SU1696846A1 - Displacement capacitive pickup - Google Patents

Abstract

This invention relates to a measurement technique. The purpose of the invention is to simplify the design and expand the measuring range of a capacitive displacement sensor. The sensor contains a current electrode, sections 1-4 of which are placed on one side of the surface of the dielectric plate 5 and connected through three to four groups. The potential electrode of the sensor consists of parallel-connected sections 6 located on another dielectric plate 7, which can move relative to the fixed plate 5 in the direction of changing the area of their mutual overlap. The groups of odd 1 and 3 and even 2 and 4 sections of the current electrode form, relative to sections 6 of the potential electrode, two differential capacitors connected, respectively, to the secondary converters 8 and 9 of their capacitance into electrical signals. The power generator 10 is connected to the sections of the potential electrode 7 and converters 8 and 9. At the output of these converters, direct voltage drivers 11 and 12 are connected, the outputs of which are connected to the input of unit 13 for determining the magnitude and direction of movement. 1 il. cl

Description

UNION OF SOVIET

SOCIALIST

REPUBLIC ·

, .., SU., N 1696846 A1 (51) 5 G 01 V 7/00

STATE COMMITTEE

BY INVENTIONS AND DISCOVERIES UNDER SCSTAN OF THE USSR

DESCRIPTION OF THE INVENTION

TO AUTHOR CERTIFICATE (21) 4729094/28 (22) 08/14/89 (46) 12/07/91. Bull. No. 45 (71) Moscow Mining Institute (72) V.A. Pavlenko (53) 621.317.39: 531.71 (088.8) (56) US Patent No. 3860018. cl. G 08 C 19/10, 340/200, 1980.

USSR copyright certificate No. 1252653, cl. G 01 B 7 / 00.1985.

(54) CAPACITIVE MOVEMENT SENSOR (57) The invention relates to measuring equipment. The purpose of the invention is to simplify the design and expand the measuring range of the capacitive displacement sensor. The sensor contains a current electrode, sections 1-4 of which are placed on one side of the surface of the dielectric plate 5 and connected through three to four groups. The potential sensor electrode consists of parallel-connected sections 6 located on another dielectric plate 7, which can move relative to the fixed plate 5 in the direction of changing the area of their mutual overlap. Groups of odd 1 and 3 and even 2 and 4 sections of the current electrode form two differential capacitors relative to sections 6 of the potential electrode, respectively connected to secondary converters 8 and 9 of their capacitance into electrical signals. The power generator 10 is connected to the sections of the potential electrode 7 and to the transducers 8 and 9. At the output of these converters are included rectangular shapers 11 and 12, the outputs of which are connected to the input of block 13 to determine the magnitude and direction of movement. 1 ill.

THX

1696846A1

The invention relates to measuring technique and can be used to measure movements,

The aim of the invention is to simplify the design and expand the measurement range 5 of the capacitive displacement sensor.

The drawing shows a block diagram of a capacitive displacement sensor.

! The sensor contains separated insets — 10 I potential and current electrodes, | installed with the possibility of relative movement in the direction of changing the area of their mutual overlap. The current electrode consists of several 15 identical sections, for example, 1,2, 3 and 4, etc., which are placed on one side of the dielectric plate 5. Sections 6 of the potential electrode are placed on the second dielectric plate 7, 20 mounted parallel to the first plate .

The sections of the current and potential electrodes are of the same size. The distance between the sections of the potential 25th electrode is equal to their width, and the distance between the sections of the current electrode is equal to half the width of the sections. The sections of the current electrode are interconnected through three sections to form four groups, 30 even and odd groups of which, for example, groups of sections 1-3 and 2-4, form two differential capacitors with parallel sections 6 of the potential electrode. The minimum number of sections of the current electrode ·· 35 is four, and the minimum number of sections of the potential electrode is three. The odd groups of sections 1 and 3 are connected to the inputs of the secondary converter 8. capacitance of one differential capacitor into an electrical signal. To the inputs of a similar secondary transducer 9 are connected even groups of sections 2 and 4 of the second differential capacitor of the capacitive sensor. The supply generator 10 is connected to parallel connected sections 6 of the potential electrode and to the supply inputs of the secondary converters 8 and 9, the outputs of which are connected to the rectifier 11 and 12. The outputs of the formers 11 and 12 of a rectangular voltage are connected to the inputs of the block 13 of the accumulating type, in which the magnitude and direction of movement are measured by the number and frequency of pulses arriving at it.

The sensor operates as follows.

When changing the overlap area of sections 1-4 of the current and sections 6 of the potential electrode, a counter-variation of the capacitance of both differential capacitors of the sensor occurs, which leads to the formation at the outputs of the secondary converters 8 and 9 of two signals phase-shifted by 90 degrees. These signals are converted using shapers 11 and 12 into rectangular voltage pulses supplied to the inputs of block 13, made in the form, for example, of a reversible pulse counter.

The capacitive sensor allows you to measure the magnitude and direction of movement in the range D equal to pF, where p is the number of sections of the current electrode; b is the width of its one section. Thus, choosing the width and number of sections, you can vary the measuring range over a fairly wide range.

Claims (1)

Claim Capacitive displacement sensor containing potential and current electrodes divided into sections, installed with the possibility of relative movement in the direction of changing the area of their mutual overlap, the width of the sections of the potential electrode is equal to the distance between them, as well as the width of the sections of the current electrode, characterized in that, in order to simplify construction and expansion of the measuring range, sections of the current electrode are placed one from another at a distance equal to half the width of one section, and are electrically connected between each other through three sections with the formation of four groups of sections, even and odd groups of sections of which form two differential capacitors with parallel sections of the potential electrode.