RU2463614C1 - BRIDGE GAUGE OF n-ELEMENT BIPOLES PARAMETERS - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: device contains a generator including linear, quadratic and cubic voltage pulse shapers, a commutator, a synchronisation unit and a power amplifier. The power amplifier output represents the generator first output; the synchronisation unit output represents the generator second output; the generator third output represents the bridge circuit second input. Connected to the generator is a four-armed bridge circuit consisting of two parallel loops. The first loop contains two bipoles, placed in series. The first bipole elements have constant parameters while the second bipole elements have adjustable parameters and are used for the bridge balancing. The first and second multi-element bipoles of the bridge circuit first loop contains an identical number of build-up circuits, each of the connected in parallel to the previous build-up circuit coil. The total number of build-up circuits is equal to the ratio of the number of elements in the measurement objects to 4. The bridge second loop contains, serially coupled. a standalone resistor and two terminals for connection of the bipoles of the measurement objects. The bridge circuit first output is represented by the common point of the first and the second multi-element bipoles of the bridge first loop while the second output is represented by the common point of one of the terminals and the standalone resistor of the second loop. The both bridge outputs are connected to the differential input of the null-indicator the second input whereof is connected to the synchronisation unit with the common bus grounded.

EFFECT: increasing the number of determined parameters of measurement objects.

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Description

The invention relates to information and measurement technology, automation and industrial electronics and can be used to control and determine the parameters of measurement objects, as well as physical quantities by means of parametric sensors.

A known parameter meter of n-element passive two-terminal [1], which contains a series-connected pulse generator with voltage change over their duration according to the law of power functions, a four-arm bridge circuit for determining resistive-capacitive parameters (R-C two-terminal and a zero indicator).

Its disadvantage is the inability to determine the parameters of resistive-inductive (R-L) two-terminal and two-terminal with dissimilar reactive elements (R-L-C).

Known bridge meter parameters of multi-element passive two-pole [2], containing a series-connected generator of voltage pulses that varies during their duration according to the law of power functions, four-arm bridge circuit and a zero indicator.

The disadvantage of this meter is the lack of advanced functionality, that is, it is not suitable for determining five, six or more parameters of multi-element two-terminal measurement objects.

The closest to the claimed device in terms of technical nature and the achieved result is a three-element passive two-terminal device selected as a prototype [3], which contains a series-connected pulse generator, a four-arm bridge circuit and a zero indicator.

The problem to which the invention is directed is to expand the functionality that the meter will allow you to determine four, five or more parameters of multi-element two-terminal devices, and it will also allow you to determine the parameters R-C, R-L and R-L-C of two-terminal objects of measurement.

This is achieved by the fact that in a bridge meter of parameters of n-element two-terminal devices containing a voltage pulse generator, which consists of voltage pulse shapers, which varies during their duration according to the law of an integer degree of time K ₀ t ⁰ , K ₁ t ¹ , K ₂ t ² , ..., K _n-1 t ^n-1 , where K _i are constant coefficients, t is time, n is the number of elements in the two-terminal network of the measurement object, switch, the inputs of which are connected to the outputs of the formers, and the output is connected to the input of the power amplifier, the output which forms the first output rel relative to the ground of the pulse generator (output of the power pulses), the synchronization unit, the output of which is connected to the synchronization inputs of each of the pulse shapers, and its output forms the second output of the generator relative to the ground (synchronization output); the first output of the pulse generator is connected to the input of the four-armed electric bridge, the first branch of which includes the first multi-element two-terminal, where the first resistor is connected to the capacitor and the other output of the first resistor is connected to the inductive coil, the common output of the first resistor and capacitor is connected to the first output of the pulse generator and the common output of the first resistor and inductive coil forms the first output terminal of the four-arm bridge circuit; parallel to the first branch of the bridge, its second branch is included, consisting of a single resistor in series and two terminals for connecting two-terminal measuring objects, the common output of a single resistor and the first terminal form the second output terminal of the bridge circuit; the free output of a single resistor is connected to the first output of the pulse generator, and the second terminal to ground; a null indicator, to the differential input of which two outputs of the bridge circuit output are connected, and to the synchronization input - the second output of the pulse generator, the common bus of the null indicator is grounded, an additional (second) resistor, a second, third, etc. are introduced. the same extension circuit, and the first branch of the bridge circuit consists of two multi-element bipolar terminals connected in series, identical in number of elements, their composition and inclusion, an additional (second) resistor is connected to the free output of the capacitor of the first multi-element bipolar first branch of the bridge and the free output of the inductive coil the two-terminal network of the first resistor, capacitor, second (additional) resistor and inductive coil forms the first build-up circuit, the total number of equal extension chains is the quotient of dividing the number n by four (n / 4), if n is divided by four without remainder, in which case the last extension chain is complete, if n is divided by four with a remainder, then the number of extension chains is an integer part of the private (n / 4) plus the unit and the last extension circuit is incomplete and consists of the first resistor, capacitor and second resistor, while the free output of the second resistor is connected to the common output of multi-element bipolar terminals of the first branch of the bridge, or the last chain It consists of the first resistor and capacitor, while the free output of the capacitor is connected to the common terminal of the multi-element two-terminal devices of the first branch of the bridge, and finally, the last extension circuit can consist of only one first resistor, the total number of elements in the first multi-element two-terminal device of the first branch of the bridge is equal to the number elements in the bipolar of the measurement object, each subsequent (second, third, etc.) extension circuit is connected in parallel with the inductive coil of the previous extension circuit, free in the output of the second multi-element bipolar of the first branch of the bridge is grounded, the number of formers in the pulse generator supplying the bridge circuit is equal to the number n of elements in the bipolar of the measurement object.

