SU767696A2 - Null indicator - Google Patents

Description

-. ,, -,. one .. . This invention relates to the field of automatics, electrical measuring, and. computer technology and can be used in the construction of high-speed precision analog-to-digital converters and automatic control systems and is an improvement of the known device described in avtoev, 619896. A zero indicator is known, consisting of a wideband non-inverting amplifier with a common deep negative feedback and a positive feedback feedback circuit, capacitive-passband filters, a limiting amplifier, a low-pass filter, a high-frequency filter modulator 1. The disadvantages of this null indicator include low sensitivity stability fixation zero value of the input voltage. In the main invention, according to auth. No. 619896, a null indicator is described containing a modulator made on an empty piece, the two opposite faces of which are input glue, and the register unit in the form of a photocell. the outputs of which through two chains of serially connected pulse generator, differentiating unit and element I are connected to the corresponding inputs of the reversible counter, a source of monochromatic light, in the path of the light flux of which a semi-transparent mirror is installed at an angle of 45 and a fixed mirror. moreover, a semi-transparent mirror is placed between the mirror face of the piezoelectric element, which is located parallel to the light beam of a source of monochromatic light, and the photocell of the recording unit 2.1. The disadvantage of this null indicator is its low speed. The purpose of the invention is to increase the speed of the null organ. This goal is achieved by introducing a nonlinear optical element and an optical filter in a known null indicator, which are installed in series on the path of the light flux of a source of monochromatic light. The drawing shows a functional null indicator circuit. It contains 1, a piezoelectric element 2, a photocell 3 included in the recording unit 4, a source 5 of monochromatic light, a fixed mirror 6, a translucent mirror 7, a nonlinear optical element 8, an optical filter 9.

Input 1 null indicator associated with

two warp-opposite facets of the badging element 2, a third mirror face of which is located opposite the photocell of the 3 registration unit 4. The output of the source 5 of monochromatic light is opposite the fixed mirror 6, and the line connecting the elements 5 and 6 is perpendicular to the line connecting the elements 2 and 3, at the intersection of these directions, a semitransparent mirror 7 is installed at an angle of 45 ° to these directions. Between the source 5 of the light and the semitransparent mirror 7 there are nonlinearly aligned in the same direction th optical element 8 and

optical filter 9. The first output of the photocell 3 is connected to the summing input of the reversible counter 10 through series-connected pulse shaper 11, differentiating unit 12 and element 13. And the second output of the photocell 3 is connected to the subtractive input of the reversing counter 10 through a similar chain of elements. An output p) of the aversive counter 10 is associated with an output 14 of the null indicator.

The null indicator works as follows.

Monochromatic light beam with

wavelength A (shown in dotted lines) from the output of the source 5 of monochromatic light falls on a nonlinear-optical element 8, which generates multiples of the harmonics of the network. The second harmonic with wavelength A / 2 (solid line in the drawing) is separated from the original beam by an optical filter 9. Next, the selected beam is divided into two coherent beams by a semi-transparent mirror 7. The first beam is incident on a fixed mirror 6, reflected from. it, from the translucent mirror 7 and falls on: the input of the recording unit 4; At the same time, the second beam falls on the moving mirror face of the piez.element 2, is reflected from it and, passing through the semi-transparent mirror 7, also goes to the input of the recording unit 4. Since the rays are coherent, then an interferential pattern will be observed at the input of the recording unit 4

Denote by r and tj paths,

which pass the first and second rays of the output line oi of the nonlinear optical element 8 to the input of the recording unit 4. If-: tl (CMS A / 2.), then there will be a maximum

interference, if -4) L is the minimum of interference (m is an integer).

The value of g depends on the magnitude of the deformation of the piezoelectric element 2, which in general is determined by the formula

lg dU,

 I

where lg is the absolute value of the deformation;

d is the coefficient characterizing the inverse piezoelectric effect of the material;

Uj is the input controlled voltage.

Thus, only if there are null-organs at the input 1 of a time-controlled voltage at the input of the recording unit 4, there will be a movement of interference fringes, and at zero voltage at the input 1, there will be no movement of the bands. The alternation of dark-light; the bands are transformed by the photocell 3, the formers of 11 pulses, the differentiating blocks 12, the elements of And 13 and the pulses that go to the sum of the subtracting inputs of the reversible counter 10 depending on the increase or decrease of the input voltage, as well as its field rnness. The zero indicator is adjusted so that in the initial zero state in the reversible counter 10 zero pulses. If there is an input change, the state processes at input 1 in the null-indicator operate the described processes and the reversible counter adds or subtracts the pulses received in the registering body 4 when the interference fringes move. But as soon as the input voltage becomes zero, the vertical counter 10 will again have zero pulses, which is fixed in a certain way at the output 14 of the null indicator.

An advantage of the invention is an increased response rate.

Claims (1)

Invention Formula Zero-indicator on the author; , No. 619896, characterized in that, in order to increase the speed of the null-oncopter it. contains a nonlinear optical element and an optical filter installed in series on the path of the light flux of a source of monochromatic light. Sources of information taken into account in the examination 1, USSR Author's Certificate, 447674, cl, G 05 B 1/01, 24,11,72. 2, USSR Author's Certificate, 619896, cl. G 05 1/00, 28,01,77 (prototype), 767696