SU1608591A1 - Apparatus for tolerance check of amplitude-frequency characteristic of fourterminal network - Google Patents

Abstract

The invention can be used for automatic tolerance control of the amplitude-frequency characteristics of quadrupoles. The purpose of the invention is to increase the speed by measuring the coefficient of mutual difference of the reference signal from the output of the reference quadrupole 3 and the signal from the output of the investigated quadrupole 4. For this, shaper 2 rectangular stimulating signals are entered into the device. The output signal of the studied quadrupole through the serially connected first multiplier 5.1, integrator 7.1 and quadrant 8.1 goes to the first input of the adder 9, and through the serially connected second multiplier 5.2, integrator 7.2 and quadrant 8.2 to the second input of the adder 9, the output of which through the gate unit 10 connected to the first input of the controlled voltage divider 11. The second input of the divider 11 is connected to the signal power meter 12, connected to the output of the reference quadrupole, the second input of the second multiplier 5.2, and through the phase shifter 6 to the second input of the first multiplier 5.1. The signal from the output of the controlled voltage divider 11 is fed through the comparator 13 to the first input of the logic processing and display unit 14 and directly to its second input. The control and synchronization of the device is carried out by the control unit 1. 3 il.

Description

The invention relates to instrumentation technology and can be used for automatic tolerance control of the amplitude-frequency characteristic of quadrupoles (AFC).

The purpose of the invention is to increase the speed by measuring the coefficient of mutual difference of the reference and monitored signals 4

Figure 1 shows the structural diagram of the device; Fig. 2 is a block diagram of the control unit; on

Therefore, Yao is connected by a strobe unit 10, a controlled voltage divider 11 and a comparator 13 is connected to the input of the logical processing and display 14.

The control unit 1 comprises a start button 15, an RS flip-flop 16, a clock pulse generator 17, a delay line 18 and a threshold level setting unit 19.

The logic processing and display unit 14 contains a D-flip-flop 20, a light indicator 21 Not normal, 10

fi.Z - block diagram of the logic-15 ° in ° indicator 22 Normally analogous PH1 ... h at ft go-digital converter 23, real-time processing and indication,

The device for tolerance control of AFCS contains a control unit 1, a shaper 2 stimulating signals, a reference one quadrupole 3, a quadrupole under investigation 4, two multipliers 5.1 and 5.2, a phase shifter 6, two integrators 7.1 and 7.2, two quadrants 8.1 and 8.2, an adder 9, gating unit 10, controlled voltage divider 11, signal power meter 12, comparator 13 and logic processing and display unit 14, with the output of the test

memory 24, decoder 25 and digital indicator 26.

20 The stimulating signal generator 2 is a microelectronic device for generating a complex signal, the spectJ: the characteristic S (JCO) of which has the form,

25 close to rectangular (for example, a signal of a series-parallel structure).

The coefficient of mutual difference has the following physical meaning. is he

a quadrupole through a sequence of 30 is a normalized vein connected by the first multiplier 5.1, the first integrator 7.1 and the first quadrant 8.1. connected to the first input of the adder 9, and through the serially connected second multiplier 5.2, the second integrator 7.2 and the second quadrant to the second input of the adder 9 which exit through

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a pattern proportional to the process power at the output of the quadrature correlation device, matched with the reference signal as the monitored signal passes through it. Mathematically, the coefficient of mutual difference is determined by the following expression:

 J Z, (t) Z, (t) Z (t) Z, (t) dtl,

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Therefore, Yao is connected by a strobe unit 10, a controlled voltage divider 11 and a comparator 13 is connected to the input of the logical processing and display 14.

The control unit 1 comprises a start button 15, an RS flip-flop 16, a clock pulse generator 17, a delay line 18 and a threshold level setting unit 19.

The logic processing and display unit 14 contains a D-flip-flop 20, a light indicator 21 Not normal, 10

° C ° indicator 22 Normally, analog-digital converter 23, memory register 24, decoder 25 and digital indicator 26.

The stimulating signal shaper 2 is a microelectronic device for forming a complex signal, the spectrogram J: whose characteristic S (JCO) has the form

close to rectangular (for example, a signal of a series-parallel structure).

The coefficient of mutual difference has the following physical meaning. is he

is a normalized ve

a pattern proportional to the process power at the output of the quadrature correlation device, matched with the reference signal as the monitored signal passes through it. Mathematically, the coefficient of mutual difference is determined by the following expression:

de Z.5 (t), Z (t) - functions of time,

defining structures, respectively, of dz reference and monitored signals;

(t) is a function of time, conjugated by

Gilbert with Z (t);

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T is the duration of the element of the reference signal;

P is the normalization factor;

reference signal power.

The coefficient of mutual difference can also be expressed through spectral functions (by converting

Fourier)

with

 f.5 K (Jt) S; (J) dW

where 8 Oe (s (0) and S, (jO) - complex

spectral functions, respectively, of the reference and monitored signals;

5 (3С4) - function, complex conjugate with S jCjCO);

K - coefficient of normalization.

As can be seen from formula (2), the coefficient g determines the difference in the frequency-Hoij region of the two signals: the reference ZgCt) (at the output of the reference quadrupole, the frequency response of which is uniform

) in the working frequency range) and controlled) Z ,, (t) (at the output it is investigated

 About quadripole).