The invention is illustrated in the drawing.

The bridge meter of the parameters of n-element two-terminal devices contains a voltage pulse generator 1, which includes n voltage pulse shapers, which varies during their duration according to the law of an integer degree of time: voltage shaper 2 K ₀ t ⁰ , voltage shaper 3 K ₁ t ¹ , shaper 4 voltages K ₂ t ² , etc., where K _i are constant coefficients, t is time, the outputs of the formers are connected to the inputs of the switch 5, the output of which is connected to the input of the power amplifier 6. The output of the synchronization unit 7 is connected to synchronization inputs of each of the pulse shapers. The first branch of the four-arm bridge electric circuit consists of two series-connected multi-element two-terminal devices. The first of them contains a first resistor 8 (R8), in parallel with which are connected in series a capacitor 9 (C9), a second resistor 10 (R10) and an inductor 11 (L11). Elements 8, 9, 10, and 11 have constant parameters. The second multi-element two-terminal is made according to a circuit similar to the (identical) scheme of the first two-terminal, and consists of a first resistor 12 (R12), in parallel with which are connected in series a capacitor 13 (C13), a second resistor 14 (R14) and an inductor 15 (L15). Elements 12, 13, 14 and 15 have adjustable parameters and are used to balance the bridge. The second branch of the bridge circuit contains a single resistor 16 (R16) connected in series and two terminals for connecting two-terminal measuring objects. The common terminal of the first resistor 8 and capacitor 9 of the first multi-element bipolar of the first branch of the bridge is connected to the free terminal of a single resistor 16 of the second branch, and they form the input of the bridge circuit, which is connected to the output of the amplifier 6 of the pulse generator power. The common terminal of the first resistor 8 and the inductance coil 11 of the first multi-element bipolar and the first resistor 12 and the capacitor 13 of the second multi-element bipolar of the first branch of the bridge circuit form the first output terminal of the bridge circuit, and the common terminal of the single resistor 16 of the second branch and the first terminal for connecting measurement objects forms the second bridge circuit output terminal (differential bridge output), both bridge circuit output terminals are connected to the differential input of the null indicator 17, the synchronization input of which dklyuchen to the second output pulse generator common bus null indicator 17 is grounded. A two-terminal network formed in parallel by a first resistor 18 and a circuit consisting of a series-connected capacitor 19, a second resistor 20 and a coil 21 is a second extension circuit for the first multi-element two-terminal network; it is connected in parallel to the coil 11. Similarly, the circuit formed in parallel by the first resistor 22 and connected in series by the capacitor 23, the second resistor 24 and the inductor 25, is the second build-up circuit for the second multi-element bipolar; it is connected parallel to coil 15. Elements 22, 23, 24 and 25 have adjustable parameters and serve to balance the bridge.

