SU1456905A2 - Analog meter of small relative difference of speeds - Google Patents

Abstract

The invention can be used in high-precision gauges of small relative velocity difference when measuring stretching, stretching, or strip reduction in the rolling industry, including in reversing mills, and this is an improvement of the device according to the author. No. 1046700. The purpose of the invention is to improve the measurement accuracy. The goal is achieved by introducing a pulse shaping unit 28 of controlled duration, a key 29, and a reference signal setter 30 into an analog meter of a small relative difference of speeds. The meter also contains measuring changes 1, 2, converters 3, 4 speeds to frequency, input frequency pulse shaping unit 5, subtraction unit 6, time interval shaping unit 7, trigger 8, AND-NOT elements 9, And 10, pulse shaping unit 11 the difference frequency, filter 12, keys 13, 14 and an operational amplifier 15. The description shows an example of the execution of block 28. 1 Cp f-ly, 2 ill. with 9 SL lik sd 1H

Description

Ji1.1

The invention relates to electrical measuring technology, can be used in high-precision measuring instruments of small relative difference of speeds in measuring stretching, stretching or strip reduction in a rolling mill (including in reversing mills) and is an improvement of the invention according to the authors. St. 1046700.

The purpose of the invention is to increase the measurement accuracy when measuring the relative difference of linear velocities with the help of measuring rollers.

FIG. 1 shows a diagram of an analog meter of a small relative velocity difference; in fig. 2 is a diagram of a pulse shaping unit of controlled duration.

The device contains measuring rollers .1 and 2, connected to the converters 3 and 4 speeds into a frequency, connected in series to the input pulse shaping unit 5, the subtraction unit 6, the time interval shaping unit 7, the trigger 8, AND-HE elements 9 and 10, a differential frequency current pulse generating unit 11, a CSG filter 12, keys 13 and 14 are connected to an operational amplifier 15, a resistor 16 (R,) and a capacitor 17 in the feedback circuit.

Block 11 contains two differentiating chains 18 and 19, RS-flip-flops 20 and 21, elements And 22 and 23, sources 24 and 25 of current (positive and negative polarities) and keys 26 and 27.

The pulse-shaping unit 28 of controlled duration is controlled by a switch 29 connected to a reference signal adjuster 30 (relative difference in diameters of measuring rollers 1 and 2) and an input of an operational amplifier 15.

The block 28 for shaping the pulses of controlled duration structurally (FIG. 2) consists of frequency dividers 31 and 32, one-shot 33 and 34, RS-flip-flop 35, AND-NE 36 and AND 37 elements, one input of which is connected via a serially connected divider 32, I-NE element 36, RS-trigger 35, one-shot 33 to the output of divider 31, output of element I 37 is connected via one-shot 34 to the input of S-trigger 35, another input is ele.

COP-AND-36 is connected to another input element AND 37.

When measuring the relative difference of linear velocities with respect to the lower speed V, the input of the pulse-shaper unit 28 of controlled duration is connected to the output of the pulse-shaping unit 5 of the input frequencies corresponding to 1m higher speed (Fig. 1).

When measuring the relative difference of the linear speeds with respect to the higher Vj speed, the input of the unit 28 is connected to the output of the input pulse shaping unit 5 corresponding to the lower speed.

Unit 30 of the relative difference between the diameters of the measuring rollers can be made from a constant voltage source and a variable resistor, one of which is connected to the voltage source, and the second is the output of the unit.

The resistance value of the variable resistor is determined based on the fact that the current flowing through the resistor is proportional to the relative difference in diameters of the measuring rollers 1 and 2 (D - Dj) / D, when measuring the relative difference of speeds relative to the lower speed and (D - D) / D when measuring the relative difference in velocity relative to a higher speed. The sign of the absolute diameter difference (Dj - - D,) is given by the polarity of the source voltage of the setpoint device.

A device for measuring a small relative difference of linear velocities (in relation to a lower velocity V in accordance with Fig. 1) works as follows.

If there is a speed difference, the S-input of the trigger 8 from the output of the subtraction unit 6 receives pulses of the Log. O, due to which the state of the Log.O is set at the output of the trigger 8 connected to the input of the AND-9 element. In this case, to the input of the start of the block 7, pulses of a lower frequency {,.

When each pulse of the difference frequency (f - f) appears in block 1.1, trigger 21 switches on input to state Log.1, and trigger 20 on input constantly remains in Log.O. Since the pulses of the difference frequency are repeated pulses of a higher frequency in a period of a lower frequency, at the moment of switching the trigger 21, the output signal of the time interval formation unit 7 corresponds to the signal Log.O. Upon the subsequent launch of block 7 with a pulse of a lower frequency, the signal Log.1 is generated at time t, and through the element 23 it closes the analog switch 27.

