RU2538946C1 - Bridge measuring device of parameters of bipoles - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: bridge measuring device of parameters of bipoles includes an in-series connected generator of feed pulses with variation of voltage during their duration as per a law of power functions, a four-arm bridge circuit and a zero indicator. To the bridge circuit there introduced are three additional resistors, an additional capacitor, and an additional inductance coil and in-series connected is the first additional resistor, an additional capacitor, the second additional resistor and an additional inductance coil. A free terminal of the first additional resistor is connected to the second terminal of the bridge circuit output; a free terminal of the additional inductance coil is earthed; the third additional resistor is connected between the common terminal of the first resistor, the inductance coil and the capacitor and the common terminal of the first additional resistor and the additional capacitor. An unearthed terminal of the available second resistor is connected to the common terminal of the available first resistor, the inductance coil, the capacitor and the additional third resistor, and the free terminal of the capacitor is earthed.

EFFECT: enlarging functional capabilities.

1 dwg

Description

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

Known bridge meter parameters of passive bipolar [USSR Author's Certificate No. 1150555, MKI G01R 17/10. BI 1985, No. 14 (analogue)], containing a pulse generator with voltage changing in series during the pulse duration according to the law of power functions, a four-arm bridge electric circuit and a zero indicator.

Its disadvantage is the inability to determine the values of the parameters of resistive-capacitive (R-C) bipolar and bipolar with heterogeneous (R-L-C) reactive elements.

Known meter parameters of multi-element passive bipolar [USSR Author's Certificate No. 1157467, MKI G01R 17/10. BI 1985, No. 19 (analogue)], containing a pulse generator with voltage change in series during the pulse duration according to the law of power functions, a four-arm bridge electric circuit and a zero indicator.

Its disadvantage is the inability to determine the parameter values of resistive-inductive (R-L) two-terminal and resistive-capacitive (R-C) two-terminal.

The closest in technical essence and the achieved result to the claimed device is a bridge meter of parameters of four-element passive two-terminal devices selected as a prototype [USSR Author's Certificate No. 918862, MKI G01R 17/10. BI 1982, No. 13 (prototype)], containing a trapezoidal pulse generator, a four-arm bridge circuit and a zero indicator connected in series.

Its disadvantage is the inability to determine the parameter values of resistive-inductive (R-L) two-terminal and resistive-capacitive (R-C) two-terminal.

The problem to which the invention is directed, is to expand the functionality, namely, that the meter will allow you to determine the parameters R-C, R-L and R-L-C of the two-pole measuring objects when they are connected to the same two terminals of the bridge circuit.

This is achieved by the fact that in a bridge meter of two-terminal parameters, it contains a pulse generator that generates pulse sequences of rectangular, linearly changing, quadratic and cubic shapes (u _i = K _i t ⁱ , where u _i is the change in voltage in the pulse, K _i are constant coefficients and i - takes the integer values 0, 1, 2, 3), as well as synchronization pulses, the first output of the pulse generator is a signal, the second is the synchronization output, the common bus of the pulse generator is grounded; a four-arm bridge electric circuit consisting of two parallel-connected branches, the first of which includes two terminals for connecting two-terminal measuring objects and a single resistor of the first shoulder of the ratio, the first terminal is connected to the first output of the pulse generator, the common output of the second terminal and a single resistor forms the first output terminal of the bridge circuit, the free terminal of a single resistor is grounded, the second branch of the bridge circuit includes one connected in series full-time resistor of the second arm of the relationship and a multi-element bipolar, the free output of a single resistor is connected to the first output of the pulse generator, the common output of a single resistor and a multi-element bipolar forms a second output of the bridge circuit, the free output of a multi-element bipolar is grounded, a multi-element bipolar consists of a series-connected first resistor and inductance, a second resistor and capacitor, the free terminal of the first resistor is connected to the second terminal in stroke bridge circuit, free output inductor grounded one of the terminals of the second resistor is grounded, one of the terminals of the capacitor is connected to the common terminal of the first resistor and the inductor; a null indicator, to the first input of which (differential input) both outputs of the bridge circuit output are connected, to the second input (synchronization input) of the null indicator, the second output (synchronization output) of the pulse generator is connected, the common bus of the null indicator is grounded, three additional resistors are introduced , an additional capacitor, an additional inductor and the inclusion of elements is changed, the first additional resistor, an additional capacitor, a second additional resistor and an additional are connected in series the inductance coil, the free output of the first additional resistor is connected to the second output terminal of the bridge circuit, the free output of the additional inductor is grounded, the third additional resistor is connected between the common output of the existing first resistor, the existing inductor and the existing capacitor and the common output of the first additional resistor and additional capacitor , a free (non-grounded) terminal of an existing second resistor is connected to a common terminal of an existing first resistor and having an inductance coil having a capacitor and an additional third resistor, and the free available output capacitor is grounded.