The first and second multi-element two-terminal circuits of the first branch of the bridge circuit in the general case contain several extension chains. Each subsequent extension circuit is connected in parallel with the inductive coil of the previous extension circuit. The total number of identical extension chains is equal to the quotient of dividing the number n by four (n / 4), if n is divided by four without a remainder, in which case the last extension chain is complete. If n is divided by four with a remainder, then the number of extension chains is equal to the integer part of the quotient (n / 4) plus one and the last extension chain is incomplete. It can consist of a first resistor, a capacitor, and a second resistor, the free output of which is connected to the first output of the bridge circuit output. The last extension circuit may consist of a first resistor and a capacitor, the free output of which is connected to the first output terminal of the bridge. And finally, the last extension circuit may contain only one first resistor. The total number of elements in each of the two multi-element two-terminal devices in the first branch of the bridge is equal to the number of elements in the two-terminal device of the measurement object. Also, this number is equal to the number of shapers in the pulse generator.

For example, there are three options for two-terminal measurement objects:

1) resistive-capacitive (R-C) two-terminal device, which consists of a first resistor 26 (R26), in parallel with which the first capacitor 27 (C27) and the second resistor 28 (R28) are connected in series, the second capacitor 29 (C29) is connected in parallel with the resistor 28;

2) a resistive-inductive (R-L) two-terminal device, which consists of a series-connected resistor 30 (R30) and a first inductor 31 (ZJ7), in parallel with which a second resistor 32 (R32) and a second inductor 33 (L33) are connected in series;

3) a two-terminal device with heterogeneous reactive elements (R-L-C), which consists of a first resistor 34 (R34), in parallel with which a capacitor 35 (C35), a second resistor 36 (R36) and an inductor 37 (L37) are connected in series.

Let us explain the operation of the meter. As in the well-known bridge chains, elements 8, 9, 10, 11, 18, 19, 20 and 21, as well as element 16 are exemplary elements with known constant values of parameters of increased accuracy and stability. Elements 12, 13, 14, 15, 22, 23, 24, and 25 are exemplary adjustable elements with known parameter values for balancing the electrical bridge circuit. Elements 26, 27, 28 and 29 R-C of a two-terminal device, 30, 31, 32 and 33 R-L of a two-terminal device and, finally, 34, 35, 36 and 37 R-L-C of a two-terminal device are elements of measuring objects with unknown parameter values.

At each measurement stage, at the beginning of the supply pulse and after its end, transient processes occur in the bridge circuit in the form of voltage surges, which eventually decay to zero according to the exponential law. Useful for measurements is the portion of the bridge output pulse in the time interval from the end of the transient to the end of the supply pulse. In this section of the pulse, the flat top of the pulse voltage of the disequilibrium at the output of the bridge leads to zero. Consider the operation of a bridge meter when a resistive-capacitive (RC) two-terminal device of the measurement object R ₂₆ -C ₂₇ -R ₂₈ -C _{29 is} connected to it. First, a sequence of rectangular pulses is fed to the bridge circuit from the output of amplifier 6. When the next pulse of rectangular voltage is applied to the bridge after the end of the transition process in the bridge circuit and until the moment of the end of the pulse supplying the bridge, the nonequilibrium voltage, which is supplied to the zero indicator 17, has a flat top. The voltage of this flat top depends, inter alia, on the ratio of the resistance values of the resistors 8 (R ₈ ) and 12 (R ₁₂ ). By adjusting the resistance value R ₁₂ in a two-terminal network with balancing elements, the nonequilibrium voltage leads to zero and, therefore, the first condition for the equilibrium of the bridge circuit is fulfilled

The zero value of the voltage of the flat peak is noted by the zero indicator 17, for which, for example, an oscilloscope can be used. The count of the unknown resistance R _{26 of the} resistor 26 is taken from expression (1), in which all other values are known.

