RU2582556C1 - Functional quadrature signal generator - Google Patents

Abstract

FIELD: electronics.

SUBSTANCE: invention relates to electronics and can be used in measurement techniques and automation. Function generator includes three multipliers (1-3), two integrators (4, 5), three squaring devices (6-8), two adders (9, 10) and a relay element 11, third 12 and fourth 13 adders, second relay element 14, fourth squaring device 15 and fourth multiplier 16.

EFFECT: technical result is broader functional capabilities of device by producing at its outputs quadrature harmonic signals and quadrature signals of bipolar rectangular and triangular shapes with high metrological characteristics when frequency is varied over a wide range.

1 cl, 4 dwg

Description

The invention relates to the field of electronics and can be used in measuring equipment and automation.

A device is known [Shustov M. Functional generator. - Radiomir, 2010, No. 7, p. 26-27], containing a source of quadrature signals, two half-wave rectifiers, an adder and a shaper of bipolar rectangular pulses, and the first and second outputs of the source of quadrature signals are connected respectively to the inputs of the first and second half-wave rectifiers, the outputs of which are connected to the inputs of the adder, the output of which is connected shaper of bipolar rectangular pulses, while the first, second and third outputs of the functional generator are connected respectively to the first output of the source quadrature signals, with the output of the adder and the output of the shaper of bipolar rectangular pulses.

The synthesized signal of a triangular shape has S-shaped characteristics both in the forward stroke section (linearly increasing voltage) and in the reverse stroke section (linearly decreasing voltage) and has a very low linearity [Lozitsky S. Circuit CAD systems: possibilities and problems of efficient use. Circuitry, 2007, No. 3, p. 38-40], which significantly narrows the scope of the practical application of the scheme. In addition, the frequency of a triangular waveform and a rectangular bipolar waveform is twice the frequency of the original harmonic signal, which makes it impossible to obtain the same frequency values at all generator outputs with a fixed tuning of the generator. It should also be borne in mind that the formation of a “quasilinear” signal of a triangular shape requires quadrature harmonic signals, which, under conditions of frequency tuning over a wide range, also causes certain difficulties.

A device is known [Titz U., Schenk K. Semiconductor circuitry: a reference guide. - M .: Mir, 1982, p. 307, fig. 18.25], containing a triangular waveform generator, the first output of which is connected to the output terminal of the relay function, and the second output is connected to the output terminal of the linear function and to the input of the functional converter, the output of which is connected to the output terminal of the sinusoidal function. In modern functional generators for generating a harmonic signal from a triangular waveform, the most widely used are diode functional converters, as well as converters using the I – V characteristics of field-effect transistors, which are based on the principle of piecewise-linear or piecewise-nonlinear approximation of the voltage of a sinusoidal shape. However, the whole range of basic requirements (low harmonic coefficient, the absence of a constant component in the sine wave signal, a wide range of operating frequencies, low accuracy of reproduction of the sine function when the temperature and supply voltages change, etc.) is quite difficult to ensure when using such functional converters [Dubrovin V.S., Nikulin V.V. A method of constructing controlled functional generators. T-comm, 2013, p. 22].

The closest device to the claimed invention for the combination of essential features is taken as a prototype controlled generator [US Pat. No. 2506692 Russian Federation, IPC ⁷ Н03В 27/00. Managed Generator / Dubrovin BC, Applicant and Patent Holder Dubrovin Viktor Stepanovich. - No. 2012137334/08; declared 08/31/12; publ. 02/10/14, Bull. No. 4], which contains two multipliers, two integrators, a relay element, an adder and a control unit, while the output of the first integrator is connected to the first input of the second multiplier, the input of the relay element, the first input of the control unit and the first output of the controlled generator, the output of the second integrator is connected with the second output of the controlled generator, the second input of the control unit and the second input of the adder, the output of which is connected to the first input of the first multiplier, the second input of which is connected to the control bus the generator and the second input of the second multiplier, the outputs of the first and second multipliers being connected respectively to the inputs of the first and second integrators, the third and fourth inputs of the control unit are connected respectively to the output of the relay element and the reference voltage bus, and the output of the control unit is connected to the first input of the adder.

