SK278162B6 - Connection of capacity to voltage converter - Google Patents

Abstract

Input connector (1) of active filter of 2nd order (1A) is connected the first pole of condenser (C1) and first pole of condenser (C2), at which the second poles of condenser (C1) and condenser (C2) are earthed. On compensating terminal (2,3) of active filter of 2nd order (1A) are connected the resistor (R1) poles and the output terminal (4) of active filter of 2nd order (1A) is connected on input terminal (5) of active filter of 2nd order (1B). On reference terminal (6) of active filter of 2nd order (1B) is connected the pole of condenser (C3), at which the second pole of condenser (C3), is earthed. On compensating terminals (7,8) of active filter of 2nd order (1B) are connected the poles of resistor (R2), at which on output terminal (9) is opposite the earthing terminal (10) of the output electric voltage (U_out).

Description

Technical field

The present invention relates to the field of the art of measuring physical quantities with an intermediate conversion to electrical capacity.

BACKGROUND OF THE INVENTION

In practice, various types of capacitive sensors are often used as sensors of physical quantities. This is because they have little force on the object to be measured, allow non-contact measurement and have a simple design. Their output signal is a varying electrical capacity, which needs to be converted to another type of more advantageously usable electrical signal, for this purpose various types of connection are used, in particular bridge, direct or resonant. Resonance converters of electrical capacity to electrical voltage are preferred with very small capacity changes. However, there are some shortcomings when using classic wiring of this type of converters. In particular, it is necessary to ensure high temperature and time stability of the frequency of the AC power generator, high sensitivity to interfering signals, and also measurement errors caused by the hardly definable capacities of the connection line used between the sensor and the converter.

SUMMARY OF THE INVENTION

The above-mentioned disadvantages are overcome by the connection of an electrical voltage to voltage converter according to the invention, characterized in that the first terminal of the first capacitor and the first pole of the second capacitor are connected to the input terminal of the active second order filter. they are grounded, the second resistor poles are connected to the second order active terminal compensating terminals and the second order active filter output terminal is connected to the second order active filter output terminal, and the third order capacitor first terminal is connected to the 2nd order active filter reference terminal wherein the second pole of the third capacitor is grounded and the poles of the second resistor are connected to the compensating terminals of the active filter of the 2nd order, wherein the output terminal has an electrical voltage against the ground terminal.

Higher effect of wiring of the converter to the electric voltage lies in the identical design of its components, which ensures high temperature and time stability of the converter parameters in integration with the sensor, suppression of measurement errors and low sensitivity to interfering signals.

active filter of 2nd order 1B, capacitor C1, capacitor C2, capacitor C3, resistor R1, resistor R2. The size of the resistor R1 is the active filter of the second order 1A transformed into an alternating current generator, which feeds the active second order filter 1B, whose high value of the quality factor is set by the resistor R2. Capacitor C1 is a capacitive sensor. As its capacity changes, the frequency of the AC signal output signal changes. As a result, the operating point is shifted alongside the modular frequency response of the active second order filter 1B, which results in a change in the output voltage of the second order filter 1B corresponding to the change in sensor capacity.

Industrial usability

In particular, the invention has application in those fields of technology where it is necessary to sense non-electrical quantities and convert them to a precisely defined electrical signal, especially in environments with large fluctuations in the adhesive and in the presence of interfering signals.

Claims (1)

PATENT CLAIMS Connection of an electrical capacitor to an electrical voltage, characterized in that the first terminal of the first capacitor (C1) and the first pole of the second capacitor (C2), the second poles of the first capacitor (1) are connected to the input terminal (1) of the active second order filter (1A). C1) and the second capacitor (C2) are grounded, with the second-order active filter (1A) compensating terminals (2, 3) of the second-order active filter (R1) and the second-order active filter (1A) output terminal (4). is connected to the input terminal (5) of the second order active filter (1B) and the first terminal of the third order capacitor (C3) is connected to the reference terminal (6) of the second order active filter (1B), the second pole of the third capacitor (C3) and the poles of the second resistor (R2) are connected to the compensation terminals (7, 8) of the active second order filter (1B) and the output terminal (9) has an output voltage (Uout) against the ground terminal (10). drawing Overview of the figures in the drawing The accompanying drawing shows the functional diagram of the connection of the converter of the electrical capacity to the voltage. DETAILED DESCRIPTION OF THE INVENTION The connection of the converter to the electric voltage consists of an active filter of the 2nd order 1A, -ffl- / J