After that, a linearly varying voltage pulse is supplied to the bridge circuit from the output of the generator 1. When the next pulse is applied after the end of the transition process, the pulse output voltage of the bridge supplied to the zero indicator 17 has a flat top. Its voltage depends, inter alia, on the parameters R _{12 of the} resistor 12 and C _{13 of the} capacitor 13 of the two-terminal network with balancing elements of the bridge. By adjusting the capacitance value C _{13, the} voltage of the flat top is brought to zero and the second equilibrium condition is fulfilled

A zero value is indicated by the zero indicator 17. Do not adjust the resistance value R ₁₂ , as this will lead to a violation of the equilibrium condition (1), which is unacceptable. The reference value of the unknown parameter C ₂₇ (capacitor capacitance 27) is taken from expression (2), since the remaining values in it are known, including the resistance value R ₂₆ from expression (1).

Next, a quadratic pulse is supplied to the bridge circuit from the output of the generator 1. When the next pulse is applied after the end of the transition process, the pulse output voltage of the bridge supplied to the zero indicator 17 has a flat top. Its voltage depends, inter alia, on the capacitance C _{13 of the} capacitor 13 and the resistance R _{14 of the} resistor 14 of the two-terminal network with balancing elements of the bridge. Parameter C _{13 was} already used earlier to balance the bridge, and its value cannot be changed, as the fulfillment of the previous equilibrium conditions is violated. There remains the parameter R ₁₄ , which previously was not included in the equilibrium conditions (1) and (2), and by adjusting its values, the voltage of the flat top is brought to zero, noting this by the zero indicator 17. As a result, the third equilibrium condition is satisfied

From expression (3), a reference is taken to the value of the unknown parameter R ₂₈ (resistance of resistor 28), since the remaining values in it are known, including the resistance value R ₂₆ from expression (1) and capacitance C ₂₇ from expression (2).

At the next, fourth, stage, cubic pulses are supplied to the bridge circuit from the generator. When the next pulse is applied after the end of the transition process, the pulse output voltage of the bridge supplied to the zero indicator 17 has a flat top. Its voltage depends, inter alia, on the resistance R _{12 of the} resistor 12, the capacitance C _{13 of the} capacitor 13, the resistance R _{14 of the} resistor 14 and the inductance L _{15 of the} coil 15 of the two-terminal network with balancing elements of the bridge circuit. Previously, R ₁₂ , C ₁₃ and R ₁₄ were used for balancing, so their values should not be changed, as the previous equilibrium conditions will cease to be satisfied. There remains the parameter L ₁₅ , which was not included in the previous equilibrium conditions (1) - (3), and by adjusting its values, the voltage of the flat top is brought to zero, this is indicated by the zero indicator 17. For an example, three stages of balancing are considered in detail and the fourth stage. Further, at the subsequent stages of balancing, power pulses with a change in voltage are used according to the laws of the fourth, fifth, etc. degrees. The number of balancing stages and the number of used forms of supply pulses is equal to the number of parameters in the two-terminal objects of measurement. At each stage, the flat peak of the nonequilibrium voltage is reduced to zero in the time interval from the end of the transition process to the end of the supply pulse. This is done by adjusting the parameter of the balancing element, which was not used in the previous stages of balancing and was not included in the previous equilibrium conditions. In particular, on the fifth, sixth, seventh, etc. stages of balancing sequentially used elements 22 (resistance R ₂₂ ), 23 (capacity C ₂₃ ), 24 (resistance R ₂₄ ), etc.

From the above statements it follows that at each stage of balancing only one of the balancing parameters changes, and only one of the equilibrium conditions is satisfied (A _i = 0). Thus, the balancing of the bridge chain is separate dependent.

When connecting other bipolar measurement objects to the bridge circuit, all the above operations are repeated. So, for the RL bipolar of the measurement object R ₃₀ -L ₃₁ -R ₃₂ -L ₃₃ , the same forms of supplying pulse signals, the same adjustable parameters and the previous procedure for regulating their values are saved: R ₁₂ , C ₁₃ , R ₁₄ , .... We give the equilibrium conditions for the first three stages:

Of these, a reading of the values of the desired parameters is taken: resistance R _{30 of} resistor 30, inductance L _{31 of} coil 31 and resistance R _{32 of} resistor 32.

When connecting a two-terminal device with heterogeneous reactive elements R ₃₄ -C ₃₅ -R ₃₆ -L ₃₇ to the RLC bridge circuit, use the same adjustable parameters and the procedure for regulating their values: R ₁₂ , C ₁₃ , R ₁₄ , .... We give the equilibrium conditions for the first three stages:

Of these, a reading of the values of the desired parameters is taken: resistance R _{34 of the} resistor 34, capacitance C _{35 of the} capacitor 35 and resistance R _{36 of the} resistor 36.

