SU935811A1

SU935811A1 - Device for automatic measuring of piezoelement resonance and anti-resonance frequency

Info

Publication number: SU935811A1
Application number: SU802992367A
Authority: SU
Inventors: Виктор Прокофьевич Горковенко; Владимир Федорович Елагин
Original assignee: Ростовский Ордена Трудового Красного Знамени Государственный Университет
Priority date: 1980-10-10
Filing date: 1980-10-10
Publication date: 1982-06-15

Description

Изобретение относитс к радиойзмерени м .This invention relates to radio measurements.

Известно устройство дл измерени резонансных частот, содержащее датчик, генератор сигнала с измен емой частотой, блок сервоуправлени , усилитель, синхронный демодул тор, сравнивающее устройство, логический блок, детектор резонанса, счетчик, запоминающее и воспроизвод щее устройства t.A device for measuring resonant frequencies is known, comprising a sensor, a variable frequency signal generator, a servo-control unit, an amplifier, a synchronous demodulator, a comparison device, a logic unit, a resonance detector, a counter, a memory and a reproducing device t.

Недостатком данного, устройства вл етс его сложность.The disadvantage of this device is its complexity.

Наиболее близким по технической сущности к изобретению вл етс устройство дл измерени частоты резонанса и антирезонанса, содержащее генератор измен ющейс частоты, четырехполюсник с измер емым пьезоэпементом , линейный усилитель, амплитудный детектор, электронные ключи, блок пам ти, компаратор, элемент И, блок запуска, генератор пилы и индикатор резонанса, причем генератор иилы соединен с входом генератора измен ющейс частоты и блок запуска, а генератор измен ющейс частоты подключен к четыре;шолюснику , выход которого св зан с компаратором и индикатором резонанса L2.The closest in technical essence to the invention is a device for measuring the resonance frequency and antiresonance, comprising a variable frequency generator, a quadrupole with a measured piezoelectric element, a linear amplifier, an amplitude detector, electronic keys, a memory unit, a comparator, the And element, a trigger unit, a saw generator and a resonance indicator, the generator of which is connected to the input of a variable frequency generator and a start-up unit, and the variable frequency generator is connected to four; the terminal, whose output is connected with a comparator and a resonance indicator L2.

устройству присущи недостаточна точность и сложность. The device lacks accuracy and complexity.

Цель изобретени - повышение точности .The purpose of the invention is to improve accuracy.

Поставленна цель достигаетс тем, что в устройство, содержащее генератор измен ющейс частоты, выходы которого подключены к входам четырехполюсника , в котором установ10 лен измер емый пьезоэлемент, а выходы четырехполюсника через последовательно включенные усилитель, блок пуска и генератор пилообразного напр жени подключены к входам управлени The goal is achieved in that a device containing a variable frequency generator, the outputs of which are connected to the quadrupole inputs, in which the measured piezoelectric element is installed, and the quadrupole outputs, through a series-connected amplifier, start-up unit and sawtooth generator, is connected to the control inputs

15 генератора с измен ющейс частотой, введены фазометр и нуль-орган, причем вход фазометра соединен с одним из выходов четырехполюсника, а выход, фазометра через нуль-орган соединен 15 of the generator with variable frequency, a phase meter and a zero-organ are introduced, the phase meter input is connected to one of the quadrupole outputs, and the phase meter output is connected via a zero-organ

20 с входом управлени индикатора резонанса и входом управлени генератора пилообразного напр жени .20 with a control input of a resonance indicator and a control input of a sawtooth generator.

На чертеже приведена структурна электрическа схема описываемого The drawing shows a structural electrical circuit of the described

25 устройства.25 devices.

Claims

The device contains a generator of 1 variable frequency, a resonance indicator 2, a quadrupole 3 with a measured piezoelectric element (not shown), an amplifier 4, a starting unit 5. generator 6 sawtooth voltage phase meter. 7, a null organ 8. The principle of operation of the device is as follows. When the measured piezoelectric element is connected to the quadrupole 3, the generator b is started and at the output of the generator 1 the frequency of the signals starts to change depending on the change in the level of the signal from the generator b. At the output of the four-port network, the frequency of the signals also changes in accordance with the change in the frequency of the generator 1. The phase meter is connected to a four-pole circuit, measures the phase shift on the measured piezoelectric element and outputs signals to a null organ, the duration of which varies depending on the value phases. At resonance frequencies fp and anti resonance f, the phase shift approaches zero, at which point the null organ 8 is triggered and outputs a signal to the generator 6 and the resonance indicator, while the level of the saw signal is remembered and remains fixed for the time countdown frequency fp or fo The resonance indicator is turned on to measure the frequency. At the end of the measurement, the frequency of the resonance index generates a signal that can be fed, if necessary, to the saw generator for a repeated measurement cycle. The values of the measured frequencies fp fy can be recorded on devices printed in a computer to calculate the parameters obtained on the basis of the measurement of fp and fg. The amplifier serves to amplify and form the level of the signals coming from the output of the quadrupole, the trigger unit serves to generate a single impulse, which starts the generator 6, the phase meter serves to measure the phase shift on the measured piezoelectric element and signage sigissh at zero phase to the zero organ which generates at this time a signal to control the sawtooth generator and the resonance indicator. Introduction of a phase meter and a zero-organ to the device allows to increase the measurement accuracy of the fp parameters and the calculated measurement error in the described device is no more than 0.05%. Apparatus of the Invention A device for automatic measurement of resonance and antiresonance frequencies of a piezoelectric element, comprising a variable frequency generator, the outputs of which are connected to the inputs of the resonance indicator and the quadrupole inputs in which the measured piezoelectric element is installed, and the outputs of the quadrupole through a series-connected amplification gel, start-up and The sawtooth generator is connected to the control inputs of the generator with a variable frequency, characterized in that, in order to improve the accuracy, in it enter us and the zero-phase meter body, wherein the input of the phase meter is connected to one output of the quadripole, and an output F zometra through zero-body is connected to the resonance indicator control input and the control input of the sawtooth generator. Sources of information taken into account in the examination 1. US patent 3,832,630, cl. 324-56, 08.27.7.

2. USSR author's certificate according to the application 2824124 / 18-21, cl. G 01 R 23/00, 09.26.79,