SU1516750A1 - Converter of displacement to pulse duration - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure displacements. In order to improve accuracy by eliminating the error caused by the influence of the communication line parameters in the converter containing resistive element 1, fixed electrode 2, movable electrode 3, resistive element 4, interference suppression unit 5, integrator 6, threshold unit 7, bus 13 zero potential, a distributor of 8 pulses, a two-polar source 9 of the reference voltage, and switches 10-12 are introduced. The duration of the output pulses of the converter is proportional to the measured displacement and does not depend on the parameters of the communication line connecting the sensor to the reading part and the change in the transmission coefficient of the interference suppression unit 5. 2 Il.

Description

Phase.1

3151

The invention relates to a measurement technique and can be used to measure displacements.

The purpose of the invention is to improve the accuracy by eliminating the error caused by the influence of communication link parameters and.

Figure 1 presents the block diagram of the Converter; figure 2 - the timing diagram of his work.

The converter contains a resistive element 1, a fixed electrode 2, a movable electrode 3, a resistive element k, an interference suppression unit 5, an integrator 6, a threshold unit 7, a pulse distributor 8, a two-pole reference voltage source 9, switches 10-12, a bus 13 zero potential.

The stationary electrode 2 is connected to the noise suppression unit 5, the output of which is connected to the input of the integrator 6, the output of which is connected to the input of the threshold unit 7, one of the terminals of the resistive element 1 is connected by the bus 13, the outputs of the two polarity source 9 of the reference voltage through the switch 10 alternately connected to the second output of the resistive element 1, the first output of the resistive element C via the switch 11 is alternately connected to the first and second terminals, and the second through the switch 12 to the second and first terminals of the resistive element 1. The input of the distributor 8 pulses is connected to the output of the threshold unit 7 and the outputs to the control inputs of the switches 10-12 and the input of the source 9.

The Converter operates as follows.

In the time interval T, specified by the distributor 8 pulses, the signal + Uo is sent to the resistive element 1 through the switch 10 and to the resistive element through the switches 10 and 12. The second output of the resistive element at this time is connected to the bus 13 via the switch 11, i.e. resistive elements 1 and 4 are connected in parallel

Through the interference suppression unit 5, the integrator 6 receives a signal proportional to the measured relative movement S / S with a transmission coefficient determined by the parameters of the communication line K and the interference suppression unit 5 F:

and, K, cF - and ,.

. The voltage at the output of the integrator 6 is changed according to the following law:

and,

K c fUo- /,

five/

That if

-P where t is the constant of integrator time 6.

After the end of the time interval T, the resistive element 1 through the switch 10 and the resistive element through the switches 10 and 11 is given a signal-Up. The first output of the resistive element at this time is connected to the bus 13, i.e. resistive elements 1 and C are connected in series. In this case, the signal from the output of the interference suppression unit 5 does not depend on the measured displacement and is determined as follows:

Then, at the output of the integrator 6, the voltage is written as follows:

That s / o f

TI -k 17 - IT -2. V TG -C. -J U / -P .., G „and- XI iN-.r g- .g.

, S „TO V p Us

hp 2 o

when the voltage is equal to zero, the threshold unit 7 is triggered on the integrator 6, after which the entire described process is repeated.

The period of relaxation oscillations is determined from the condition that the voltage on the integrator 6 is zero:

T 2 | --TO + T t, + T ,.

Thus, the duration of the output pulses of the converter is proportional to the measured displacement and does not depend on the parameters of the communication line connecting the sensor to the converter and the change in the transmission coefficient of the interference suppression unit 5.

Claims (1)

Invention Formula A transducer to pulse duration, containing two resistive elements, a fixed electrode, a movable electrode, an interference suppression unit, an integrator, a threshold unit, a zero potential bus, the first and second resistive elements are made in the form of resistance and extended plates of the same length another with a gap in which there is a movable electrode, configured to displacement in a plane parallel to the planes of the resistive elements, the fixed electrode is made in the form of an extended plate with a length equal to the length of the resistive elements, is located in the plane of the first resistive element under the moving electrode and is connected to the input of the suppression unit 1516750 The first, second, and third outputs of which are connected to the control input of the first, second, and third switches, respectively, the fourth output of the pulse distributor is connected to the input of a two-pole reference voltage source, the midpoint of which is connected to the zero bus „- ..“. iiw rvjiiuMeHcj to bus zero interference, the output of which is through the integral, potential, and the first and second torus is connected to the first input of the threshold, respectively, connected to and the second inputs of the first switch, the output of which is connected to the second If ./ The first unit, the zero potential bus is connected to the second input of the threshold unit and the first output of the first resistive element, characterized in that, with the aim of increasing accuracy, a pulse distributor, a two-pole reference voltage source, 1 and three sets of the first resistive element J5 are inserted into it. and the measured inputs of the second and third switches, the outputs of which are connected respectively to the first and second terminals of the second resistive element, the second inputs of the second and r- -rr e - e --- r-yy :: EH Noah oo 1516750 The first, second, and third outputs of which are connected to the control input of the first, second, and third switches, respectively, the fourth output of the pulse distributor is connected to the input of a two-pole reference voltage source, the midpoint of which is connected to the zero bus .. ". iiw rvjiiuMeHcj to bus zero a-, potential, and the first and second o- are connected respectively to and the second inputs of the first switch, the output of which is connected to the second the output of the first resistive element J5 and the measured inputs of the second and third switches, the outputs of which are connected respectively to the first and second terminals of the second resistive element, the second inputs of the second and Up. fo sc P-h f o X 5. -. 2 Uo /. -. 2 2 g 0i / .2