RU2376608C1 - Bridge metre of parametres of two-terminal devices - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: invention refers to instrumentation equipment, automation and industrial electronics, namely it allows determining parametres of three-element two-terminal devices or parametres of sensors with three-element equivalent circuit. Bridge metre of parametres of two-terminal devices includes in-series connected generator of compound feeding electric signal, bridge circuit and null indicator. New feature of bridge metre of two-terminal devices parametres is introduction to two-terminal device with balancing elements, which is included in bridge circuit, of additional second capacitor which is parallel connected to available circuit from in-series connected first capacitor, first resistor and first inductivity, as well as additional second resistor which is parallel connected to available circuit from in-series connected first resistor and first inductivity; at that, three of five functional elements of two-terminal device with balancing elements are adjustable, and functional elements of two-terminal device of measuring object serve as unknown quantities of three parametres - first capacity, first resistor and first inductivity.

EFFECT: simplifying and speeding up measurement.

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Description

The invention relates to instrumentation, automation and pro-electronics. In particular, it allows you to determine the parameters of three-element bipolar or sensor parameters with a three-element equivalent circuit.

A known method of measuring complex complex resistances [1]. The meter circuit contains a generator supplying a complex electrical signal, namely a sinusoidal voltage and a DC voltage, a bridge circuit and a zero indicator.

Its disadvantage is multiple sequential adjustment of the values of the balancing parameters, which delays and complicates the measurement.

The closest in technical essence and the achieved result to the claimed device is the selected as a prototype method of balancing the bridge for measuring the parameters of the complex resistance [2]. The bridge meter contains a oscillating frequency generator, a bridge circuit for determining three parameters and a zero indicator.

The disadvantage of such a bridge meter is that to balance the bridge circuit, multiple adjustment of three parameters is required.

The problem to which the invention is directed, consists in simplifying and speeding up the measurement by providing the best option for balancing the bridge chain - separate balancing, i.e. one-time adjustment of the parameter values of each balancing element.

This is achieved by the fact that in a bridge meter of two-terminal parameters, it contains a generator of a supplying complex electric signal, forming a sequence of rectangular, linearly varying and quadratic pulses and having two outputs formed by three terminals, one of which is grounded, the first output relative to the ground is the output of the supply signals and connected to the generator diagonal of the four-arm bridge circuit, the second output relative to the ground is the synchronization output, in the first branch of the four-arm mo the bipolar circuit of the measurement object, consisting of a series-connected first resistor, a first inductance and a first capacitor, connected in series to a bipolar circuit with balancing elements, consisting of a series-connected first capacitor, a first resistor and a first inductance, in series on a second branch of a bridge circuit single resistors of the first shoulder of the relationship and the second shoulder of the relationship, respectively, the overall output of the two-terminal object This measurement and a single resistor of the first shoulder of the relationship forms the first output of the generator diagonal of the bridge circuit, the common output of the two-terminal with balancing elements and a single resistor of the second shoulder of the relationship is grounded and forms the second output of the generator diagonal of the bridge circuit, in the first branch of the bridge circuit the common output of the two-terminal object of measurement and two-terminal with balancing elements forms the first output of the measuring diagonal of the bridge circuit, in the second branch of the bridge circuit the general conclusion of a single res The ora of the first arm of the relationship and the single resistor of the second arm of the relationship forms the second output of the measuring diagonal of the bridge circuit, the first and second conclusions of the measuring diagonal form relative to the ground the differential output of the four-arm bridge circuit, which is connected to the differential input of the zero indicator, the common bus of which is grounded, and the second input zero indicator - the synchronization input is connected to the generator synchronization output, an additional second condensation is introduced into the two-terminal with balancing elements a torus that is connected in parallel with the existing circuit of the series-connected first capacitor, the first resistor and the first inductance, as well as an additional second resistor, which is connected in parallel with the existing circuit of the series-connected first resistor and the first inductance.

