SU1234783A1 - Device for measuring resistance - Google Patents

Abstract

The invention relates to a measurement technique and can be used in automatic measurement and control of active resistance systems. The purpose of the invention is to improve the measurement accuracy, achieved by introducing an analog adder 8 into the device. The device also contains measurable resistance 1, resistance of 2 connecting wires, sample resistor 3, measuring voltage gauge 4, amplifier 5, integrating element 6, key 7, the comparator 9, the voltage source 10, the terminal 11 of the initial installation of the device, the output terminal 12. The measured resistance is connected to the terminals 13 and 14. 1 il. (L С 12 IN9 оо 00 со

Description

to

IS

"1234783

The invention relates to the field of measurement technology and can be used in systems for automatic measurement and monitoring of active resistance.

The aim of the invention is to increase the measurement accuracy.

The block diagram shows the device.

The device contains a measurable resistance .1, resistance 2 connecting wires, an exemplary resistor 3, the first terminal of which is connected to the output of the source 4 of the measuring voltage and the first input of the amplifier 5. The output of the amplifier 5 is connected to the input of the integrating element 6, the control inputs of which are connected to the input and output of the key 7, and the first input with the first input of the analog adder 8. The second input of the adder 8 is connected to the output of the integrating element 6, and the output - to the first input of the comparator 9, the second input of which is connected output of source 10 is the reference voltage, the control input yu1f1y key 7 is connected to the input terminal 11, the initial installation device vkod comparator. 9 with an output of 12 devices.

The device works as follows.

In the initial state, the key 7 is closed, the voltage at the output of the integrating element 6 is zero.

Measurement resistance 1 is connected to the terminals 13 and 14 of the device via supply wires with resistances 2. Through the circuit UQ / 1 - - -RX - current

When R About current 1 maximum value

reaches maxi 2g r

The gain of amplifier 5 is selected from the condition

and.

and.

where Ug is the reference voltage of the source 10. Where the coefficient k is equal to

Jk K I.

and

2g + f,

20

The transmission coefficient of amplifier 5 is a constant value (k con8t).

The voltage U at the output of the amplifier 5 with regard to k is equal to

and.

ft

(

2g + R.

) R: I,

IL

0

(2gCh) 1

25

At time t.

 The input signal of the device receives the start of measurement. According to this signal, the switch 7 opens and the process of voltage integration from the output of amplifier 5, proportional to current 1, begins. The voltages from the output of amplifier 5 and from the output of integrating element 6 are summed by an analog adder 8, the output voltage of which is compared with the reference voltage and, “using a comparator 9.

At time tj, the equalities of the voltages at output 1 of adder 8 and and „„ comparator 9: the signal is changed at the output. Time - UQ / 2 flow meter - 40 m Hg moment t to time t, is equal to

(Wo, - U5) c l; CR

Uo

ta - t.

R, 2r К „

de and

g

- measuring voltage source 4;

-measurable resistance 1;

- resistance of two lead wires;

45

It

where k ti PG

c

Measuring time

l f. i-v

R is the value of the resistance of the image;

t with accounting

resistor 3. The voltage drop across resistor 3, proportional to the current Ij, goes to the amplifier 5. At the output of the amplifier, a voltage is formed

and / "kkl ,,

de k - transfer coefficient of the amplifier 5.

With R - O n de accelerator 5 of the source 10. At a voltage of 55, the moment t, equal to the parator 9, is immediately the output, with this at zero.

When R About current 1 maximum value

reaches maxi 2g r

The gain of amplifier 5 is selected from the condition

to

and.

and.

where Ug is the reference voltage of the source 10. Where the coefficient k is equal to

Jk K I.

and

2g + f,

The transmission coefficient of amplifier 5 is a constant value (k con8t).

The voltage U at the output of the amplifier 5 with regard to k is equal to

ft

(

2g + R.

) R: I,

IL

0

(2gCh) 1

At time t.

 The input signal of the device receives the start of measurement. According to this signal, the switch 7 opens and begins the process of integrating the voltage from the output of amplifier 5, proportional to current 1. The voltage from the output of amplifier 5 and from the output of integrating element 6 is summed by an analog adder 8, the output voltage of which is compared with the reference voltage and using comparator 9.

At time tj, the equalities of the voltages at output 1 of adder 8 and and „„ comparator 9: the signal is changed at the output. Vreta - t.

It

k ti const - coefficient

PG

c

proportionality.

Meas time between t and

l f. i-v

eat R value

t taking into account the coefficient k, obtained

When R - O, the voltage and J at the output of the accelerator 5 is equal to the voltage of the Ts. Source 10. As a result of this, the voltage at the output of the adder 8 is 55 moment t, is equal to the voltage U and the comparator 9 immediately changes the output signal, while the duration t is zero.

312347834.

Claims (1)

Claims of the invention - the input terminal of the initial installation devices different A device for measuring resistance is that, in order to improve the accuracy Lennyu containing the key, included the measurement, it introduced an analog a pair of ayol integrating element, a summator, the first input of which is a plug-in adapter, the first input of which is connected to the output of the integrating element, The divine with the output of the source of the second one is connected to the input of the integrator, and the output is connected to the output and the output of the amplifier, and the output is the home of the device, the amplifier, the first to the second input of the comparator, to the first input of which the second is connected to the output of the source of measuring current — the output of the reference resistor, to the input, the model resistor, terminals, the mu input - the first output of the exemplary for charging the measured resistor, the second output of the source, one of which is connected to the measuring voltage, is connected to The first terminal of the reference resistor, 15 the second terminal for connecting the measurement, the control key switch is connected to the seven resistance and to the case. Compiled by V. Savinov Editor L. Avramenko Tezfed V. Kadar Proofreader L. Pigashenko Order 298t / 49; Circulation 728.Subscription VNIIPI Gosuda | "1T9ennrgo Committee of the USSR by do ieobrebeshyy and discoveries 113035, Moscow, Zh-35, Raushsk nab. d 4/5 Production and printing company, Uzhgorod, st. Design,