The falling edge of the output impulse of the block 7 through the differentiating chain 19 switches the trigger 21 to the initial state, at which the Log.O. signal is set at its output.

During the time t at the difference frequency (f - f) from the current source 25 to the input of the RC filter 12 and then to the input of the operational amplifier 15 receives a current

ex

 loto

(f - f, b

(one)

where 1

- current pulse amplitude

output signal of block 11, simultaneously with the arrival of input frequencies g, the inputs of block 6

l (from block 5) on

and

the subtraction pulses of frequency fJ are also fed to the synchronization input of the pulse-shaping unit 28 of controlled duration — the input of its divider 31, which divides into four. For every fourth pulse arriving at the synchronizing input of block 28, the one-shot 33 switches the RS-flip-flop 35 to the state of a logical unit at its output, allowing the passage of control pulses from block 7 of the meter through the IS-NE 36 element to the divider input 32 frequencies, and this divider switches the first of the passed control pulses (on the falling edge) to the state of the logical unit on its output. In this case, the passage of control pulses through AND 37 to the output of block 28 is permitted, however, since divider 32 switches with the falling edge of the first control pulse, the state of AND 37 does not change, and the initial state of the logical zero remains at its output — the output signal does not is formed. Only the second of the control pulses passes to the output of block 28, and after

35 O 45 50 55

4569034

its termination (on the falling edge) starts the one-shot 34, which by its output signal sets the RS-flip-flop 35 to the state of logical zero by its code, prohibiting the passage of subsequent control pulses to the input of the divider 32.

The divider 32 maintains this state 10 until the arrival of the next synchronizing pulses at the input of the RS flip-flop 35 and the next control pulses after them at the input of the AND-HE element 36.

15 . Thus, at the output of block 28, a sequence of pulses is formed, the duration of which is equal to the duration of the control and mycles (from the output of block 7), and their frequency

20 (average value) is proportional to the frequency of synchronizing pulses (from the output of block 5).

The output signal of the unit 28 is fed to the control input of the switch 29, once the correction current ia passes from the setting device 30. From the output of the switch 29 to the input of the amplifier 15 current pulses are received, the frequency of which is proportional to the higher frequency

30 (2 amplitude is proportional to the relative difference of diameters (D - D) / D, measuring rollers 2 and 1, and the duration of the pulses is equal to the duration t of pulses of the block 7 Average value of the current supplied additionally to the input of the amplifier 15, in this case

i K f P t 1 Mg -gG “o,

(2)

Where

K. coefficient of proportionality. So the input to the amplifier

15 arrives (from the output of block 11 and

key 29) total current

Chh +

1a

ioto (f.

- f,).

K, f,

Da - D D,

(3)

The output voltage of the meter is

and

YOU1

(four)

When choosing K takes the form

 one,

expression (4)

and

off

ioR.6

f - fi

.f.

 -Tg

Br - D,

-)

TO

g - U

V,

(five

. f,

Thus, even with different diameters of the measuring rollers, the output voltage of the proposed device is proportional to the relative difference between the linear velocities V and Vj.

When measuring the relative difference of linear velocities with respect to a higher speed, the operation of the device is similar.

Claims (2)

1. Analog meter of small relative difference of speeds according to auth.St. No. 1046700, characterized in that, in order to improve measurement accuracy, a pulse shaping unit of controlled duration is added to it, the key and the reference signal setter whose output is connected to the first input of the additional key, the input of which is connected to the output fynp. t C & H five 0 five a pulsing unit of controlled duration, the clock input of which is connected to one of the outputs of the input frequency shaping unit, and the control input is connected to the output of the time interval shaping unit, the output of the sub key is connected to the input of the operational amplifier. 2. The meter according to claim 1, which is based on the fact that the pulse shaping unit of controllable duration contains successively sine-blue first frequency divider, first single-oscillator, trigger, IS-NOT element, second frequency division, AND element and the second one-shot, the output of which is connected to the second trigger input, the second gold input AND is connected to the second input of the NAND element and is the control input of the pulse-forming unit of controlled duration, the input of the first frequency divider is the synchronous input of the block and in stroke AND gate is the output of the pulse forming unit controllable duration. . cpuz.z Compiled by R.Matveeva Editor V.Danko Tehred M. Didyk. Order 7549/45 Circulation 711 Subscription VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, 1/5 Raushsk nab. Proofreader A. Obruchar