The invention is illustrated in the drawing (Figure 1).

The bridge meter of the two-terminal parameters includes a pulse generator 1, which generates voltage pulses with voltage changes over their duration according to the law K ₀ t ⁰ , K ₁ t ¹ , K ₂ t ² , K ₃ t ³ , where K ₀ , K ₁ K ₂ , K ₃ - constant coefficients, t - time. These voltage pulses come from the signal output of the pulse generator 1 to the input of the bridge measuring circuit, which forms the common output of two parallel branches of the bridge circuit. Also, the pulse generator 1 generates synchronization pulses from the synchronization output of the pulse generator 1 to the synchronization input of the zero indicator 2. The common bus of the pulse generator 1 is grounded.

The first branch of the bridge circuit includes two terminals 3 and 4 connected in series for connecting two-terminal devices - objects of measurement and a single resistor of the first arm of ratio 5. Terminal 3 is connected to the signal output of pulse generator 1. The common output of resistor 5 and terminal 4 for connecting objects to measure the first output of the bridge circuit output. The free terminal of resistor 5 is grounded.

The second branch of the bridge circuit is formed in series by a single resistor of the second arm of relationship 6 and a multi-element bipolar. The free output of the resistor 6 is connected to the signal output of the pulse generator 1 and terminal 3 and forms the first output of the bridge circuit input.

A multi-element bipolar includes a circuit from a series-connected first resistor 7 and a first inductor 8. In parallel with this circuit, a circuit is connected from a series-connected first additional resistor 9, an additional capacitor 10, a second additional resistor 11 and an additional inductor 12. The total output of the resistors 6, 7 and 9 form the second output of the bridge circuit output. A resistor 13 is connected parallel to the inductor 8. A capacitor 14 is also connected parallel to the inductor 8. The first output of the resistor 15 is connected to the common output of the resistor 7, inductor 8, resistor 13 and capacitor 14. The second output of resistor 15 is connected to the common output of additional resistor 9 and additional capacitor 10. The total output of the inductor 8, the additional inductor 12, the resistor 13 and the capacitor 14 is grounded and together with the grounded output of the resistor 5 forms the second output terminal input th circuit.

To the first input of the zero indicator 2 (differential input), both outputs of the bridge circuit output are connected. The second input of the zero indicator 2 (synchronization input) is connected to the synchronization output of the pulse generator 1. The common bus of the zero indicator 2 is grounded.

As examples of two-terminal devices - objects of measurement - two-terminal networks R-C, R-L and R-L-C are given. An example of a resistive-capacitive RC double-pole contains a resistor 16, in parallel to which a circuit from a series-connected capacitor 17 and a resistor 18 is connected, a capacitor 19 is connected in parallel to a resistor 18. An example of a resistive-inductive two-terminal RL contains a series-connected resistor 20 and an inductor 21, parallel to the inductor 21 a resistor 22 and an inductor 23 are connected in series. Finally, an example of a two-terminal RLC includes a resistor 24, in parallel with which a circuit is connected and h series-connected capacitor 25, a resistor 26 and an inductor 27.

Exemplary elements of the bridge circuit 5 (R ₅ ), 6 (R ₆ ), 7 (R ₇ ), 9 (R ₉ ), 10 (C ₁₀ ), 11 (R ₁₁ ), 12 (L ₁₂ ) have known and constant values parameters, and the resistance values 7 (R ₇ ) and 9 (R ₉ ) are equal. Exemplary elements of the bridge circuit 8 (L ₈ ), 13 (R ₁₃ ), 14 (C ₁₄ ), 15 (R ₁₅ ) have known adjustable parameter values and are used to balance the bridge chain. Finally, elements 16 (R ₁₆ ), 17 (C17), 18 (R ₁₈ ), 19 (C ₁₉ ); 20 (R ₂₀ ), 21 (L ₂₁ ), 22 (R ₂₂ ), 23 (L ₂₃ ); 24 (R ₂₄ ), 25 (C ₂₅ ), 26 (R ₂₆ ), 27 (L ₂₇ ) have unknown parameter values and relate to two-terminal objects of measurement.

