RU2562000C1 - Measuring device of voltage ratio of bridge sensors - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: measuring device of voltage ratio of bridge sensors includes working and comparative bridges, bridge power sources and a measuring amplifier. A negative feedback circuit of the measuring amplifier includes a comparative bridge that controls an amplification coefficient of an alternating-current amplifier connected with its output to the input winding of the transformer. Technical result is achieved by the fact that the device is also provided with working and comparative bridges. These bridges are connected in series with their measuring diagonals. The working bridges are provided with additional power sources, and the comparative bridges are connected with supply diagonals to additional output windings of the transformer. The formed tracking system of automatic control provides high accuracy of resultant measurements.

EFFECT: enlarging functional capabilities for measurement of the voltage ratio of bridge sensors.

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Description

The present invention relates to the field of measuring technology and can be used in processing information obtained during multivariate experimental studies.

Known devices for measuring the voltage ratio of bridge sensors in which electromechanical elements are used, including a rechord, a reversible electric motor and an electronic amplifier (ed. Certificate. USSR No. 180693, publ. March 26, 1966, Bull. No. 8).

A common disadvantage of these devices is their limited functionality, which makes it difficult to use in multifactor experimental studies.

The closest in technical essence to the present invention is a device adopted for the prototype, containing working and comparative bridges, bridge power supplies and a measuring amplifier, in the negative feedback circuit of which is included a comparative bridge that controls the gain of the AC amplifier (author certificate No. 180693 IPC G01R, CL 21e, 30/10, publ. March 26, 1966, Bull. No. 8).

The disadvantage of this device is its limited functionality, which complicates its use in multifactorial experimental studies.

The technical result of the claimed device is the expansion of functionality for measuring the voltage ratio of bridge sensors.

The technical result is achieved by the fact that the device for measuring the voltage ratio of bridge sensors, containing a working and comparative bridges, bridge power supplies and a measuring amplifier, the negative feedback circuit of which includes a comparative bridge that controls the gain of the AC amplifier connected to the input winding by its output transformer, is additionally equipped with working and comparative bridges, connected in series by measuring diagonals, while working You are provided with additional sources of supply, and comparative bridge diagonals power associated with the additional output windings of the transformer.

The figure 1 presents a block diagram of a device.

A device for measuring the voltage ratio of bridge sensors consists of an AC amplifier 1, working (measuring) bridges 2 ₁ ... 2 _n , stabilized power supplies 3 ₁ ... 3 _n , comparative bridges 4 ₁ ... 4 _n , transformer 5.

A device for measuring the voltage ratio of bridge sensors contains working bridges 2 ₁ ... 2 _n and comparative 4 ₁ ... 4 _n bridges connected to the input of the AC amplifier 1, the output of which is connected to the input winding of the transformer 5, in series with the supply diagonals 2 ₁ ... 2 _{n are} connected to stabilized power supplies 3 ₁ ... 3 _{n of} alternating current, and the diagonals of power of comparative bridges 4 ₁ ... 4 _{n are} connected to the output windings of transformer 5.

The purpose of the new circuit elements - additional working and comparative bridges - is clear from their name.

A device for measuring the voltage ratio of bridge sensors operates as follows.

The input of the amplifier 1, covered by negative feedback, is supplied from the working (measuring) bridges 2 ₁ ... 2 _n voltage:

,

,

where n = 1, 2, 3 ...;

- коэффициент передачи i-ого рабочего (измерительного) моста; $${\mathrm{TO}}_{mi}^{\text{'}\text{'}}$$

- gear ratio of the i-th working (measuring) bridge;

U _3i is the supply voltage of the i-th working (measuring) bridge.

The transmission coefficients of the comparative bridges 4 ₁ ... 4 _{n are} determined by the ratio:

.

.

, где k - коэффициент усиления усилителя с разомкнутой петлей обратной связи; β - отношение напряжения обратной связи к выходному напряжению усилителя:Since the gain of the feedback amplifier 1 is $$k_0=\frac{k}{\mathrm{one}+k\cdot \beta }$$

where k is the gain of the amplifier with an open feedback loop; β is the ratio of the feedback voltage to the output voltage of the amplifier:

.

.

For k · β >> 1

.

.

The voltage at the output of the amplifier in this case:

.

.

Thus, with a stabilized constant supply of U ₃ bridges 2 ₁ ... 2 _{n, the} output voltage of the amplifier is proportional to the ratio of the sum of the gear ratios of the measuring bridges to the sum of the gear ratios of the comparative bridges, which can be used in multivariate experimental studies.

The formed tracking automatic control system provides high accuracy of the resulting measurements while simultaneously measuring several controlled parameters.

Claims (1)

A device for measuring the voltage ratio of bridge sensors, containing the working and comparative bridges, bridge power supplies and a measuring amplifier, the negative feedback circuit of which includes a comparative bridge that controls the gain of the AC amplifier connected to the input winding of the transformer, characterized in that it is additionally equipped with working and comparative bridges, connected in series by measuring diagonals, while the working bridges are equipped with additional relative power sources, and comparative bridges with power diagonals are connected with additional output windings of the transformer.