SU1185069A1 - Capacitive movement transducer having a variable clearance - Google Patents

Abstract

CAPACITIVE CHANGE TRANSFORMER WITH A VARIABLE CLEAR containing two flat electrodes installed with an angular rotation capacity one relative to another around the axis of rotation, and a measuring circuit connected to them the transducer as a function of the angular displacement, the axis of rotation is made common to both electrodes and is located at the same constant distance From them, and its center is aligned with the line of intersection of the planes, which are the continuation of the active internal surfaces of the electrodes. (L SH) JV of Od CO

Description

The invention relates to measurement technology and can be used in various fields of science and technology for measuring angular movements, determining the stability of given angles in time, or their variations under the influence of external defects. The purpose of the invention is to improve the measurement accuracy of a capacitive displacement transducer with variable. gap by providing an unambiguous direct proportional dependence of capacitance trans. Razovatel. as a function of angular displacement. The drawing shows a schematic diagram of the proposed capacitive converter. The capacitive transducer contains two flat electrodes 1 and 2 mounted on supporting insulating plates 3 and 4 with the possibility of angular rotation one relative to the other around a common axis of rotation 5 located at the same constant distance from both electrodes 1 and 2. Center 6, the axis of rotation 5 is aligned with the line of intersection of the planes, which are a continuation of the active internal surfaces 7 and (electrodes 1 and 2. Outside, on the bearing plates 3 and 4 of the converter, screens 9 and 19 are connected, to the ground, and might The guard electrodes (not shown) connected to earth or an equipotential point are placed there.The measuring circuit, for example, a bridge circuit formed by the arms 11 and 12 of the transformer 13 s, is connected to the electrodes 1 and Z of the converter that form the capacitor Gd of variable capacitance constant (Pr) and adjustable (Pr) number of turns of the secondary winding and sample capacitor 14 with reference capacitance Wed To the primary winding of transformer 13 an AC power supply source 15 is connected, and an equilibrium detector 16 that serves as a bridge diagonal t for driving scheme equilibrate, carried emogo reg lirovkoy number of turns n-jf- transforms the torus 13. The converter operates as follows. As the angle d changes, between electrodes 1 and 2. The converter changes the capacitance C of the converter. According to the Gauss theorem, capacitive, resistance. the converter is equal to the wEbCn-dielectric constant of the medium between the electrodes 1 and 2 of the converter; b is the width of the transducer electrodes; gig - outer and inner / radii of the circles of rotation of the electrode transducer; and) is the circular frequency of the supply voltage. The equilibrium condition of the bridge measuring circuit is Xcft. P. So about where Xj.g- capacitance of the exemplary capacitor C ,,. According to (1) and (2), the measured angle d. rotation is determined by the ratio - - ". , P from which it follows that the measured angle Ы can be counted by the number of adjustable number of the number of turns of the secondary winding of the transformer 13, since all the values included in expression (3) are unchanged. Thus, between the measured angle o and the capacitive resistance X., it is ensured that the linear dependence is unambiguous in a given range of angular displacements. In this case, by using external screens 9 and 10, the influence of parasitic capacitances on the measurement results and guard electrodes is ensured to reduce the influence of edge effects. The advantage of the proposed converter is that it is able to accurately measure angles and angular displacements in the range of up to 50–60 °. This advantage is especially apparent when measuring small angular displacements (tenth, hundredth, fractions of a degree). In contrast to goniometers, where capacitive transducers with variable area are used, the proposed variable gap transducer in the measurement

311850694

small angles of its initial capacity can also significantly increase. With

The howl is chosen sufficiently large. This resolution transforms. In addition, the relative changes in the sweeper can range from 0.1

capacitance and, consequently. capacitance to 0.01 arc-second then

the resistance of the transducer s of known angular capacitance x

with the same angular displacements, x is 1-0.5 angular seconds.

Claims (1)

CAPACITIVE MOVEMENT CONVERTER WITH VARIABLE CLEARANCE, containing two flat electrodes mounted with a possibility of angular rotation relative to one another around the axis of rotation, and a measuring circuit connected to them, characterized in that, in order to increase the measurement accuracy by providing an unambiguous direct proportional dependence of the capacitance of the transducer as a function of angular displacement, the axis of rotation is common for both electrodes and is located at the same constant distance from n them, and its center is aligned with the line of intersection of the planes, which are a continuation of the active internal surfaces of the electrodes. .1185069