Before the start of the next pulse from the signal output of the pulse generator 1, the reactive elements of the bridge circuit are free of energy reserves, and the voltage at the input and output of the bridge circuit is zero. At each stage of balancing under the influence of the next pulse in the bridge circuit at the beginning of the pulse and after its end, transients occur in the form of voltage spikes at the output of the bridge circuit, which decay to zero during the transition process. The part of the pulse from the output of the bridge circuit from the end of the transition process to the end of the pulse is useful, it has a flat top.

Consider the operation of a bridge meter when connecting to the bridge circuit of a two-terminal RC measurement object containing elements 18 (R ₁₈ ), 19 (C ₁₉ ), 20 (R ₂₀ ) and 21 (C ₂₁ ). First, rectangular pulses K ₀ t ⁰ are supplied to the bridge circuit from the pulse generator 1. By adjusting the resistance value of resistor 15 (R ₁₅ ), we bring the flat peak of the pulse voltage from the bridge output (nonequilibrium voltage) to zero, noting this hereafter in terms of zero indicator 2, for which, for example, an oscilloscope can be used. As a result (with R ₇ = R ₉ ), the first equilibrium condition is satisfied

$${\text{A}}_{\text{one}}={\text{R}}_{\text{7}}{\text{R}}_{\text{16}}{\text{(R}}_{\text{fifteen}}+{\text{R}}_{\text{7}}{\text{) -R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{(R}}_{\text{fifteen}}+{\text{2R}}_{\text{7}}\text{)}=\text{0}\text{. (one)}$$

The count of the unknown resistance value 16 (R ₁₆ ) of the studied two-terminal network is taken from the equilibrium condition (1), where the parameter values of all other elements (R ₅ , R ₆ , R ₇ = R9, R ₁₅ ) are known. Hereinafter, synchronization pulses from the pulse generator 1 ensure the stability of the readings of the zero indicator 2.

After that, a linearly varying voltage pulse (K ₁ t ¹ ) is supplied to the bridge circuit from a pulse generator ¹ . By adjusting the value of the inductance of coil 8 (L ₈ ), the flat peak of the nonequilibrium voltage pulse is reduced to zero, and thus the second equilibrium condition is satisfied

$${\text{A}}_{\text{2}}={\text{R}}_{\text{16}}{\text{[L}}_{\text{8}}{\text{(R}}_{\text{fifteen}}+{\text{2R}}_{\text{7}}\text{)}+{\text{R}}_{\text{fifteen}}{\text{(C}}_{\text{10}}{\text{R}}_{\text{7}}^{\text{2}}{\text{-C}}_{\text{fourteen}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{) -2R}}_{\text{7}}{\text{C}}_{\text{fourteen}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{] -2C}}_{\text{10}}{\text{R}}_{\text{fifteen}}{\text{R}}_{\text{7}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}=\text{0}\text{.}\text{(2)}$$

In this case, the resistance value of the resistor 15 (R ₁₅ ) should not be adjusted, since this will lead to a violation of the first equilibrium condition (1), which is unacceptable. The count of the unknown parameter C ₁₇ is taken from expression (2), since the remaining values in it are known, including the resistance value 16 (R ₁₆ ) from expression (1).

Then, quadratic pulses (K ₂ t ² ) are applied to the bridge circuit from the pulse generator 1. By adjusting the resistance value of the resistor 13 (R ₁₃ ), the flat peak of the nonequilibrium voltage pulse is reduced to zero and the third equilibrium condition is satisfied:

Параметры элементов 15 (R₁₅) и 8 (L₈) при этом регулировать нельзя, так как это приведет к нарушению выполнения первых двух условий равновесия (1) и (2). Отсчет неизвестного параметра R₁₈ берется из (3), так как остальные величины в нем известны, в том числе R₁₆ из (1) и С₁₇ из (2). $$\begin{array}{l}{\text{A}}_{\text{3}}={\text{[[[{[R}}_{\text{7}}{\text{C}}_{\text{17}}{\text{(R}}_{\text{7}}{\text{R}}_{\text{eighteen}}{\text{-2R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{) -R}}_{\text{eleven}}{\text{(C}}_{\text{17}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{-L}}_{\text{8}}{\text{)] R}}_{\text{13}}+{\text{L}}_{\text{8}}{\text{R}}_{\text{7}}^{\text{2}}{\text{} R}}_{\text{fifteen}}\text{-}\\ {\text{-2R}}_{\text{13}}{\text{R}}_{\text{eleven}}{\text{R}}_{\text{7}}{\text{(C}}_{\text{17}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{-L}}_{\text{8}}{\text{)] C}}_{\text{10}}+{\text{L}}_{\text{8}}{\text{C}}_{\text{17}}{\text{(R}}_{\text{13}}{\text{R}}_{\text{eighteen}}{\text{-R}}_{\text{6}}{\text{R}}_{\text{5}}{\text{) (R}}_{\text{fifteen}}+{\text{2R}}_{\text{7}}{\text{)]] R}}_{\text{16}}\text{-}\\ {\text{-2C}}_{\text{10}}{\text{R}}_{\text{fifteen}}{\text{R}}_{\text{7}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{(L}}_{\text{8}}+{\text{R}}_{\text{13}}\text{C}{}_{\text{17}}\text{R}{}_{\text{eighteen}}\text{)}=\text{0}\text{. (3)}\end{array}$$