The invention is illustrated in the drawing. The two-terminal bridge meter contains a complex electric signal generator 1, which can generate sequences of rectangular, linearly varying and quadratic pulses and has two outputs formed by three terminals, one of which is grounded, the first output relative to the ground is the output of the supply signals and connected to the four-arm generator diagonal bridge circuit, the second output relative to ground is the synchronization output. In the first branch of the bridge circuit, the two-terminal of the measurement object is consistently connected, consisting of the first resistor 2 (R2), the first inductance 3 (L3), the first capacitor 4 (C4) connected in series, and the two-terminal with balancing elements, consisting of the first capacitor 5 connected in series C5), the first resistor 6 (R6) and the first inductance 7 (L7), as well as the second capacitance 11 (SP), which is connected in parallel with the existing circuit of the series-connected first capacitor 5 (C5), the first resistor 6 (R6), the first inductance 7 (L7), and the second resistor 12 (R12), connected in parallel to the existing circuit from the series-connected first resistor 6 (R6) and the first inductance 7 (L7). In the second branch of the bridge circuit, a single resistor of the first arm of ratio 8 (R8) and a single resistor of the second arm of ratio 9 (R9) are connected in series. The common terminal of the two-terminal object of measurement and the single resistor of the first link arm forms the first output of the generator diagonal of the bridge circuit, the common terminal of the two-terminal with balancing elements and the single resistor of the second link arm is grounded and forms the second terminal of the generator diagonal of the bridge circuit. In the first branch of the bridge circuit, the common output of the first resistor 4 (R4) of the two-terminal object of measurement and the first capacitance 5 (C5) of the two-terminal with balancing elements forms the first output of the measuring diagonal of the bridge circuit. In the second branch of the bridge circuit, the common terminal of the single resistor of the first arm of ratio 8 (R8) and the single resistor of the second arm of ratio 9 (R9) forms the second terminal of the measuring diagonal. The first and second conclusions of the measuring diagonal form, relative to the ground, the differential output of the four-arm bridge circuit, which is connected to the differential input of the zero indicator 10, the common bus of which is grounded, and the second input of the zero indicator 10, the synchronization input, is connected to the synchronization output of the generator 1.

A bridge meter for the parameters of bipolar operates as follows. In the initial state, the voltages at the input and output of the four-arm bridge circuit are zero. We apply a rectangular pulse train to the bridge from generator 1. Under the influence of the next pulse in steady state, unchanging voltages are established in the branches of the bridge circuit, the difference of which determines the voltage in the measuring diagonal of the bridge circuit (output voltage of the bridge). It depends on the values of capacitances 4 (C4), 5 (C5), 11 (C11) and on the values of resistances 8 (R8) and 9 (R9). The first condition for equilibrium of the bridge

You can perform it by adjusting the capacitance of the capacitor 11 (C11). By a single adjustment of the capacitance value of this capacitor, the flat peak of the pulse nonequilibrium signal is reduced to zero, thereby fulfilling the first equilibrium condition of the bridge (1). The equilibrium of the bridge here and hereinafter is indicated by the zero indicator 10 (oscilloscope), while the supply of the synchronization signal from the second output of the generator 1 to the second input of the zero indicator 10 ensures the stability of its readings. Next, we feed to the bridge from the generator 1 a pulse train of a linearly varying voltage. When the next such pulse is applied, at the bridge output, after the end of the transient process, a pulse nonequilibrium signal with a flat top is established. Its voltage does not depend on the values of inductors 3 (L3) and 7 (L7). The second condition for the equilibrium of the bridge

By a single adjustment of the resistance value of the resistor 12 (R12), we bring the flat top of the impulse voltage of disequilibrium to zero, i.e. we fulfill the second equilibrium condition (2), while the first condition (1) is not violated, because the parameter 12 (R12) regulated here is not included in it. After that, we feed a sequence of quadratic pulses to the bridge from generator 1. Under the influence of the next pulse, after the end of the transition process, a pulse signal of disequilibrium with a flat top is established at the output of the bridge. The third condition for equilibrium of the bridge

By adjusting the inductance 7 (L7) once, we bring the flat peak of the impulse voltage of the disequilibrium to zero and fulfill the third equilibrium condition (3), while the first two equilibrium conditions (1), (2) are not violated, because the parameter 7 (L7) regulated here is not included in them.

