SU1205059A1 - Apparatus for measuring relative error of resistive dividers - Google Patents

Description

The invention relates to a measurement technique and can be used to measure and control the errors of resistive current dividers and voltage at various stages of production.

The aim of the invention is to improve the measurement accuracy and expand the functionality of the device by providing measurements of resistive current dividers and voltage.

The drawing shows a functional diagram of the proposed device.

The device contains a voltage source 1, model 2 and test 3 resistive dividers, operational amplifier 4, voltage inverter 5, measuring device 6 switch 7, voltage scaling transducers 8 and 9, two position switches 10 and 11, single Position switches 12 and 13, first, second and third terminals 14, 15 and 16 of the device for connecting the resistive divider under study, the output of source 1 connected to the inputs of scaling transducers 8 and 9, to keys 11 and 12, and the output of scaling transducer 9 connected with inver torus 5 and with keys 10, 12 and 13,

The device works as follows.

When measuring the relative error of current dividers, the device operates in two cycles.

In the first cycle, the key 12 is closed, and the key 13 is open, the on-off keys 11 and 10 connect the measuring device 6 between the outputs of the operational amplifier 4 and the scaling voltage converter B. Switch 7 is set to position 1. The state of the scaling converter 8 is changed until the inputs of the measuring device 6 become equal

Е К «и-Й

where E is the voltage value of the source 55

nickname 1

KVIH inverter transfer ratio of 5,

050592

 fi is the transfer ratio of the pre-processor 8;

ilRi is the resistance ratio of the model divider 2.

5 In the second cycle, key 12 is open, and switch 7 is set to position P. The transmission coefficient of the scaling voltage converter changes until the voltage at the inputs of the measuring device 6 becomes equal to

ten

E I / - sg / l

where s | E is the ratio of the resistances of the investigated divisor 3. After transformations of implications (1) and (2), we obtain

one ,,.

--- RTfRT

Switching using the two-position keys 10 and 11 of the inputs of the measuring device 6 between the input and output of the converter 9, we obtain the voltage difference

thirty

uU E-E m - E 1R3 / R y R1IRZ I (4)

which is directly proportional to the relation error ratio

measurable resistances.

When measuring the relative error of the division factor of the voltage dividers in the first cycle, the keys 12 and 13 are closed, and the two-position keys 11 and Yu connect the inputs of the measuring device 6 between the outputs of the operational amplifier 4 and the voltage scaling converter 8. Switch 7 is set to position W. The state of the voltage scaling converter 8 is changed until the equality

50

R R -t-RZ

(five)

R, if

- dividing ratio of exemplary resistive

divider 2.

In the second cycle, the key 12 is opened, and the switch 7 is set to jV. The state of the scaling converter 9

changes until the measuring instrument 6 has an equality

(6) I pa + Ri

R3

.gb.i-i

 - measured coefficient

 division of the investigated divider voltage.

Switching with the help of two-key switches 10 and 11 inputs of the measuring device 6 between the outputs of the voltage source 1 and the scaling voltage converter 9, we obtain the voltage difference

u, U E-E-m .. (7) After the transformations of expression (6) and taking into account (5), we obtain

, R3 / (RlfCR1 + R2.)

Substituting the expression (8) into (7), we obtain the error of the division factor of the voltage dividers

Y (/ CRb +) 1

 R1 | (R1 + R2) j.

Improving the measurement accuracy is due to the use of two scaling transducers B and 9 voltages with high input resistances, which are made in the form of non-inverting amplifiers, providing a gain factor of both greater and less than one.

As a measuring instrument 6, you can use a digital voltmeter, the scale of which is calibrated in percent.

Claims (2)

1. A device for measuring the relative error of resistive dividers containing a voltage source, the first output of which is connected to the device case, a voltage inverter, an output connected to the input of the model divider and the first terminal of the device for connecting the resistive divider under study, the second terminal which is connected to the first input of the switch, the second input of the model divider connected to the output, the third output of which is 12050594 The third input of the switch is connected to the third terminal of the device for connecting the resistive under study, the divider is the first output of the switch connected to the output of the operational amplifier, the inverting input of which is connected to the second output of the switch (A new key, the movable contact of which is connected to the input of the voltage inversion, the measuring device, the first two-position key and the second one-way key, so that, in order to improve the accuracy of measurements and expand the functional the device’s capabilities, two scaling transducers and the second 2Q is a two-position key, with the second output of the voltage source connected to the bc and scaling limits. educators; with a fixed contact of the first single position key and with the first fixed contact of the second on-off key, the second non-clamped contact of which is connected to the output of the first scaling converter, and the under-contact is connected to the first input of the measuring device, the second input of which is connected to the moving contact of the first on-off key , the first fixed contact of the latter is connected to the output of the operational amplifier, and the second fixed contact is connected to the fixed contact of the second a single-position switch, an inverter voltage input and a second scaling converter code, whose input is connected to the second voltage source output, the moving contact of the second single-position switch is connected to the output of the voltage inverter, and the non-inverting input of the operating amplifier is connected to third g / output switch, extra with extra - output.  2. The device according to claim 1, about t and the current tech that the com-1utator is made in the input of a three-section ite switch, the movable contact of the first section of which is the first The 55 output of the switch, the first and third fixed contacts are the second input of the switch, and the second and chat-fixed contacts are 30 35 40 5, 1205059.6 , with the first input of the comm; utator, and the subcontact of the third section is the viscous contact of the second section of the fourth-fourth input of the switch, the second output of the switch, the first and fourth fixed contacts, the fixed contact of the second second of the second section and the first and second connected to the third fixed contactless third section contact of the third section and is connected to the device body, and the third input of the switch, the second movable contact of the third section the fixed contact of the second section is the third output commutator connected to the fourth fixed frame