SU1689890A2 - Device for quality control of flat cables - Google Patents

Abstract

The invention relates to a measuring and control technique and can be used to control the quality of flat cables during their manufacture. The aim of the invention is to increase the reliability of the control. The device contains software unit 1, control unit 2, first 4 and second 8 switches providing connection of the object under test 22 to the device, generator 3 test signals, attenuator 9, measuring unit 7, as well as input voltage source 12, comparator 13 and D flip-flop 14. Due to the introduced blocks, the device allows detecting the presence of interferences, which are summed up with the useful signal induced in the control object, and exclude the measurement results in which these interferences are recorded, most increase the reliability of control. The device makes it possible to control the correct positioning of the conductors in the flat cable. 2 Il. w Ё

Description

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The invention relates to a measuring and control technique, can be used to control the quality of flat cables during their manufacture, and is an improvement of the known device according to the author. No. 1318943.

The purpose of the invention is to increase the reliability of monitoring by detecting the presence of interference and eliminating those measurement results in which the interference signal is summed with the induced signal.

FIG. 1 shows a block diagram of the device; in fig. 2 is a timing diagram of the signals, explaining the operation of the device in the measurement cycle,

The device contains software block 1, control block 2, test signal generator 3, first switch 4, including the first 5.1, 5.2, ..., 5.p and second 6.1, ..., 6.n switch groups, measuring unit 7, the second switch 8, which includes the third group of switches 8.1, 8.28.p, attenuator 9, the first 10

and the second 11 resistors, the reference voltage source 12, the comparator 13, the D-flip-flop 14. The control unit 2 contains the input register 15, the distributor 16, the first 17 and the second 18 registers. The measuring unit 7 contains a serially connected differential amplifier 19, the second comparator 20, the indicator 21. Program unit 1 is connected to the input of the register 15, the outputs of which are connected to the input of the distributor 16 and the corresponding inputs of the registers 17 and 18, the other inputs of which are connected to the corresponding outputs of the distributor 16 , and outputs - respectively with the first 4 and second 8 switches. The output of the generator 3 is connected to the attenuator 9 and the closing contacts of the first group of switches 5.1, 5.2, ..., 5.p. Opening contacts first

5.1, 5.25.p and the second 6.1, 6.2b.p groups

The switches are interconnected, with the Corresponding Outputs by the object 22 of the control, containing the chains 22.1, 22.222.п, and through the second resistor with a common terminal. The closing contacts of the second group of switches 6.1, 6.2, ..., 6.n are connected to the first input of the amplifier 19, which is the first input of the measuring unit 7 and the second input of the comparator 13, The output of the attenuator 9 is connected to the second input of the amplifier 19, which is the second input measuring unit 7. The first output of the first resistor 10 is connected to the common output, and the second through the closing contacts 8.1, 8 2, ..., 8.p - with the corresponding outputs of the object 22 of the control. The first input of the second comparator 13 is connected to

the output of the source 12 of the reference voltage, and the output with the C input of the trigger 14, D- whose input is connected to the output of the second comparator 20, the R input with the output of the register 15 and the input of the source 12 of the reference voltage. The output of the trigger 14 is connected to the second input of the indicator 21.

The device works as follows.

From the program block 1, the control unit 2 in the first control cycle receives a signal for setting the zero state of the trigger 14 and switching the switches in the switches 4 and 8. In

The first control cycle includes switches 5.1 and 6.2. In this case, the circuit 22.1 is connected to the output of the generator 3, and the circuit 22.2 is connected to the first input of the unit 7 and the second input of the comparator 13. The remaining circuits of the tested object 22 are connected via the first switch 4 and the second resistor 11 to the common bus.

After this commutation, a induced signal appears in circuit 22.2, due to capacitive coupling between circuits 22.1 and 22.2.

The magnitude of this signal depends on the frequency and amplitude of the signal in circuit 22.1, capacitance between circuits 22.1 and 22.2, capacitance

between circuit 22.2 and common output, input resistances of block 7 and comparator 13. Block 7 compares the amplitude of the induced signal in circuit 22.2 with the threshold voltage Ui (Fig. 2), which corresponds to the induced voltage in the control object with the correct location of the circuits.

If the circuits 22.1 and 22.2 are located next to each other, the signal in the circuit 22.2 exceeds the voltage 111, while the comparator 13 supplies the Goden signal to the indicator. If chains 22.1 and 22.2 are not adjacent, i.e. between them is some other circuit of the object 22 connected to a common terminal, then

the signal level in the circuit 22.2 becomes less than Ui and the comparator 13 generates a Scrap signal.

However, with a higher level of industrial noise, even if the circuits in the cable are entangled, the signal in circuit 22.2 exceeds the voltage Ui, and a false Goden signal is generated. To eliminate this situation, a digital code is supplied to the input of the source 12 of the reference voltage.

5 2, and at the output of the source 12 of the reference voltage, the reference voltage U2 is formed in accordance with the code. The value of LJ2 is theoretically equal to the maximum possible amplitude of the induced signal in the controlled circuit with correctly located conductors and is determined by the formula

C i, i +1

C |, i +1 + C |, +1.0

where Ur is the voltage at the output of the generator 3 of the test signal supplied to the i-th core;

CI.N-I is the capacitance value between 1.1 + 1 chains,

СН-1, о is the value of the capacitance between the (I + 1) -th core and the common conclusion.

The comparator 13 at each excess signal at its second input over the reference voltage U2 generates a single signal (Fig. 2C), which is used to write to the trigger 14 a signal from the output of the comparator 20 of the block 7, coming to its second input (Fig. 2P) and changing its state. From the output of the trigger 14 (Fig. 2Q), the signal arrives at the second input of the indicator 21, and the presence of an increased amplitude of interference is detected, which indicates that the conductors in the cable are incorrectly placed. In the second and

U2

.U1

Induced signal

0

five

0 5

The subsequent control cycles the device works in a similar way.

Claims (1)

The invention improves the reliability of monitoring the correctness of the location of conductors in a flat cable without introducing additional means for organizing statistical processing by fixing the presence of interference in each measurement cycle to subsequently exclude those measurement results in which the interference is summed with the useful signal and thus distorts information about the state of the object . Claims Device for quality control of flat cables according to the author No. 1318943, characterized in that, in order to increase the reliability of the control, an adjustable reference voltage source, a comparator and a D-trigger are introduced, the input of the adjustable reference voltage source being connected to the output of the control unit and the R-input of the D-trigger, and the output with the first input of the comparator, the second input of which is connected to the first input of the measuring unit and the first input of the first switch, the output of the comparator is connected to the C-input of the D-flip-flop. D-input and output of which are connected respectively to the output and the third input of the measuring unit. Yaomeha