SU1679409A1 - Induction coil parameters transducer - Google Patents

Abstract

The invention relates to test equipment and can be used to obtain information about the parameters of inductors when building systems for the automatic control of parameters of inductors. The purpose of the invention is to improve the accuracy of the conversion. The converter contains the source 1, the test coil 2, the amplifier 3, the resistor 4, the storage elements 5, 6, 7, the zero-organs 8, 9, the key 10, the differentiator 11. The introduction of element 7 and blocks 8, 9 and 10 with their connection allows you to exclude the operation of sequential differentiation from the conversion cycle and the operation of logarithmization. 2 Il.

Description

cl

with

o VI o

fe

about

The invention relates to a measuring and measuring technique and can be used to obtain information about the parameters of inductors, in building systems for the automated control of parameters of inductors.

The purpose of the invention is to improve the accuracy of the conversion.

FIG. 1 shows a structural electrical circuit for converting the parameters of inductors; in fig. 2 - time diagrams that show the work.

The converter of inductance parameters contains the source 1 of the reference voltage, the inductance coil 2 under study, the operational amplifier 3, the resistor 4 (R0), the storage elements 5-7, the first 8 and second 9 zero-organs, the key 10 and the differentiator 11. Source output 1 the reference voltage is connected through the test coil 2 to the inverting input of the operational amplifier 3, in the negative feedback circuit of which resistor 4 is connected, the output of the operational amplifier 3 is connected to the input of the first memory element 5. differential output torus 11 is connected to the input of the third storage element 7, the first control input of the source 1 of the reference voltages is connected to the control input of the first storage element 5, the output of the operational amplifier 3 is connected to the input of the first storage element 5 and the control input of the key 10 directly and through the first the zero-organ 8 with the second control input of the source of the Toporic voltage and with the control input of the key 10, the output of which through the differentiator 11 is connected to the input of the third storage element 7 directly and through Torah zero body 9 to the control input of the second memory cell 6.

Converter parameters of the inductors works as follows.

According to the Start signal, the source 1 of the reference voltages generates a linearly varying voltage Do with a constant time I), which through the test coil 2 is fed to the input of the operational amplifier 3.

The output voltage of the operational amplifier 3 is described by the following expression:

IIftII Cx ° L I I °°

Uoy (t) U0 + U0

Rxru

L

- u.-. R ° Lx P

JO n I

Rxru

The voltage recorded at time t to the first storage element 5,

U33i (t)

CxRc TU

is determined by the value of capacitance - Cx of the investigated coil 2.

At the instant t ti that the signal is zero (Fig. 2) from the output of the operational amplifier (OU) 3, the zero body 8 generates a control signal to the input of the reference voltage source, through which a voltage jump is applied to the input of the amplifier 3 through the test coil 2. Here, the output voltage of amplifier 3 is described by the following expression:

(one

- e

F

Lx

).

The output voltage from the output of the differentiator 11, fixed at the time t Tf by the element 7 (in this case, the implementation of the differential compensation error under the condition td Gf, i.e., by appropriate selection of the storage time of the third storage element 7, is determined the inductance value Lx of the coil 2 under investigation

IZE2 (t)

g - 1f (372)

At the moment when the output signal of the differentiator 11 reaches the zero level t bth, the control signal for the second storage element 6 is generated by the second zero-organ 9, the latter fixes the value of the output voltage of the amplifier 3 proportional to the value of Rx of the coil 2 under study:

U333 (t).

Considering that the time constant of the inductance coil 2 under study is very small (Rx units Ohm), information on the values of the parameters Rx and LX can be obtained almost instantaneously with high

conversion accuracy.

Claims (1)

Claims An Inverter of Parameters of Inductors, Containing a Reference Voltage Source the first terminal for connecting the inductors under investigation, an operational amplifier whose inverting input is the second terminal for connecting the inductors under study and connected in series with the reference resistor and the first storage element whose output is the first output of the converter, the non-inverting input connected to the common bus, a differentiator , the second storage element connected in series, the Start terminal connected to the first control input of the source of the reference voltage and a control input of the first storage element, wherein the output of the second storage element is 4 (t) 0 the second output of the converter, characterized in that, in order to increase the accuracy of the conversion, the first null-organ and the key are connected in series, the third storage element, the output of which is the third output of the converter, and the second null-organ, and the output of the operational amplifier is connected to the inputs of the first null organ, the third storage element and the key signal input, the output of the first null organ is connected to the second control input of the voltage source, the output key is connected to the differential input The detector, the output of which through the second null organ is connected to the control input of the third storage element.