The control unit is made of three quadrators, an adder, a multiplier, a limiter and an inverter, while the first, second and third inputs of the adder are connected, respectively, to the outputs of the first, second quadrators and to the inverter output, the input of which is connected to the output of the third quadrator, the first one the second and third inputs of the control unit are connected respectively to the inputs of the first, second and third quadrators, the fourth input of the control unit is connected to the second input of the multiplier, the first input of which is connected to the output of the adder, ezhdu whose output and the output control unit included limiter.

The device is designed to generate quadrature harmonic signals.

The task to which the invention is directed is to expand the functionality of the device and to obtain quadrature harmonic signals, as well as quadrature and triangular quadrature bipolar signals with high metrological characteristics when the frequency changes over a wide range, at its outputs.

The technical result achieved by the implementation of the invention is to expand the functionality of the proposed device by introducing a third and fourth adder, a second relay element, a fourth quadrator and a fourth multiplier and the organization of new connections between the elements, which made it possible to obtain quadrature harmonic signals at its outputs, and also quadrature bipolar signals of rectangular and triangular shape with high metrological characteristics when changing frequency widely.

The specified technical result in the implementation of the invention is achieved by the fact that in the functional generator of quadrature signals containing three multipliers, two integrators, three quadrators, two adders and a relay element, the output of which is connected to the second input of the third multiplier, the first input of which is connected to the output of the second adder, the first input of which is connected to the output of the first quadrator, the input of which is connected to the output of the first integrator, the input of which is connected to the output of the first multiplier, the second input to The second one is connected to the control bus and the second input of the second multiplier, to the output of which the input of the second integrator is connected, the output of the second quadrator is connected to the second input of the second adder, the third input of which is connected to the voltage reference bus, the first, second and third outputs of the functional generator are connected with outputs of the first integrator, relay element and third multiplier, respectively, the third and fourth adders, the second relay element, the fourth quadrator and the four are additionally introduced the second multiplier, the first input of which is connected to the output of the fourth adder, the third input of which is connected to the voltage reference bus, and the first input - to the output of the third quadrator, between the output of which and the second input of the fourth adder the fourth quadrator is connected, while the output of the second integrator is connected to the input the third quadrator and the second input of the third adder, the third input of which is connected to the first input of the second multiplier, the second input of the fourth multiplier and the output of the second relay element, the input of which the second is connected to the output of the third adder, the first input of which is connected to the output of the first integrator and the first input of the first adder, the output of which is connected to the input of the relay element, the output of which is connected to the second input of the first adder and the first input of the first multiplier, and the input of the second quadrator is connected to the output the first quadrator, and the fourth, fifth and sixth outputs of the functional generator of quadrature signals are connected to the outputs of the fourth multiplier, second relay element and second about the integrator.

The analysis of the prior art by the applicant, including a search by patent and scientific and technical sources of information, allowed to establish that the applicant did not find an analogue characterized by features identical to all the essential features of the claimed invention. Therefore, the claimed invention meets the condition of "novelty."

The introduction of the third and fourth adders, the second relay element, the fourth quadrator and the fourth multiplier into the proposed device, as well as the organization of new connections between the elements, made it possible to obtain quadrature harmonic signals, as well as rectangular and triangular quadrature bipolar signals with high metrological characteristics when changing frequencies over a wide range.

The invention is illustrated by the structural diagram of a functional generator of quadrature signals (Fig. 1) and graphs (Fig. 2 - Fig. 4), explaining the principle of operation of a functional generator of quadrature signals.

