2 ′, E4 ′ when conducting amplitude measurements combined with emulating the effects on the device under study, for a given value of Ux ′ and a constant value of Rx (first option):

- relations (60), (61) for determining the values of E1 ′, E3 ′ when performing amplitude measurements combined with emulating the effects on the device under study, for a given value of Ux ′ and a constant value of Rx (second option):

- relations (64), (65) for determining the values of E1 ′, E4 ′ when conducting amplitude measurements combined with emulating the effects on the device under study, for a given value of Ux ′ and a constant value of Rx (third option):

- relations (68), (69) for determining the values of E2 ′, E3 ′ when conducting amplitude measurements combined with emulating the effects on the device under study, for a given value of Ux ′ and a constant value of Rx (fourth option):

The meter can be implemented as a stand-alone, functionally complete device or as a modular measuring complex, which includes a typical computer, a standard high-speed oscilloscope, additional devices connected to the measuring input of the oscilloscope, synchronization input of the oscilloscope, input of the labeling channel, and to one of the standard computer interfaces such as USB, as well as application software. The implementation of the meter in the form of a modular measuring complex allows you to minimize hardware costs. To ensure the logic of the meter, synchronize all units and connect to standard computer interfaces, it seems advisable to use programmable logic or typical microcontrollers as part of the control unit.

DAC circuits can be used as sources of reference voltage; to reduce digital “noise” due to race of fronts, gating circuits can be used for the difference in the time of establishing a DAC.

The input part of the meter should be implemented as a specialized custom LSI.

Measuring instruments for studying fast processes, such as stroboscopic oscilloscopes, are an indispensable tool in the development, debugging, and serial production of highly reliable electronic equipment. A large number of such products from leading manufacturers, implemented as finished devices with appropriate hardware and software, are currently on the market. At the same time, the price of these products is very high (up to several million rubles), which limits the possibility of their widespread use.

An alternative to using expensive stand-alone measuring devices can be a switch to technologies similar to those used in rapidly growing cloud computing services. At the same time, it is possible to reduce hardware costs, which are implemented as relatively inexpensive additional devices for typical computers with basic software, as well as increase mobility, the safety of measurements and calculations (creating a virtual measuring environment), similarly, for example, Intel’s concept of creating Cloud computing environments - Open Data Center. It is possible to quickly download application software from virtual servers as needed, where you can also store the results of measurements and information processing (providing virtual resources from a catalog, creating private clouds and combining them with public clouds to create hybrid clouds).

According to the invention, a mock meter was developed.

The values of the communication resistors R19, R20, R26, R32, R33, R34 were chosen equal to 1000 kOhm. The range of voltage levels of the reference sources 2.3; 14.15; 21.22; 27.28 was ± 30V. Accuracy of measuring voltage differences of voltage reference sources 2.3; 14.15; 21.22; 27.28 was 0.1%. The error in combining the signals on the oscilloscope screen was 5 mV and was determined by the sensitivity of the oscilloscope 1, noise, and instability of the images of the studied signals. The switching frequency of the reference voltage sources and delay lines varied from units of hertz to 1 kHz. The tuning range of the delay differences of the continuously adjustable delay lines of 6.7 was 0-1 μs, the error in the calibration of the delay lines was: ± 10 ^-5 Tx + 10 nc, where Tx is the value of the delay difference of the adjustable delay lines of 6.7.

The layout was used in tests of high-speed integrated circuits.

The present invention can be used:

- when creating aggregated measuring systems with enhanced functionality and increased accuracy, including standard measuring instruments, specialized hardware and software modules, typical PCs.

Various types of oscilloscopes, strobvoltmeters, including those with high speed, can be used as SSI.

Aggregated measuring systems are necessary for research and testing of high-speed electronic products of various classes. The use of SSI and standard PCs as a part of complexes allows minimizing the costs of their creation;

- when creating high-speed testers for parametric control and testing of VLSI, VLSI, and functional units of on-board computer systems. The solution to the problem of parametric control of the element base of computer systems can improve the reliability of radio-technical systems of telecontrol, air traffic control, navigation and landing;

- when creating parametric analyzers-emulators of system highways of on-board computer systems.

The widespread use of the backbone-modular principle of constructing on-board computer systems makes the problem of parametric control of system bus tires an urgent task when creating highly reliable radio systems;

- in medicine, in reflexology;

- in the energy sector.