The parameters of the elements 15 (R ₁₅ ) and 8 (L ₈ ) cannot be adjusted in this case, since this will lead to a violation of the fulfillment of the first two equilibrium conditions (1) and (2). The count of the unknown parameter R ₁₈ is taken from (3), since the other quantities in it are known, including R ₁₆ from (1) and C ₁₇ from (2).

Then, cubic pulses (K ₃ t ³ ) are supplied to the bridge circuit from the pulse generator 1. By adjusting the value of the resistance of the capacitor 14 (C ₁₄ ), the flat peak of the nonequilibrium voltage pulse is reduced to zero and the fourth equilibrium condition is satisfied:

$$\begin{array}{l}{\text{A}}_{\text{four}}={\text{L}}_{\text{8}}{\text{[[R}}_{\text{16}}{\text{[[C}}_{\text{10}}{\text{[R}}_{\text{one}}{}_{\text{5}}{\text{{R}}_{\text{7}}{\text{[2C}}_{\text{17}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{-R}}_{\text{7}}{\text{R}}_{\text{eighteen}}{\text{(C}}_{\text{17}}+{\text{C}}_{\text{19}}\text{)]}+{\text{R}}_{\text{eleven}}{\text{C}}_{\text{17}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}\text{}}+\\ +{\text{2R}}_{\text{eleven}}{\text{R}}_{\text{7}}{\text{C}}_{\text{17}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{-R}}_{\text{13}}{\text{{L}}_{\text{12}}{\text{(R}}_{\text{fifteen}}+{\text{2R}}_{\text{7}}\text{)}+{\text{R}}_{\text{fifteen}}{\text{[C}}_{\text{fourteen}}{\text{R}}_{\text{7}}^{\text{2}}+{\text{R}}_{\text{eleven}}{\text{R}}_{\text{eighteen}}{\text{(C}}_{\text{17}}+{\text{C}}_{\text{19}}{\text{) -C}}_{\text{17}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}\text{]}+\\ +{\text{2R}}_{\text{7}}{\text{[R}}_{\text{eleven}}{\text{R}}_{\text{eighteen}}{\text{(C}}_{\text{17}}+{\text{C}}_{\text{19}}{\text{) -C}}_{\text{17}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}\text{]}]}+{\text{C}}_{\text{17}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{(R}}_{\text{fifteen}}+{\text{2R}}_{\text{7}}{\text{) (C}}_{\text{19}}{\text{R}}_{\text{eighteen}}+{\text{C}}_{\text{fourteen}}{\text{R}}_{\text{13}}\text{)]]}+\\ +{\text{2C}}_{\text{10}}{\text{R}}_{\text{fifteen}}{\text{R}}_{\text{7}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{[C}}_{\text{fourteen}}{\text{R}}_{\text{13}}+{\text{R}}_{\text{eighteen}}{\text{(C}}_{\text{17}}+{\text{C}}_{\text{19}})]]]+{\text{C}}_{\text{10}}{\text{R}}_{\text{13}}{\text{C}}_{\text{17}}{\text{R}}_{\text{5}}{\text{R}}_{\text{16}}{\text{R}}_{\text{6}}{\text{{L}}_{\text{12}}{\text{(R}}_{\text{fifteen}}+{\text{2R}}_{\text{7}}\text{)}+\\ {\text{C}}_{\text{19}}{\text{R}}_{\text{eighteen}}{\text{[R}}_{\text{fifteen}}{\text{(R}}_{\mathrm{eleven}}+{\text{2R}}_{\text{7}}\text{)}+{\text{2R}}_{\text{eleven}}{\text{R}}_{\text{7}}\text{]}}=\text{0}\text{. (four)}\end{array}$$

The parameters of the elements 15 (R ₁₅ ), 8 (L ₈ ) and 13 (R ₁₃ ) cannot be adjusted, since this will lead to a violation of the fulfillment of the first three equilibrium conditions (1), (2) and (3). The count of the unknown parameter R ₁₈ is taken from (4), since the remaining values in it are known, including R ₁₆ from (1), C ₁₇ from (2) and R ₁₈ from (3).