The functional quadrature signal generator (Fig. 1) contains four multipliers (1-3, 16), two integrators (4, 5), four quadrators (6-8, 15), four adders (9, 10, 12, 13) and two relay elements (11, 14), while the first relay element 11 is connected between the output of the first adder 11 and the first input of the first multiplier 1, between the output of which and the input of the first quadrator 6, the first integrator 4 is connected, the output of which is connected to the first input of the first adder 9 and the first input of the second adder 12, between the output of which and the first input of the second multiply The second relay element 14 is connected, the output of which is connected to the third input of the first adder 12, the second input of which is connected to the output of the second integrator 5, between the output of which and the input of the fourth quadrator 15 the third quadrator 8 is connected, the output of which is connected to the first input of the fourth adder 13 the third input of which is connected to the reference voltage bus and the third input of the second adder 10, the first input of which is connected to the output of the first quadrator 6, between the output of which and the second input of the second adder 10 a second quadrator 7, and the first input of the third multiplier 3 is connected to the output of the second adder 10, the second input of which is connected to the second input of the first adder 9 and the first input of the first multiplier 1, the second input of which is connected to the control bus and the second input of the second multiplier 2, to the output which is connected to the input of the second integrator 5, the output of which is connected to the sixth output of the functional generator of quadrature signals, the fifth output of which is connected to the output of the second relay element 14 and the second input of the fourth a multiplier 16, the first input of which is connected to the output of the fourth adder 13, the second input of which is connected to the output of the fourth quadrator 15, and the first, second, third and fourth outputs of the functional generator of quadrature signals are connected to the outputs of the first integrator 4, the first relay element 11, and the third multiplier 3 and the fourth multiplier 16.

Functional generator of quadrature signals operates as follows.

Multipliers 1 and 2, integrators 4 and 5, relay elements 11 and 14, as well as adders 9 and 10 form (Fig. 1) a controlled generator of quadrature signals of a triangular shape and bipolar signals of a rectangular shape.

The multiplier 1 and the inverting integrator 4 form a controlled integrator, the transfer function of which (in Laplace images) has the meaning:

where s is a complex variable; E _y - control voltage; τ ₁ is the time constant of the first integrator 4; m ₁ - scale factor multiplier 1; τ _y1 = τ ₁ / E _y - controlled time constant.

The multiplier 2 and the inverting integrator 5 form a second controlled integrator, the transfer function of which matters:

where s is a complex variable; τ ₂ is the time constant of the second integrator 5; m ₂ is the scale factor of the second multiplier 2; τ _U2 = τ ₂ / E _y - controlled time constant of the second controlled integrator.

When τ ₁ = τ ₂ = τ; m ₁ = m ₂ = m = 1 transfer functions of controlled integrators will also have the same values:

.Where

.

In the steady state (Fig. 2), the corresponding rectangular bipolar signals D ₁ (t) and D ₂ (t) are generated at the outputs of the first 11 and second 14 inverting relay elements, which are fed to the inputs of the corresponding controlled integrators.

At the output of the first controlled integrator, a triangular signal L ₁ (t) is generated (Fig. 2), and at the output of the second controlled integrator, a similar signal L ₂ (t) is shifted 90 degrees from the first one.

The first 9 and second 10 adders provide (Fig. 2) the formation of signals V ₁ (t) and V ₂ (t) received at the inputs of the corresponding relay elements 11 and 14, which provide stable amplitude values of the rectangular and triangular signals.

The amplitude values of D _m1 and D _m2 (Fig. 2) of the corresponding signals 2), (0 and D ₂ (t) are determined by the values of the limiting voltages U ₀₁ and U _{02 of the} corresponding relay elements 11 and 14.

With the equality U ₀₁ = U ₀₂ = U _{0, the} frequency f of the generated signals of triangular and rectangular shape is determined by the following expression:

whence it follows that the frequency f of the generated signals will linearly depend on the change in the control voltage E _y .

Squatters 6 and 7, adder 10 and multiplier 3 form (Fig. 1) the first harmonic signal shaper, and squares 8 and 15, adder 13 and multiplier 16 form the second harmonic signal shaper. Signals N ₁ (t) and N ₂ (t) are respectively supplied to the third and fourth outputs of the functional generator.

Consider the process of forming harmonic signals using the example of the second shaper (Fig. 3, b), since the process of forming the harmonic signal N ₁ (t) in the first shaper will occur in a similar way.

To find the analytical expressions of the signal L ₂ (t), we use the general expression for the straight line y = kx + b passing through two points with coordinates (x ₁ , y ₁ ) and (x ₂ , y ₂ ):

where x is the current value of the angle in radians.