The most effective use of the present invention when creating highly integrated high-speed on-board computer systems for air traffic control, navigation and landing. Increasing requirements for the reliability of airborne electronic systems lead to the need to increase the accuracy characteristics of the used measuring instruments, expanding their functional capabilities when conducting complex research, as well as when including measuring instruments in various information-measuring systems, semi-natural modeling complexes, and automated design stations.

The relevance of this problem is due to the interconnection of parametric and functional identifications of LSIs of onboard computers and system highways of radio engineering systems (RTS).

This relationship allows us to predict the occurrence of functional failures of the RTS, with adverse combinations of technological, climatic and operational factors, as well as provide measures to reduce the likelihood of parametric and functional failures and, accordingly, increase the reliability of the RTS.

A positive effect from the use of the invention arises:

- as a result of increasing the accuracy of amplitude measurements and, as a result, increasing the reliability of research results, increasing the reliability of electronic systems or increasing the yield of tested electronic devices when using the proposed device in industry;

- as a result of expanding the functionality of oscilloscope meters in the complex research and testing of various electronic devices;

- as a result of automation capabilities of the measurement process.

Information sources

1. USSR Copyright Certificate No. 599217, cl. GOIR 13/30, claimed 12/03/76 g.

2. Copyright certificate of the USSR No. 815641, cl. GOIR 13/30, claimed 06/22/79

3. USSR author's certificate No. 575618, cl. G04F 10/04 claimed 06/07/76

4. Application for the grant of a patent for an invention No. 2012113266, decl. 03/30/2012

Claims (1)

An oscillographic meter of amplitude characteristics of electrical signals, containing an oscilloscope, the first output of which is connected to the first input of the zone level forming unit, the second output is to the first input of the zone pulse generator, the output of which is connected to the backlight of the oscilloscope and the second input of the zone level forming unit, and the second input the zone pulse generator is connected to the third output of the control unit, the first output of which is connected to the third input of the zone level shaper, the second output to the WTO control input of the first switch, and the fourth output is with the control input of the first switch, the output of which is connected to the first output of the coupling capacitor, and the first and second inputs are to the first outputs of the first and second voltage reference sources, the second outputs of which are connected to the inputs of the voltage difference meter, and the inputs - with the second output of the coupling capacitor, the inputs of the first and second continuously adjustable delay lines connected to the synchronization input of the meter, and the outputs to the first and second inputs of the second switch, the output of which it is connected to the synchronization input of the oscilloscope, and the first and second outputs of the zone leveling unit are connected to the inputs of the voltage equalization indicator, while the first output of the additional coupling capacitor is connected to the second input of the oscilloscope, the first output of the second communication resistor and the output of the third switch, and the second output to the output of the first switch, the first output of the first communication resistor and the inputs of the third and fourth sources of reference voltage, the second outputs of which are connected to the inputs of an additional measurement voltage difference, and the first outputs with the first and second inputs of the third switch, the control input of which is connected to the fifth output of the control unit, the second terminals of the coupling resistors connected to the first input of the oscilloscope, while the first terminal of the fourth coupling capacitor is connected to the second terminal of the third coupling capacitor , the first output of the fourth communication resistor, the output of the fifth switch and the inputs of the fifth and sixth sources of reference voltage, the second outputs of which are connected to the inputs of the third meter voltage differences, and the first outputs with the first and second inputs of the fourth switch, the control input of which is connected to the sixth output of the control unit, the first output of the third communication resistor connected to the first output of the third communication capacitor and the output of the fourth switch, while the second output of the fourth communication capacitor connected to the second input terminal of the meter and the inputs of the seventh and eighth sources of reference voltage, the second outputs of which are connected to the inputs of the fourth meter of the voltage difference and the first outputs with the first and second inputs of the fifth switch, the control input of which is connected to the seventh output of the control unit, characterized in that in order to improve the accuracy it is equipped with fifth and sixth coupling resistors, while the second terminal of the first coupling capacitor is connected to the first terminal of the sixth a communication resistor, the second output of which is connected to the first input of the oscilloscope and the first output of the fifth communication resistor, the second output of which is connected to the first input terminal of the meter and the second conclusions of the third and fourth connection of resistors, and a second input of the oscilloscope connected to the second input terminal of the meter.

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