SU624114A1

SU624114A1 - Fluid-jet differential sensor

Info

Publication number: SU624114A1
Application number: SU762437729A
Authority: SU
Inventors: Василий Андреевич Исаев; Эдуард Максимович Буйвол; Александр Николаевич Кокарев
Original assignee: Предприятие П/Я А-1701
Priority date: 1976-12-29
Filing date: 1976-12-29
Publication date: 1978-09-15

Description

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Изобретение относитс к области приборостроени и может быть испольН эовано дл измерени неэлектрических величин, осуществл ющих силовое воздействие на упругий элемент датчика.The invention relates to the field of instrumentation and can be used to measure non-electric quantities that force the elastic element of the sensor.

Известен дифференциальный струнный датчик, содержащий две струны, первые концы которых закреплены неподвижно ,а вторые подсоединены к. упруго му элементу датчика,два узла возбуждени частотно-модулированных колебаний каждой из струн,преобразовател колебаний струн в электрические сигналы и усилители, соединенные с выходами соответствующих преобразователей колебаний обеих струн 1 .A differential string sensor is known that contains two strings, the first ends of which are fixed and the second are connected to the elastic element of the sensor, two excitation nodes of the frequency-modulated oscillations of each of the strings, a string oscillation converter into electrical signals and amplifiers connected to the outputs of the corresponding converters vibrations of both strings 1.

Недостатком такого датчика вл етс то, чго в нем имеетс целый р д специальных узлов, два избирательных усилител , сравнивающее устройство, формирователь импульсов и вычитающее устройство, что обуславливает громоздкость и сложность конструкции.The disadvantage of such a sensor is that it has a number of special nodes, two selective amplifiers, a comparing device, a pulse shaper, and a subtracting device, which makes it cumbersome and complex.

Наиболее близким к изобретению по технической сущности вл етс дифференциальный струнный датчик, содержащий две струны, первые концы ;. которых закреплены неподвижно, а вторые подсоединены к упругомуClosest to the invention in its technical essence is a differential string sensor containing two strings, first ends;. which are fixed, and the latter are connected to the elastic

элементу датчика, два узла возбуждени частотно-модулированных колебаний каждой из струн, преобразователи колебаний струн в электрические сигналы и усилитель,соединенный с выходом преобразовател колебаний первой струны 21.the sensor element, two excitation nodes of the frequency-modulated oscillations of each of the strings, transducers of vibration of the strings into electrical signals and an amplifier connected to the output of the transducer of oscillations of the first string 21.

Этот дифференциальный струнный датчик, кроме того, имеет второй усилитель, смеситель частот и фильтр выделени результирующего сигнала.This differential string sensor also has a second amplifier, a frequency mixer, and a result signal extraction filter.

Таким образом,наличие в этом дифференциальном струнном датчике двух усилителей,смесител и фильтра также ведет к усложнению его конструкции .Thus, the presence of two amplifiers, a mixer and a filter in this differential string sensor also leads to a complication of its design.

Целью изобретени вл етс упрощение конструкции датчика.The aim of the invention is to simplify the design of the sensor.

Это обеспечиваетс тем, что в предлагаемом датчике выход усилител подключен к входам узлов возбуждени колебаний струн, а втора струна снабжена элементом настройки частоты его колебаний,обеспечивающим установку частоты автоколебаний первой струны на скате резонансной характеристики второй струны.This is ensured by the fact that in the proposed sensor the output of the amplifier is connected to the inputs of the excitation nodes of the string oscillations, and the second string is provided with an element for adjusting the frequency of its oscillations, providing the setting of the self-oscillation frequency of the first string on the slope of the resonant characteristic of the second string.

Claims

Fig. 1 shows a diagram of the sensor described in Fig. 2 — resonance characteristics explaining the principle of its operation. Differential string sensor Contains two strings 1 and 2, the first ends of which are fixed and the second are connected to the elastic element 3 of the sensor, the excitation nodes 4 and 5 of the frequency-modulated oscillations, respectively, of each of the strings. The sensor also includes converters 6 and 7 of the oscillations of the strings into electrical signals and amplifier 8. The latter is connected to the output of the preamplifier of string 6 1. Amplifier 8 is simultaneously connected to the inputs of the excitation nodes 4 and 5 of the vibration of the strings. In turn, the string 2 is provided with a setting element 9 of its oscillation frequency, which ensures the setting of the frequency of self-oscillations of the string 1 on the slope of the resonant characteristic of the string 2. The device is operated as follows. Since string 2 is the differential half of the sensor, the effect of non-electrical values of P on the elastic element 3 of the sensor causes a shift in its resonance characteristic. Moreover, this snooping occurs in the opposite direction to the change in the frequency of the oscillator, as a result of which an exacerbation of the slope of the resonance characteristic occurs. The initial frequency of the oscillator, in the absence of an effect of a non-electric magnitude P on the sensor, is equal to FC (. This frequency at the output of converter 7 corresponds to the amplitude of oscillations, is equal to the ordinate. the opposite direction (shown in Fig. 2 by a dashed line). Then the amplitude of the oscillations at the output of converter 7 will already be equal to the ordinate B. Thus, the effect is not The electrical value P on the sensor leads to a change in the amplitude of oscillations at the output of the transducer 7 by a value from a to 1. With the opposite direction of influence of a non-electric magnitude P on the sensor, the change in the amplitude of the oscillations at the output of the transducer 7 will be in the other direction. modulation, at its output it is possible to obtain amplitude-modulated oscillations that can be directly used to measure the input quantity P. Claims of the invention a differential string sensor containing two strings, the first ends of which are fixed and the second connected to the elastic element of the sensor, two excitation nodes of the frequency-modulated oscillations of each of the strings, transducers of vibrations of strings into electrical signals and an amplifier connected to the output of the transducer of vibrations of the first string, characterized in that, in order to simplify the device, the output of the amplifier is connected to the inputs of the excitation nodes of oscillations, strings, strings, and the second string is equipped with an element for adjusting its frequency to oscillations, providing self-oscillation frequency setting of the first string on the slope of resonance characteristics of the second string. Sources of information taken into account in the examination: 1. Author's certificate of the USSR W 423045, cl. О 01 Р 3/60, 1972.

2. USSR author's certificate No. 162983, class OIL 5/18, 1963.

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