SU1638637A1 - Differential piezoelectric measuring transducer - Google Patents

Description

CM. 2

The invention relates to elements of inertial navigation and automatic control systems and is intended to measure and convert movements, forces or accelerations into an electrical signal,

The purpose of the invention is to improve the measurement accuracy

Fig. 1 shows an electro kinematic circuit of a differential piezoresonance quartz transducer; on figs 2 - view a on fig about 1 about

A differential piezoresonance quartz transducer includes a base 1, in which a piezo-quartz vibrator 3 is rigidly mounted, placed in the gap between the pre-converter plates 2 rigidly connected with each other and movable relative to the base 1, on the plates 2 and the vibrator 3, made respectively of amorphous and quartz crystal, electrodes 4–11 are installed, and electrodes 4, 7, 9, and 10 are located on the vibrator surface, and electrodes 8, 11, 5, and 6 are diametrically opposed These electrodes are electrically in parallel connected to the inputs of the oscillators 12 and 13 of the excitation system so that a pair of electrodes 4 and 8 and a pair of electrodes 7 and 11 of the same group are connected to the oscillator 12, and a pair of electrodes 9 and 5 and a pair of electrodes 10 and 6 of another group — with an autogenerator 13 ”The outputs of the autogenerators 12 and 13 are connected to the inputs of the mixer 14c. In this case, gaps h and h2 are formed between the surfaces of the electrodes 8, 11 and 5, 6 and the corresponding vibrator surfaces, respectively.

I

Differential Piezoresonance

quartz measuring transducer operates as follows

At a zero value of the measured parameter, for example, acceleration, the oscillators 12 and 13 of the excitation system, using electrodes 4-11, excite the electromechanical oscillations of the piezoquartz disk vibrator

25

five

0

20 30 35 40 45

50 55

on two different modes symmetrically localized in the material of the vibrator 3. The gaps between the electrodes 5 and 6, 8 and 11 corresponding to the surfaces of the disk vibrator 3 are equal in size, and the frequencies of the modes are determined accordingly, so that the signal from the output of the mixer 14 corresponds to zero the measured parameter, in this case, the acceleration of the base 1 o If there is an acceleration of the base, the movable plates 2 of the pre-converter, having a mass, together with the electrodes mounted on them, shift relative but the vibrator, respectively, changes by equal magnitudes and gaps h 4 and h2. Similarly, the frequency of the oscillation modes of the piezoresonance quartz transducer varies. The signal from the output of the mixer 14, equal to the difference between these frequencies, is a unique measure of the measured acceleration.

Claims (1)

Invention Formula: A differential piezoresonance quartz measuring transducer containing a base, a pre-transducer, a piezo quartz disk vibrator, an auto-oscillating excitation system of two auto-generators, two groups of electrodes so that, in order to increase the measurement accuracy, the pre-converter is made in the form of two plane-parallel and rigidly connected These plates are arranged with a gap in which a disk vibrator rigidly fixed at the base is symmetrically mounted, in each group two electrodes from different pairs are installed on one surface of the pre-converter plate, two other electrodes from these pairs are installed on the reverse side on the surface of the vibrator, and electrodes from different pairs on the plate and on the vibrator are installed opposite each other.