Substituting in (1) the coordinates of the two boundary points [x ₁ = 0, y ₁ = -A; x ₂ = π, y ₂ = A] for the first section of the signal L ₂ (t), we obtain:

Substituting in (1) the coordinates of two other boundary points [x ₁ = π, y ₁ = A; x ₂ = 2π, y ₂ = -A] for the second section of the signal L ₂ (t), we obtain:

To simplify the argument, we assume that the amplitude values of the signal L ₂ (t) are equal to the normalized value A = A ^* = 1. In this case:

Consider the operation of the harmonic signal former in the first segment at x∈ [π; 2π]. At the output of the third 8 and fourth 15 quadrators, the corresponding signals are formed (Fig. 3, b):

The adder 13 is inverting, so a signal will be generated at its output:

where k ₄₁ , k ₄₂ and k ₄₃ are the transfer coefficients of the adder 13 at the corresponding inputs, E ₀ is the value of the reference voltage.

When k ₄₃ = 1, E ₀ = 1 and taking into account (5) we get:

For x = 0 and x = π (Fig. 3, b):

From equation (7) we find the relationship between the coefficients k ₄₁ and k ₄₂ :

Substituting the value of the coefficient k ₄₂ from equation (8) into equation (6), we obtain:

The maximum (extreme) value of M _{2 max} will be (Fig. 4, d) at x = π / 2:

Similar results can be obtained for the second section, with M ₂ (π) = M ₂ (2π) = 0, and M _{2 max} = M ₂ (3π / 2) = A ^* = 1.

Analysis of the curve M ₂ (x) shows that the signal is close in shape to a sinusoid, therefore, to estimate the error ε (x), we find the difference between the signal M ₂ (x) and M ₀ (x) for an ideal sinusoid:

moreover, as follows from (9), the magnitude of the error will depend on the value of the coefficient k ₄₁ .

The error s (x) is minimized when the coefficient k ₄₁ ≈1.2232, and the coefficient k ₄₂ ≈0.2232.

The formation of a harmonic signal N ₂ (x) occurs using a phase modulator made of a multiplier 16, the first input of which receives (Fig. 4, d) a unipolar signal M ₂ (x), and on the other (Fig. 4, d) - a control signal D ₂ (x) from the output of the second relay element 14.

Thus, at the output of the multiplier 16, a harmonic signal N ₂ (t) is formed, the distortion coefficient of which does not exceed 0.072% at optimal values of the coefficients k _41opt = 1.2232 and k _42opt = 0.2232. The optimization of coefficients and the measurement of nonlinear distortion were performed using the block (THD-Total harmonic distortion) of the PSIM 9 program.

Using the present invention will expand the functionality of the device and get at its outputs quadrature harmonic signals, as well as quadrature bipolar signals of rectangular and triangular shape with high metrological characteristics when the frequency changes over a wide range.

Claims (1)

A functional quadrature signal generator containing three multipliers, two integrators, three quadrators, two adders and a relay element, the output of which is connected to the second input of the third multiplier, the first input of which is connected to the output of the second adder, the first input of which is connected to the output of the first quadrator, the input of which connected to the output of the first integrator, the input of which is connected to the output of the first multiplier, the second input of which is connected to the control bus and the second input of the second multiplier, to the output of the cat the input of the second integrator is connected, the output of the second quadrator is connected to the second input of the second adder, the third input of which is connected to the reference voltage bus, the first, second and third outputs of the functional generator are connected to the outputs of the first integrator, relay element and third multiplier, respectively the fact that the third and fourth adders, the second relay element, the fourth quadrator and the fourth multiplier, the first input of which is connected to the output, are additionally introduced into it the fourth adder, the third input of which is connected to the voltage reference bus, and the first input - with the output of the third quadrator, between the output of which and the second input of the fourth adder the fourth quadrator is turned on, while the output of the second integrator is connected to the input of the third quadrator and the second input of the third adder, the third the input of which is connected to the first input of the second multiplier, the second input of the fourth multiplier and the output of the second relay element, the input of which is connected to the output of the third adder, the first input to It is connected to the output of the first integrator and the first input of the first adder, the output of which is connected to the input of the relay element, the output of which is connected to the second input of the first adder and the first input of the first multiplier, the input of the second quadrator connected to the output of the first quadrator, and the fourth, fifth and sixth the outputs of the functional generator of quadrature signals are connected to the outputs of the fourth multiplier, the second relay element, and the second integrator, respectively.

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