Thus, the use of extension circuits in multi-element bridge diodes with exemplary and adjustable elements significantly expands the functionality of the bridge meter and allows you to determine the parameters RC, RL and RLC of the two-terminal measurement objects with an n-element equivalent circuit, where the number n of measured parameters can be five, six or more. At the same time, the bridge chain retains such an important property as separate balancing.

Information sources

1. USSR author's certificate No. 1150556, G01R 17/10. Bridge meter parameters n-element passive two-terminal / G.I. Peredelsky, publ. 1985, Bull. No. 14 (analog).

2. RF patent No. 2365921, G01R 17/00. Bridge meter of parameters of passive two-terminal / G.I. Peredelsky, V.I. Ivanov, publ. 2009, Bull. No. 24 (analogue).

3. USSR Author's Certificate No. 798606, G01R 17/10. Bridge meter parameters of three-element passive two-terminal / G.I. Peredelsky, publ. 1981, Bull. No. 3 (prototype).

Claims (1)

A bridge meter of n-element two-terminal parameters, comprising a voltage pulse generator, which consists of voltage pulse shapers that vary over their duration according to the law of an integer time degree K ₀ t ⁰ , K ₁ t ¹ , K ₂ t ² , ..., K _{n- 1} t ^n-1 , where K _i are constant coefficients, t is time, n is the number of elements in the two-terminal network of the measurement object, the switch, the inputs of which are connected to the outputs of the formers, and the output is connected to the input of the power amplifier, the output of which forms the first output relative to the ground generator and pulses (output of power pulses), a synchronization unit, the output of which is connected to the synchronization inputs of each of the pulse shapers, as well as its output forms the second output of the generator relative to the ground (synchronization output); the first output of the pulse generator is connected to the input of the four-armed electric bridge, the first branch of which includes the first multi-element two-terminal, where the first resistor is connected to the capacitor and the other output of the first resistor is connected to the inductive coil, the common output of the first resistor and capacitor is connected to the first output of the pulse generator and the common output of the first resistor and inductive coil forms the first output terminal of the four-arm bridge circuit; parallel to the first branch of the bridge, its second branch is included, consisting of a single resistor in series and two terminals for connecting two-terminal measuring objects, the common output of a single resistor and the first terminal forms the second output terminal of the bridge circuit; the free output of a single resistor is connected to the first output of the pulse generator, and the second terminal to ground; a zero indicator, to the differential input of which two outputs of the bridge circuit output are connected, and to the synchronization input - the second output of the pulse generator, the common bus of the zero indicator is grounded, characterized in that an additional (second) resistor, second, third, etc. .d. the same extension circuit, and the first branch of the bridge circuit consists of two multi-element bipolar terminals connected in series, identical in number of elements, their composition and inclusion, an additional (second) resistor is connected to the free output of the capacitor of the first multi-element bipolar first branch of the bridge and the free output of the inductive coil the two-terminal network of the first resistor, capacitor, second (additional) resistor and inductive coil forms the first build-up circuit, the total number of equal extension chains is the quotient of dividing the number n by four (n / 4), if n is divided by four without remainder, in which case the last extension chain is complete, if n is divided by four with a remainder, then the number of extension chains is an integer part of the private (n / 4) plus one, and the last extension circuit is incomplete and consists of the first resistor, capacitor and second resistor, while the free output of the second resistor is connected to the common output of multi-element bipolar terminals of the first branch of the bridge, or the last circuit It consists of the first resistor and capacitor, while the free output of the capacitor is connected to the common terminal of the multi-element two-terminal devices of the first branch of the bridge, and finally, the last extension circuit can consist of only one first resistor, the total number of elements in the first multi-element two-terminal device of the first branch of the bridge is equal to the number elements in the bipolar of the measurement object, each subsequent (second, third, etc.) extension circuit is connected parallel to the inductive coil of the previous extension circuit, free A output of the second multi-element two-pole earthed first branch of the bridge, the number of generators in the pulse generator feeding the bridge circuit is equal to the number n of elements in the two-terminal network measurement object.