From the above it follows that the bridge circuit (Figure 1) has the property of separate dependent dependent balancing, and balancing should be carried out in the above sequence 11 (C11), 12 (R12), 7 (L7). Of the three equations [three equilibrium conditions (1) - (3)], the count of the desired three parameters is taken: 4 (C4), 2 (R2), 3 (L3)

C ₄ = R ₉ (C ₁₁ + C ₅ ) / R ₈ ;

R ₂ = R ₆ R ₁₂ C ₅ (C ₄ R ₈ -R ₉ C ₁₁ ) / C ₄ R ₉ (C ₁₁ + C ₅ ) (R ₁₂ + R ₆ );

L ₃ = {L ₇ C ₅ R ₁₂ (C ₄ R ₈ -R ₉ C ₁₁ ) + C ₄ R ₂ R ₉ [(L ₇ (C ₁₁ + C ₅ ) + C ₁₁ C ₅ R ₆ R ₁₂ )] } / C ₄ R ₉ (R ₆ + R ₁₂ ) (C ₁₁ + C ₅ ).

Moreover, the values of the parameters of the elements 5 (C5), 6 (R6), 8 (R8), 9 (R9) are constant. All adjustable balancing elements - 11 (C11), 12 (R12), 7 (L7) are grounded.

Thus, this bridge meter of the two-terminal parameters allows for the individual balancing of the bridge circuit when performing single adjustments of the values of the balancing parameters, which simplifies and accelerates the measurement.

Information sources

1. A.S. 200662 USSR, IPC G01R 17/10. A method of measuring complex complex resistances. - Publ. 08/15/1967. Bull. No. 17.

2. A.S. 413430 USSR, M.C. G01R 17/10. A method of balancing a bridge to measure complex resistance parameters. - Publ. 01/30/1974. Bull. No. 4 (prototype).

Claims (1)

A bipolar parameter meter containing a generator of a supplying complex electrical signal that generates a sequence of rectangular, linearly varying and quadratic pulses, which has two outputs formed by three terminals, one of which is grounded, the first terminal relative to the ground is the output of the supply signals and connected to the four-arm generator diagonal bridge circuit, the second terminal relative to the ground is the synchronization output, in the first branch of the four-arm bridge chain a two-terminal device of the measurement object, consisting of a series-connected first resistor, a first inductance and a first capacitor, and a two-terminal network with balancing elements, a series-connected first capacitor, a first resistor and a first inductance, are connected in series to a single resistor of the first arm of the ratio and a single resistor of the second shoulder of the relationship, the total output of the two-terminal object of measurement and a single resistor of the first shoulder rel The system forms the first output of the generator diagonal of the bridge circuit, the general output of the two-terminal with balancing elements and a single resistor of the second shoulder of the relationship is grounded and forms the second output of the generator diagonal of the bridge circuit, in the first branch of the bridge circuit the general output of the two-terminal of the measurement object and the two-terminal with balancing elements forms the first output of the measuring the diagonal of the bridge circuit, in the second branch of the bridge circuit, the common output of a single resistor of the first arm of the relationship and a single resistor in The second shoulder of the measuring circuit diagonal of the bridge circuit forms the first shoulder, the first and second conclusions of the measuring diagonal form relative to the ground the differential output of the four-arm bridge circuit, which is connected to the differential input of the null indicator, the common bus of which is grounded, and the second input of the null indicator, the synchronization input, is connected with the synchronization output of the generator, characterized in that an additional second capacitor is connected to it in a two-terminal device with balancing elements, which is connected by steam llelno with existing chain of serially connected first capacitor, the first resistor and the first inductance and an additional second resistor which is connected in parallel with the existing chain of serially connected first resistor and the first inductor.

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