SU1651223A1 - Quasy-balanced converter of message-bearing parameter of pickup into frequency - Google Patents

Abstract

The invention relates to electrical measuring technology and can be used to convert sensor parameters with a dual-element non-resonant series iggy parallel replacement circuit. The aim of the invention is to improve the accuracy of the conversion due to the fact that the complex voltage component is compared with a given value, depending only on the informative parameter of the sensor. The device contains a generator 1, an amplifier 2, a sensor 3 (4), an exemplary element 4 (3), a rectifier 5, an in-phase 6 and a quadrature 7 phase-out rectifier and a comparison unit 8. 1 sludge. S

Description

Yu

O5

The invention relates to electrical measuring equipment, namely to measuring the parameters of two-element two-terminal networks, and can be used in the construction of transducers of sensor parameters represented by a two-element RL, RC series or parallel replacement circuit.

The aim of the invention is to improve the accuracy of the conversion of an informative parameter, by matching the converter with a reference voltage of a voltage that is proportional only to the informative parameter of the sensor, and not to the module of the impedance as in the display converter.

The drawing shows the functional diagram of the quasi-balanced converter of the informative parameter of the sensor into frequency.

The converter consists of the gene- 1, amplifier 2, sensor 3, sbraztsovogo element 4, rectifier 5, in-phase 6 and quadrature 7 phase-sensitive rectifiers, unit 8 of comparison. Elements 3 and 4 form a block 9 of the model and measured elements, which can be interchanged in block 9.

The Converter operates as follows.

The voltage from the output of generator 1 is applied to the input of amplifier 2, the output voltage of which is determined by the measured parameters of sensor 3 (4) and sample element 4 (3). In the case of a sequential two-element RgL sensor replacement circuit 3, the output voltage of amplifier 2

1 R

U2 u ivjfe)

where U is the generator output voltage;

RO - exemplary resistor; WITH - circular frequency

or

U, -U2

(R-x + -) (RO J -

This voltage is applied to the reference inputs of the phase-sensitive ends of the mi- blets 6 and 7, which separate the active ReU, respectively, and the reactive Imc U, the components of the voltage U1 with respect to the voltage and „:

The reactive component Im U. is fed to the input of the comparator unit 8, to the other input of which the rectified voltage is supplied from the output of the amplifier 2 U5 mud Ug. The voltage at the output of block 8

and&

where k

L th) bhch „

 (-) mud U "K.,

R0c

, - block transfer ratio

compare

changes the frequency of oscillator 1 before the onset of an equilibrium state characterized by the equality U ,. and (. In the equilibrium state, and the frequency of the generator is determined by

f - | 2

 About t

2 and Lx

The value of the non-informative parameter is determined by the output voltage of the in-phase, phase-sensitive rectifier 6:

-n 5 and to

When sensor 3 is represented by a sequential K Cx-replacement circuit, the transformation functions of its parameters are described by the expression

f -2Tc75 and R4 U2ti

If sensor 4 consists of a parallel connection RyLjj, then

0

five

f

Ro

and ReU2U H If

2 IT L j (uz lh

and for sensor 4 consisting of a parallel connection, the conversion functions are

f and Ren ui and - X Ro U2 2 R

In the case when the informative parameter of the sensor is resistance Ry, the reference element should be a capacitor and an inductor,

51

Thus, the converter allows you to convert the parameters of the sensors with a parallel circuit in the mode of a given current, and with a serial circuit in the mode of a given voltage.

Increased accuracy is achieved due to the fact that the complex voltage component is compared with a given value, depending only on the informative parameter of the sensor.

Claims (1)

Invention Formula A quasi / rabbed converter of an informative parameter of the sensor into a frequency, comprising a generator, the control input of which is connected to the output of the reference unit, the first input of which is connected to the output of pritetel,. the input of which is connected to the output of the amplifier, a block of exemplary and measurable elements} connected between the input and the output of the amplifier, characterized in that, in order to improve the accuracy of the conversion, the in-phase and quadrature phase-sensitive rectifiers are introduced, the signal inputs of which are connected to the output of the generator, and their reference inputs are connected to the output of the amplifier, the output of the quadrature phase-sensitive rectifier is connected to the second input of the comparator unit, and the output of the in-phase phase-sensitive rectifier is the output a quasi-equilibrated converter, while the generator output is connected to the second inputs of a block of model and measured elements.