When connecting a resistive-inductive (RL) two-terminal circuit to the bridge circuit of the measurement object containing the elements 20 (R ₂₀ ), 21 (L ₂₁ ), 22 (R ₂₂ ), 23 (L ₂₃ ), the above balancing steps are used in the previous sequence. The same forms of supplying pulsed signals, the same adjustable parameters and the previous sequence of regulation of their values are saved: R ₁₅ , L ₈ , R ₁₃ , C ₁₄ . Equilibrium conditions for four stages are given:

$${\text{A}}_{\text{one}}={\text{R}}_{\text{7}}{\text{R}}_{\text{twenty}}{\text{(R}}_{\text{fifteen}}+{\text{R}}_{\text{7}}{\text{) -R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{(R}}_{\text{fifteen}}+{\text{2R}}_{\text{7}}\text{)}=\text{0, (5)}$$

$$\begin{array}{l}{\text{A}}_{\text{2}}={\text{{(L}}_{\text{21}}+{\text{C}}_{\text{10}}{\text{R}}_{\text{fifteen}}{\text{R}}_{\text{twenty}}{\text{) R}}_{\text{7}}+{\text{[(L}}_{\text{21}}{\text{-2R}}_{\text{6}}{\text{R}}_{\text{5}}{\text{C}}_{\text{10}}{\text{) R}}_{\text{fifteen}}+{\text{2L}}_{\text{8}}{\text{R}}_{\text{twenty}}{\text{]} R}}_{\text{7}}+\\ +{\text{L}}_{\text{8}}{\text{R}}_{\text{fifteen}}{\text{R}}_{\text{twenty}}=\text{0, (6)}\end{array}$$

$$\begin{array}{l}{\text{A}}_{\text{3}}={\text{L}}_{\text{21}}{\text{[L}}_{\text{8}}{\text{{R}}_{\text{22}}{\text{[R}}_{\text{7}}{\text{(R}}_{\text{7}}+{\text{R}}_{\text{fifteen}}+{\text{2R}}_{\text{13}}\text{)}+{\text{R}}_{\text{fifteen}}{\text{R}}_{\text{13}}\text{]}+{\text{R}}_{\text{13}}{\text{R}}_{\text{twenty}}{\text{(R}}_{\text{fifteen}}+{\text{2R}}_{\text{7}}\text{)}}+\\ +{\text{C}}_{\text{10}}{\text{R}}_{\text{l3}}{\text{R}}_{\text{7}}{\text{{R}}_{\text{7}}{\text{[R}}_{\text{l5}}{\text{(R}}_{\text{twenty}}+{\text{R}}_{\text{22}}\text{)}+{\text{R}}_{\text{eleven}}{\text{R}}_{\text{22}}\text{]}+{\text{R}}_{\text{l5}}{\text{(R}}_{\text{eleven}}{\text{R}}_{\text{22}}{\text{-2R}}_{\text{5}}{\text{R}}_{\text{6}}\text{)}]}+\\ +{\text{C}}_{\text{10}}{\text{R}}_{\text{l3}}{\text{R}}_{\text{7}}{\text{{R}}_{\text{7}}{\text{[R}}_{\text{l5}}{\text{(R}}_{\text{twenty}}+{\text{R}}_{\text{22}}\text{)}+{\text{R}}_{\text{eleven}}{\text{R}}_{\text{22}}\text{]}+{\text{R}}_{\text{l5}}{\text{(R}}_{\text{eleven}}{\text{R}}_{\text{22}}{\text{-2R}}_{\text{5}}{\text{R}}_{\text{6}}\text{)}]}+\\ +{\text{C}}_{\text{10}}{\text{L}}_{\text{8}}{\text{R}}_{\text{22}}{\text{{R}}_{\text{twenty}}{\text{[R}}_{\text{fifteen}}{\text{(R}}_{\text{7}}^{\text{2}}+{\text{R}}_{\text{13}}{\text{R}}_{\text{eleven}}\text{)}+{\text{2R}}_{\text{13}}{\text{R}}_{\text{eleven}}{\text{R}}_{\text{7}}{\text{] -2R}}_{\text{fifteen}}{\text{R}}_{\text{7}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}\text{}}=\text{0, (7)}\end{array}$$