In the case of the absence of frequency measurements in the studied quadrupole (caused by uneven frequency response),

ke

but

lo $

NA

ge

units1 Signal from direct

RS flip-flop 16 launches

. The output of the generator is 17 clock pulses, the output of which is connected to the delay line 18 and to the driver 2 signal stimuli-HajoB.

Line 18 delay has three outputs connected respectively to the gate unit 10, unit 14 and integrators 7.

The voltage from the direct output of the trigger 16 also includes a block 19 for-. the threshold level, connected by its output to the second input of KoNnapaTopa 13,

Clock pulses from the output of control unit 1 are fed to the input of shaper 2 stimulating signals, from the output of which a complex signal with a rectangular spectral characteristic S (j63) is fed simultaneously to the outputs of the reference and investigated quadripole 3 and 4

The transmission coefficients for quadripoles 3 and 4 are equal, the frequency response of the reference quadrupole 3 is uniform in

: Therefore, signal identities - Z (t) and Z | .. (t) coefficient of mutual difference has the maximum value.

Measurement of the mutual wedge ratio is carried out for the duration of the element of the stimulating signal; at the same time, it is not necessary: in long-term repeated measurements of the signal levels at the output of the quadrupole under study in the frequency range of its operation.

The device works as follows.

When the start button is pressed, the S-ssd of the RS-flip-flop 16 supplies with voltage:, which transfers the RS-flip-16 to the logical state

groove

not working frequencies.

- about - -

ten

15 -

20 - 25

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With the passage of a complex signal through the quadrupole 4 under study, the output waveform is distorted due to the non-linearity of the frequency response.

The reference signal Z (t) from the output of the quadrupole 3 is fed to the first inputs of multipliers 5.3 (via phase shifter 6) and 5.2, (directly). At the second inputs of these multipliers, the monitored signal Z (t) is fed from the output of the quadrupole 4 under study,

The results of the multiplication are fed to the signal inputs of the corresponding integrators 7.1 and 7.2, which are preset by a reset pulse from the fifth output of the control unit 1 to the initial state.

The results of integration are fed through the quadrants 8.1 and 8.2 to the corresponding inputs of the adder-9 and further to the signal input of the gate unit 10.

The gate pulse is fed to the control input of the unit 10 from the fourth output of the control unit 1 at the time of the end of the duration of the element of the stimulating signal.

From the output of block 10, the measurement result is fed to the first input of the controlled voltage divider 11, to the second input of which is fed from the output of the meter 12 connected to the output of the reference quadripole 3, information about the value of the power of the reference signal.

The normalized value of the mutual difference coefficient g from the output 40 1 of the controlled voltage divider 11 is fed to the first input of the comparator 13, which is compared with the threshold value of the mutual difference coefficient of the SPD supplied by the second input of the comparator 13 from the third output of the control unit 1.

The result of the comparison enters the logic processing and display unit 14 at the information input of D-flip-flop 20 in the following form: logical unit — if the measurement result of the mutual difference coefficient is less than the threshold value ()} logical zero — if the measurement result is not less than the threshold value (g Snop).

If the light indicator 21 is turned on Not OK, connected to the direct output of the O-triple 20,

thirty

35

45

50

55

which corresponds to the case of the presence of large frequency distortions in the studied quadrupole, exceeding the established tolerances,

Otherwise, when the indicator light 22 is normal, it indicates a slight frequency distortion of the monitored signal (within the established tolerances) and permissible non-uniformity of the frequency response.

In addition, the measured value of the coefficient of mutual differences is fed to the second input of the block 14 in the analog-to-digital Converter 23.

From the output of the converter 23, the information enters the memory register 24, the outputs of which are connected to the decoder 25, from the output of which the signal goes to the input of the digital indicator 26, which displays the absolute value of the measurement result of the mutual difference coefficient g.

The operation of the D flip-flop 20 and the memory register 24 is controlled by a sync pulse input to the control input of the unit 14 from the first output of the control unit 1.

Claims (1)

Thus, the tolerance control of the amplitude-frequency characteristic of the quadrupole by measuring the mutual difference coefficient of the reference and monitored signals is carried out for the duration of one element of the discrete stimulating signal, which is much faster than in the known device using a oscillating frequency generator. Invention Formula A device for the tolerance control of the amplitude-frequency characteristic of a quadrupole device containing a control unit, a reference four-pole device, a quadrupole under study, a series-controlled voltage divider connected in series, a comparator and a logic processing and indication unit whose control unit is connected to the first output of the control unit, characterized in that, in order to improve speed, a shaper of stimulating signals, connected in series by a phase shifter, the first multiplier itel, first integrator, first quadrant, adder and gating unit, a second multiplier connected in series, a second integrator and a second quadrant as well as a signal power meter, the output of which is connected to the second input of the controlled voltage divider, the output of which is connected to the second input of the logical processing unit and indication, and the second input is connected to the output of the strobe unit, the control input of which is connected to the fourth output of the control unit, the third output of which is connected to the control input to mparatora n ty to strobirunitsim. inputs of the integrators, and the second to the control input of the driver of stimulating signals, the output of which is connected to the inputs of the studied quadrupole, the output of which is connected to the second inputs of the multipliers and the reference quadrupole, the output of which is connected to the power of the signals and the first inputs of the first multiplier. -I M 15 sixteen nineteen b6l.13 Sbggs CH1 17 18 F f y eSfl.l Sat. 65l.1ff 2f f „He 6nb /} / e ., 8 norm 22 26