SU1599804A1 - Apparatus for measuring parameters of two-component two-terminal networks - Google Patents

Abstract

The invention relates to instrumentation technology and can be used in the control and measurement of electrical circuit parameters. The goal — an increase in accuracy — is achieved by reducing the random component of the measurement error by eliminating the operation of differentiating the output voltage over a predetermined time interval. The device contains a control circuit 1, a driver of the reference action 2, a measurement unit 3 consisting of a two-port circuit being investigated, an operational amplifier and a support element, a multiplier 4, a key 5, integrators 6, 7. The device allows to increase the measurement accuracy of the two-pole parameters by eliminating the operation differentiation, increasing random measurement error. 1 il.

Description

(21) 4477845 / 24-21

(22) 08.22.88

(46) 15.10.90. Bul № 38 (72) A. B. -Lebedev, A.I. Ivanov, and Yu.G.Eremeyev

(53) 621.317.377 (088.8)

(56) USSR Copyright Certificate No. 779912, cl. G 01 R 27/00, 1980.

Martushin A.I., Shakhov E.K., Shl ndin V.M. Electrical parameter converters for monitoring and measurement systems. M .: Energie, G975, p. 320.

(54) DEVICE FOR GRINDING PARAMETERS OF TWO-ELEMENT TWO-POLES.

(57) The invention relates to instrumentation technology and can be used in monitoring and measuring electrical circuit parameters. The goal — an increase in accuracy — is achieved by reducing the random component of the measurement error by eliminating the operation of differentiating the output voltage over a predetermined time interval. The device contains a control circuit 1, a driver 2 of the reference action, a measurement block 3 consisting of the two-port circuit being investigated, an operational amplifier and support element, multiplier 4, key 5, integra-. The tori are b and 7. The device allows to increase the accuracy of measurement of the parameters of two-port devices by eliminating the differential (} grading operation, which increases the random measurement error. 2 Il.

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1

ate

 soz

The invention relates to instrumentation technology and can be used in the control and measurement of electrical circuit parameters.

The purpose of the invention is to improve the measurement accuracy by means of excluding a differentiation operation from the device,

Figure 1 shows the structural diagram of the proposed device; figure 2 - time, charts, with -, nyah his work.

The device contains a control unit 1, a driver 2 of reference influence 5, a measurement unit 3, a multiplier 4, a switch 5 and integrators 6 and 7. The measurement unit 3 consists of studying my two-terminal 8, operational amplifier 9 and reference resistive element 10 .

The output of the control unit 1 is connected to the control input of the key 5 and to the driver 2 of the reference action, the output of which is connected to the one input of the multiplier 4 through the block 3 and the key 5 to the second integrator 7. The second input of the multiplier 4 is connected to the driver 2 of the reference impact, and output - with nepBbiM integrator 6.

The device works as follows.

. The shaper 2 of the reference action, according to the signal coming from the control unit 1 (Fig. 2, a), produces a linearly varying voltage, symmetrical with respect to zero (Fig. 2, c):

Ug (t)

S (t - -)

Ufl (t) S (- t)

at t 0.

at t

40

;

(O

, .0,

where S is the slope of the linearly varying stress; I is the time interval corresponding to half the period of a linearly varying voltage.

The output voltage of the measurement unit 3 in the interval t 0 ... C varies according to the law (Lig.2, s)

(t The output voltage of the first integrator 6 is inversely proportional to the resistance RX of the two-port circuit being investigated.

45 Thus, the integrals of the output voltages of the multiplier 4 and the key 5 are proportional to the parameters of the bipolar circuit under study.

Averaging the result due to the integration leads to a decrease in

random error. Choosing an integration time multiple of a harmonic interference period, for example, a network one, can make the meter non-sensitive to strictly periodic interference.

The device can be used (2) but to measure two-terminal parameters with other configurations.

where R ,,, Cj, R

parameters of the measured two-terminal; reference resistance value.

The output signal of the control unit 1 (Fig. 2, a) of the key 5 is opened for the time corresponding to the rise of the linearly varying voltage (t 0 ... T /. The output voltage of the key Up (t) (ig.2e) is integrated by the second integrator 7. The voltage at its output

.and.

J ujt). . dt.

Substituting the expression (2) into this formula, and calculating a certain integral on the interval O ... C, we obtain

at, . j p5.c,, p (--f-5.dt .. (3)

The output voltage of the second integrator 7 is proportional to the capacitance C. The investigated two-port 8.

The output voltage of the multiplier 4 (Fig. 2e) is integrated by the first integrator 6, therefore

ji-l

Ufe S Ju, U, dt LSh S. oUU 2

SRo

 R /

(t -5-) s (t - - | -) dt

/ L -5 fn T5

L oRo

R

51

Claims (1)

In this case, the studied bipolar cells are included either at the input or in the negative feedback circuit of the operational amplifier, A device for measuring parameters of two-element two-terminal devices, comprising a control unit, the output of which is connected to the control input of the key and the input of the driver of the reference action, the output of which is connected to the input of the measuring unit consisting of terminals for connecting the two-terminal device, one of which is input the measuring unit, the other is connected to the inverting input of the operational amplifier willow / / g y, 7 . ll.ll / 998046 and the first pin of the reference resistive element, the second pin of which is connected to the output of the operating room. An amplifier, characterized in that, in order to improve the accuracy, a multiplier, a first and a second integrator are introduced into it, the first input of the multiplier being connected to the input The Q driver of the reference action, the second one with the input of the measuring unit, which is also connected to the signal input of the key, the output of which is connected to the second integrator, the output The J5 multiplier is connected to the input of the first integrator, the outputs of the first and second integrators are the outputs of the device. / /  , 7 .