$$\begin{array}{l}{\text{A}}_{\text{four}}={\text{L}}_{\text{8}}{\text{[[L}}_{\text{21}}{\text{[[L}}_{\text{23}}{\text{[R7 (R}}_{\text{7}}+{\text{R}}_{\text{fifteen}}+{\text{2R}}_{\text{13}}\text{)}+{\text{R}}_{\text{fifteen}}{\text{R}}_{\text{13}}\text{]}+{\text{R}}_{\text{7}}{\text{[R}}_{\text{7}}{\text{{R}}_{\text{22}}{\text{[R}}_{\text{13}}{\text{(C}}_{\text{fourteen}}+{\text{C}}_{\text{10}}\text{)}+{\text{C}}_{\text{10}}\\ {\text{(R}}_{\text{fifteen}}+{\text{R}}_{\text{eleven}}\text{)]}+{\text{C}}_{\text{10}}{\text{R}}_{\text{fifteen}}{\text{R}}_{\text{twenty}}\text{}}++{\text{R}}_{\text{22}}{\text{{R}}_{\text{fifteen}}{\text{[R}}_{\text{13}}{\text{(C}}_{\text{fourteen}}+{\text{C}}_{\text{10}}\text{)}+{\text{C}}_{\text{10}}{\text{R}}_{\text{eleven}}\text{]}+{\text{2C}}_{\text{10}}{\text{R}}_{\text{13}}{\text{R}}_{\text{eleven}}\text{}}+\\ +{\text{2C}}_{\text{10}}{\text{(R}}_{\text{l 3}}{\text{R}}_{\text{eleven}}{\text{R}}_{\text{twenty}}{\text{-R}}_{\text{fifteen}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}\text{)]}+{\text{C}}_{\text{10}}{\text{R}}_{\text{l 5}}{\text{R}}_{\text{13}}{\text{R}}_{\text{eleven}}{\text{(R}}_{\text{twenty}}+{\text{R}}_{\text{22}}\text{)]] -}\\ {\text{C}}_{\text{10}}{\text{[2R}}_{\text{fifteen}}{\text{R}}_{\text{7}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{(L}}_{\text{23}}+{\text{C}}_{\text{l4}}{\text{R}}_{\text{l3}}{\text{R}}_{\text{22}}{\text{) -R}}_{\text{twenty}}{\text{{R}}_{\text{l5}}{\text{[L}}_{\text{23}}{\text{(R}}_{\text{7}}^{\text{2}}+{\text{R}}_{\text{13}}{\text{R}}_{\text{eleven}}\text{)}+{\text{R}}_{\text{l3}}{\text{R}}_{\text{22}}{\text{(L}}_{\text{12}}+{\text{C}}_{\text{fourteen}}{\text{R}}_{\text{7}}^{\text{2}}\text{)]}+\\ +{\text{2R}}_{\text{13}}{\text{R}}_{\text{7}}{\text{(L}}_{\text{12}}{\text{R}}_{\text{22}}+{\text{R}}_{\text{eleven}}{\text{L}}_{\text{23}}\text{)}]]}+{\text{C}}_{\text{10}}{\text{R}}_{\text{13}}{\text{R}}_{\text{7}}{\text{L}}_{\text{21}}{\text{{R}}_{\text{7}}{\text{[L}}_{\text{23}}{\text{(R}}_{\text{fifteen}}+{\text{R}}_{\text{eleven}}\text{)}+\\ +{\text{2R}}_{\text{13}}{\text{R}}_{\text{7}}{\text{(L}}_{\text{12}}{\text{R}}_{\text{22}}+{\text{R}}_{\text{eleven}}{\text{L}}_{\text{23}}\text{)}]]}+{\text{C}}_{\text{10}}{\text{R}}_{\text{13}}{\text{R}}_{\text{7}}{\text{L}}_{\text{21}}{\text{{R}}_{\text{7}}{\text{[L}}_{\text{23}}{\text{(R}}_{\text{fifteen}}+{\text{R}}_{\text{eleven}}\text{)}+\\ {\text{L}}_{\text{12}}{\text{R}}_{\text{22}}\text{]}+{\text{R}}_{\text{fifteen}}{\text{(L}}_{\text{12}}{\text{R}}_{\text{22}}+{\text{R}}_{\text{eleven}}{\text{L}}_{\text{23}}\text{)}}=\text{0}\text{. (8)}\end{array}$$

From them, the count of the values of the desired parameters is taken: R ₂₀ , L ₂₁ , R ₂₂ , L ₂₃ .

