SU1027643A1 - Converter of pickup resistance or capacity of time interval - Google Patents

Abstract

CONVERTER OF RESISTANCE OR CAPACITY OF THE SENSOR TO THE TEMPORARY INTERVAL, containing two integrators and a cmparator, the output of which is connected to one jxa of inputs, distinguished by the fact that, in order to linearize the conversion characteristics, increase speed and expand functionality, increase the speed and enhance the functionality, increase the speed and extend the functionality, increase the speed and expand the functionality, increase the speed and extend the functionality, increase the performance and enhance the functionality, increase the speed and expand the functionality, increase the speed and extend the functionality and the amplifier-limiter, and the output of the adder is connected to the inputs of the first and second integrators, the outputs of which are connected to the corresponding inputs of the second adder, the output which is connected to another input of the comparator, the output of the latter through the mussel limiter is connected to the code of the first adder and through the differential circuit with the output of the first generator.

Description

The invention relates to a measuring technique and can be applied in information-measuring systems using measuring sensors. A resistance to voltage converter is known that contains a first adder, one of the inputs of which is supplied with a reference voltage, and a second input connected to the output of a parametric element whose input is connected to the output of the first adder and one of the inputs of the second adder, the second input. the second adder is connected to the output of the parametric element flj. The disadvantage of the impedance-to-voltage converter with the nonlinear characterization of the sensor is its low .. functionality, which mainly consists in the fact that the automatic processing of measurement results requires their conversion, which leads to additional errors and instrumentation. costs. In addition, the transformation characteristic is sensitive to the effects of involuntary physical factors. The closest in technical essence to the proposed. is a ratiometric transducer of the output value of a parametric sensor in the period of electrical oscillations, containing a comparison unit connected to the integrator input, the output of which is connected to the zero-body input, the integrator output and the zero-body output are connected to the integrator input through the sensor, the output of which is connected to the input of the comparator unit 2J. The disadvantage of the ratiometric transducer of the output value of the parametric sensor during the period of electrical oscillations is the measurement error, which develops the discrepancy between the output value of the converter and the measured physical factor affecting the parametric sensor. In addition, this converter is characterized by low speed and can be used without circuit changes only for capacitive sensors. The purpose of the invention is to linearize the characteristics of the conversion, increase the speed and enhance the functional capabilities of the converter. The goal is achieved by the fact that two adders, a differentiator and a limiting amplifier, and an adder output connected to the inputs of the first and second integrators, are inserted into the transducer impedance of the sensor capacitance in the time interval containing two integrators and a comparator whose output is connected to one of the inputs. the outputs of which are connected to the corresponding inputs of the second adder, the output of which is connected to another input of the comparator, the output of the latter through the limiting amplifier is connected to the input of the first th adder and through differenshfukltsuyu circuit with output of the first intetratora. The drawing shows the functional electrical circuit of the converter. The converter contains adder 1, differentiator 2, the first integrator 3 with one parametric sensor in the feedback circuit with elements R and C, the second integrator 4 with another parametric sensor in the feedback circuit, the second adder 5, comparator 6, amplifier 7 The first input of the adder I is connected to the output of the amplifier-limiter 7, the second input to the output of the integrator 3 via differentiator 2 (C). The output of the adder L is connected to the inputs of the integrators 3 and 4. The outputs of the integrator 3 and 4 are connected to the inputs of the adder 5, the output of the adder 5 is connected to the input of the comparator 6, the output of which is connected to the input of the amplifier limiter 7, During the operation of the converter, the polarized voltages the outputs of the amplifier-limiter 7 are fed directly to one of the inputs of the adder I. The comparator 6 is held naked and is triggered when the voltage at the output of the adder 5 is equal to the threshold. This changes the sign of the output voltage of the comparator 6 and, accordingly, the sign of the steepness of the variable voltage at the output of the adder 5. The actual conversion characteristics of the parametric sensors included in the feedback circuit of integrators 3 and 4, due to a number of reasons, differ Therefore, it is necessary to correct them. In the case of severities, the characteristic transform {| and with sufficient accuracy can be approximated by looking like: about 14 / 5X

- cf f - constant coefficient; Rjj and C are the parameters of a resistive or capacitive sensor at X 0 included in the feedback circuit of integrators 3 and 4; . X is the value of a measured physical quantity. When the constant time of intrato3 is defined as

(four

Hfg o ffpK

where T |, ROS

sc

 - the time constant of the integrator 3 with zero exposure to the physical quantity X No. & sensor.

The voltage at the output of the adder 4 is extended through the voltage U .. We obtain

and

V --- 5-, 5 PV

where t-, pt.

Assume that during the integration time physical impact (x "const) | then

and.

V 11 -ii 3 Z-op X

meas

-duration of integ. during which “the reduction at the output of the adder 5 aostigai the reference voltage of the comparator 6.

Marking the value

will get

X VT

Mem

Thus, the device of the device implements a linear, pre-phased, and human variable

Moreover, the transducer functionality is increased, since it can be used for resistive and capacitive sensors with simultaneous formation of an informative parameter of the sensor in a convenient form for further processing. The use of the auto-tact integration allows the cymecTB fflo to reduce the influence of destabilizing factors.

Claims (1)

TRANSFER OF RESISTANCE OR SENSOR CAPACITY IN THE TIME INTERVAL, containing two integrators and a comparator, the output of which is connected to one of the inputs, characterized in that, in order to linearize the conversion characteristics, increase speed and expand the functionality, two adders are introduced into it, a differentiating circuit and an amplifier-limiter, and the output of the first adder is connected to the inputs of the first and second integrators, the outputs of which are connected to the corresponding inputs of the second adder, the output which is connected to another input of the comparator, the output of the last human. cut amplifier limiter connected to the input of the first adder and through diffe; rotating circuit with the output of the first integrator. <0 £