SU1763869A1 - Device for converting non-electric values in electric signals - Google Patents

Abstract

The invention relates to a measuring and control technology and can be used as a transducer of a non-electric quantity into an electrical signal. The purpose of the invention is to improve the accuracy by expanding the range of linearized sections of the characteristics of the converter. The latter is designed as a super-generator on a transistor with a capacitive feedback, the parameters of which are set so that three linearized sections of the converter with different steepness characteristics are formed. 2 Il.

Description

The invention relates primarily to instrumentation technology and can be used to control dimensions, small displacements, vibration parameters, forces, etc.

A known converter of non-electrical quantities into an electrical signal comprising two high-frequency generators with capacitive differential sensors included in the circuit, a mixer, and a low-pass filter.

The disadvantages of the analogue are low sensitivity and false design.

A transducer of non-electrical quantities into an electrical signal is known, comprising a super-regenerator made on a transistor with a capacitive feedback, and a sensor connected to the positive feedback circuit of the super-regenerator.

The disadvantages of this converter are low accuracy.

The aim of the invention is to improve the accuracy by expanding the range of linearized sections of its characteristics.

This goal is achieved by the fact that in a superregenerative transducer of non-electrical quantities into an electrical signal containing a transistor superregenerator with a capacitive sensor in the positive feedback circuit, the choke is connected to the collector and base power circuit, the capacitance between the base and the emitter of the transistor is variable, one capacitive electrode is grounded and the sensor is configured to discretely change its capacitance.

Figures 1 and 2 show, respectively, a diagram and a characteristic of a super-regenerative converter of non-electrical quantities into an electrical signal.

with

with

VI

ABOUT

with

00 Os

h

A superregenerative converter of non-electrical quantities into an electrical signal contains an autoregenerator supergenerator 1 assembled on a transistor 2 with a capacitive sensor 3 in the positive feedback circuit of the superregenerator 1 connected to one of the plates on the housing and the other plate through the separation capacitor 4 to the transistor collector this emitter the transistor is bridged by a capacitor 5 on the case, and in series with the collector's power supply circuit and the base of transistor 2, a choke 6 is turned on, while the capacitive sensor 3 is sn bzhen mechanism 7 moving one of the plates, which has several adjustable fixed positions.

Superregenerative converter of non-electrical quantities into an electrical signal works as follows.

The high-frequency signal along the positive feedback circuit of the superregenerator 1 at the collector-emitter section passes from the collector of transistor 2 through the capacitor 8 to the emitter of transistor 2, as well as through the coupling capacitor 4 and capacitive sensor 3 to the housing, and then from the housing through the shunt capacitor 5 to the emitter of transistor 2, while the choke prevents the closure of the antiphase high-frequency signal of the positive feedback to the housing. When an external non-electric impact on the capacitive sensor 3, the positive feedback of the superregenerator 1 changes, which leads to a change in the envelope of the free oscillations flashes in the resonant circuit 9 of the superregenerator 1, while the average current consumption of the superregenerator 1 and the output signal of the superregenerator 1, proportional to the current consumption of the superregenerator changes according to the law of change in the external non-electric effect on the capacitive sensor 3. Characteristics of the superregenerative The transducer of non-electric quantities into an electrical signal found experimentally has three sections of characteristics h, 2 and 3 in which the characteristic is linear and in which the coefficient of conversion of non-electric values into an electric signal takes on different maximum values. In this case, the movement mechanism 7 of one of the plates of the capacitive sensor 3 ensures an adjustable fixed position of this plate so that the operating mode of the superregenerative converter is in the area of characteristic h or h

or 3, The movement mechanism 7 of one of the plates of the capacitive sensor 3 can be performed, for example, using a screw pair or a differential screw 5.

The connection of the positive feedback circuit of the superregenerator 1 with the housing allows the use of a capacitive sensor 3, one of the plates of which is connected to the housing, which simplifies the design of the superregenerative converter of non-electric values into an electrical signal, since there is no need for one high-frequency signal.

5 circuit for connecting a capacitive sensor and in isolating one of its plates from the housing.

The ability to change the operating mode of the superregenerative transducer by means of the displacement mechanism 7 of one of the plates of the capacitive sensor 3 allows changing the coefficient of conversion of non-electrical values into an electrical signal K and changing the value of the working section of the superregenerative transducer, which increases the accuracy of the superregenerative non-electrical values into an electrical signal .

0 For a superregenerative converter of non-electric values into an electric signal operating, for example, at a frequency of 60 MHz with a supermerization frequency of 45 HK, the coefficient of conversion of non-electric values into an electric signal K and the working section of the superregenerative converter I were found experimentally: Ki 400 mV / µm, Kg 100 mV / µm,

0 Кз 70 mV / µm, And 5 µm, 2 10 µm and с 20 µm, while the values of K and I change simultaneously with a change in the value of the capacitor C0.

Claims (1)

5 claims A converter of non-electrical quantities into an electrical signal containing a superregenerator, made on a transistor with a capacitive feedback and connected to its output by a capacitive sensor, which, in order to improve the accuracy by expanding the range of the linearized sections of the converter characteristic, equipped with a choke, 5 connected to the collector and base power supply, variable capacitance connected between the base and the emitter of the transistor, one electrode of the capacitive sensor is grounded, the sensor is configured to discretely change its capacitance. L. ± P WX i Fy