If a two-terminal RLC containing elements 24 (R ₂₄ ), 25 (C ₂₅ ), 26 (R ₂₆ ), 27 (L ₂₇ ) is connected to the bridge circuit, then the same forms of supply pulses are used, the same adjustable parameters and the same control sequence their meanings. Equilibrium conditions for four stages:

$${\text{A}}_{\text{one}}={\text{R}}_{\text{7}}{\text{R}}_{\text{24}}{\text{(R}}_{\text{fifteen}}+{\text{R}}_{\text{7}}{\text{) -R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{(R}}_{\text{fifteen}}+{\text{2R}}_{\text{7}}\text{)}=\text{0, (9)}$$

$$\begin{array}{l}{\text{A}}_{\text{2}}={\text{R}}_{\text{24}}{\text{{L}}_{\text{8}}{\text{(R}}_{\text{fifteen}}+{\text{2R}}_{\text{7}}\text{)}+{\text{R}}_{\text{7}}{\text{[R}}_{\text{7}}{\text{(C}}_{\text{10}}{\text{R}}_{\text{fifteen}}+{\text{C}}_{\text{25}}{\text{R}}_{\text{26}}\text{)}+{\text{C}}_{\text{25}}{\text{(R}}_{\text{fifteen}}{\text{R}}_{\text{26}}{\text{-2R}}_{\text{5}}{\text{R}}_{\text{6}}\text{)] -}\\ {\text{R}}_{\text{fifteen}}{\text{C}}_{\text{25}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{} -R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{[R}}_{\text{fifteen}}{\text{(2C}}_{\text{10}}{\text{R}}_{\text{7}}+{\text{C}}_{\text{25}}{\text{R}}_{\text{26}}\text{)}+{\text{2R}}_{\text{7}}{\text{C}}_{\text{25}}{\text{R}}_{\text{26}}\text{]}=\text{0, (10)}\end{array}$$

$$\begin{array}{l}{\text{A}}_{\text{3}}={\text{[[[{R}}_{\text{7}}{\text{[(L}}_{\text{8}}+{\text{R}}_{\text{13}}{\text{C}}_{\text{25}}{\text{R}}_{\text{26}}{\text{) R}}_{\text{7}}{\text{-2R}}_{\text{13}}{\text{C}}_{\text{25}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{] -R}}_{\text{13}}{\text{R}}_{\text{eleven}}{\text{(C}}_{\text{25}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{-L}}_{\text{8}}{\text{)} R}}_{\text{fifteen}}\text{-}\\ {\text{2R}}_{\text{13}}{\text{R}}_{\text{eleven}}{\text{R}}_{\text{7}}{\text{(C}}_{\text{25}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{-L}}_{\text{8}}{\text{)] C}}_{\text{10}}{\text{-C}}_{\text{25}}{\text{L}}_{\text{8}}{\text{(R}}_{\text{fifteen}}+{\text{2R}}_{\text{7}}{\text{) (R}}_{\text{6}}{\text{R}}_{\text{5}}{\text{-R}}_{\text{13}}{\text{R}}_{\text{26}}{\text{) lR}}_{\text{24}}\text{-}\\ {\text{-2C}}_{\text{10}}{\text{R}}_{\text{fifteen}}{\text{R}}_{\text{7}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{(L}}_{\text{8}}+{\text{R}}_{\text{13}}{\text{C}}_{\text{25}}{\text{R}}_{\text{26}}\text{)}=\text{0, (11)}\end{array}$$

$$\begin{array}{l}{\text{A}}_{\text{four}}={\text{R}}_{\text{24}}{\text{[[C}}_{\text{10}}{\text{L}}_{\text{8}}{\text{C}}_{\text{25}}{\text{{R}}_{\text{fifteen}}{\text{[R}}_{\text{7}}{\text{(2R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{-R}}_{\text{7}}{\text{R}}_{\text{26}}\text{)}+{\text{R}}_{\text{eleven}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}\text{]}+{\text{2R}}_{\text{eleven}}{\text{R}}_{\text{7}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}\text{} -}\\ {\text{-R}}_{\text{13}}{\text{]] [L}}_{\text{8}}{\text{[(R}}_{\text{fifteen}}+{\text{2R}}_{\text{7}}{\text{) [C}}_{\text{25}}{\text{(L}}_{\text{27}}{\text{-C}}_{\text{fourteen}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}\text{)}+{\text{C}}_{\text{10}}{\text{L}}_{\text{12}}\text{]}+\\ +{\text{C}}_{\text{10}}{\text{{R}}_{\text{fifteen}}{\text{[C}}_{\text{fourteen}}{\text{R}}_{\text{7}}^{\text{2}}+{\text{C}}_{\text{25}}{\text{(R}}_{\text{eleven}}{\text{R}}_{\text{26}}{\text{-R}}_{\text{5}}{\text{R}}_{\text{6}}\text{)]}+{\text{2R}}_{\text{7}}{\text{C}}_{\text{25}}{\text{(R}}_{\text{eleven}}{\text{R}}_{\text{26}}\text{-}\\ {\text{R}}_{\text{5}}{\text{R}}_{\text{6}})\}]=C_{10}{C}_{25}[R_{\mathrm{fifteen}})R_7^2{L}_{27}-L_{12}{R}_5{R}_6)-2L_{12}{R}_7{R}_5{R}_6]]]]]+\end{array}$$

$$+{\text{2C}}_{\text{10}}{\text{R}}_{\text{fifteen}}{\text{R}}_{\text{7}}{\text{R}}_{\text{5}}{\text{R}}_{\text{6}}{\text{[R}}_{{}_{\text{13}}}{\text{(C}}_{\text{fourteen}}{\text{L}}_{\text{8}}+{\text{C}}_{\text{25}}{\text{L}}_{\text{27}}\text{)}+{\text{L}}_{\text{8}}{\text{C}}_{\text{25}}{\text{R}}_{\text{26}}\text{]}=\text{0}\text{. (12)}$$

From them, the count of the values of the desired parameters R ₂₄ , C ₂₅ , R ₂₆ , L ₂₇ is taken.

After completing all four stages of balancing, the bridge is not brought to complete equilibrium, but four equilibrium conditions (four equations) are obtained, from which, as you know, we can take the count of the four desired parameters of the two-terminal objects of measurement. Such bridge circuits are quasi-balanced bridges.

Thus, the functionality of the given bridge meter of the two-terminal parameters is significantly expanded and it allows you to determine the parameters R-C, R-L and R-L-C of the two-terminal objects of measurement when connecting them to the same two terminals of the bridge circuit. At the same time, such an important quality of the bridge chain as separate balancing is preserved.

Claims (1)

A two-terminal bridge meter, containing a pulse generator that generates a pulse train of a rectangular, linearly varying, quadratic and cubic shape (u _i = K _i t ⁱ , where u _i is the voltage change in the pulse, K _i are constant coefficients and i takes integer values 0, 1,2, 3), as well as synchronization pulses, the first output of the pulse generator is a signal, the second is the synchronization output, the common bus of the pulse generator is grounded; a four-arm bridge electric circuit consisting of two parallel-connected branches, the first of which includes two terminals for connecting two-terminal measuring objects and a single resistor of the first shoulder of the ratio, the first terminal is connected to the first output of the pulse generator, the common output of the second terminal and a single resistor forms the first output terminal of the bridge circuit, the free terminal of a single resistor is grounded, the second branch of the bridge circuit includes one connected in series full-time resistor of the second arm of the relationship and a multi-element bipolar, the free output of a single resistor is connected to the first output of the pulse generator, the common output of a single resistor and a multi-element bipolar forms a second output of the bridge circuit, the free output of a multi-element bipolar is grounded, a multi-element bipolar consists of a series-connected first resistor and inductance, a second resistor and capacitor, the free terminal of the first resistor is connected to the second terminal in stroke bridge circuit, free output inductor grounded one of the terminals of the second resistor is grounded, one of the terminals of the capacitor is connected to the common terminal of the first resistor and the inductor; a null indicator, to the first input of which (differential input) both outputs of the bridge circuit output are connected, to the second input (synchronization input) of the null indicator, the second output (synchronization output) of the pulse generator is connected, the common bus of the null indicator is grounded, characterized in that three additional resistors, an additional capacitor, an additional inductor are introduced into it and the inclusion of elements is changed, the first additional resistor, an additional capacitor are connected in series, the second supplement a resistor and an additional inductor, the free output of the first additional resistor is connected to the second output terminal of the bridge circuit, the free output of the additional inductor is grounded, the third additional resistor is connected between the common terminal of the existing first resistor, the existing inductor and the existing capacitor and the common terminal of the first additional resistor and an additional capacitor, a free (non-grounded) terminal of an existing second resistor is connected to a common terminal an existing first resistor, an existing inductor, an existing capacitor and an additional third resistor, and the free terminal of the existing capacitor is grounded.