SU1095075A1 - Oscilloscopic device for measuring single signal duration - Google Patents

Abstract

OSCILLOGRAPHIC DEVICE FOR MEASURING THE DURATION OF A SINGLE SIGNAL, containing a pre-amplification channel, the input of which is connected to the bus of the test signal, a storage cathode ray tube, the signal plates of which are connected to the outputs of the vertical deflection amplifier, and the temporary plates - with the outputs of the horizontal deflection amplifier, the input of which has the ends of the vertical deflection amplifier, and the temporary plates - with the outputs of the horizontal deflection amplifier; With the first output of the scanner, characterized in that, in order to increase the reliability and performance of measurements during reproduction signal using multiple sweeps, it is equipped with a level shaping unit, a modulator, an electronic switch, a frequency multiplier, a recording unit and a shaping selector, the first input of which is connected to the first input of the recording unit, the input of the level shaping unit, the output of the pre-amplification channel and the first the signal input of the electronic switch, the second input — with the second output of the unscrewing unit, the first output — with the second input of the recording unit and the inputs (L frequency multiplier and the rtki, a second output - to the control input of the electronic switch yuvdim whose output is connected to the input amplifiers. l vertical deviation, a second signal input - with the modulator output, the signal input of which is connected to the output of the level-forming unit, and the control input - with the third input of the recording unit O and the output of the frequency multiplier. ate

Description

The invention relates to electrical measuring equipment and can be used to measure the temporal characteristics of photo shutters. An oscillographic device for measuring the duration of a single signal, containing channels of vertical and horizontal deflection, a cathode ray tube and a calibrator Cl of duration, is known. The disadvantage of this device is the low measurement accuracy due to the fact that all measurements of the time interval are made in the area within one stroke of the sweep beam. The closest to the proposed technical entity is an oscillographic device for measuring the duration of a single signal, which contains a pre-amplification channel, the input of which is connected to the signal bus, and the outputs are connected to the inputs of the synchronization unit and the inputs of the delay line. , the outputs of which are connected to the signal plates of the cathode-ray tube, the temporary plates of which are connected to the outputs of the horizontal deflection amplifier, an input connected to the first output of the scanner, the input of which is connected to the output of the synchronization unit, and the second output to the inputs of the backlight amplifier and the output of the delayed unit, amplitude and time calibration, and the control unit 2. The disadvantages of the known device are low reliability and performance of measurements when reproducing a signal using multiple sweeps, due to the ambiguous evaluation of the values of parameters involved in the measurement of the time interval. The purpose of the invention is to improve the reliability and performance of measurements when reproducing a signal using multiple scans. This goal is achieved by the fact that an oscillographic device for measuring the duration of a single signal contains a pre-amplification channel, the input of which is connected to the bus of the signal under investigation, an electron-memory storage tube whose signal plates are connected to the outputs of the vertical deflection amplifier, and the time plates to the outputs the horizontal deflection amplifier, the input of which is connected to the first output of the scanner, is equipped with a level shaping unit, a modulator, an electronic coder a mutator, a frequency multiplier, a registration unit and a selector driver, the first input of which is connected to the first input of the registration unit, the input of the level shaping unit, the output of the pre-amplification channel and the first signal input of the electronic switch, the second input - with the second output of the scanner, the first output - with the second input of the registration unit and the inputs of the frequency multiplier and the scanner, and the second output with the control input of the electronic switch, the output of which is connected to the input of the amplifier vertically deflection signal and the second input - to the output of the modulator, the signal input of which is connected to the output level of the imaging unit, and a control input - to the third input register unit and the output of the frequency multiplier. FIG. 1 shows a structural electrical circuit of the device; in fig. 2 shows timing diagrams in FIG. 3 shows the condition of the image of the signal under study on the ZELT screen. The device consists of a pre-amplification channel 1, a bus 2 of the signal under study, a storage cathode-ray tube (SELT) 3, a vertical deflection amplifier 4, a horizontal deflection amplifier 5, a sweep unit 6, a level shaping unit 7, a modulator 8, an electronic switch 9, frequency multiplier 10, registration unit 11 and selector-generator 12. The input of the pre-amplification channel 1 is connected to the bus 2 of the signal under study, the signal plates of the storage cathode-ray tube 3 are connected to the outputs of the amplification 4, the vertical deflection plates and the time - to the outputs of the horizontal deflection amplifier 5 whose input is connected to the first output scanner 6.

The first input of the selector-generator 12 is connected to the first input of the registration unit 1I, the input of the level shaping unit 7, the output of the pre-amplification channel 1 and the first signal input g of the ectronic switch 9, the second input - with the second output of the sweep 6, the first output - with the second input the recording unit 11 and the inputs of the frequency multiplier 10 and the scanning unit 6, and the second output with the control input of the electronic switch 9, the output of which is connected to the input of the vertical deflection amplifier 4, and the second signal input to the output m blowing torus 8, a signal input coupled to an output of the generating layer 7, and a control input - to a third input of the register 11 and the output of the multiplier 10 frequency.

The device works as follows.

In the initial state, the signal plates of the storage CRT 3 via the vertical deflection amplifier 4, the electronic switch 9, the preamplifier channel 1 are connected to the bus 2 of the signal under study. Block 6 sweep does not work. Before entering the device of the signal under study, the coefficients of the measurement level K y and the scaling of the correction markers K are set, respectively, in block 7, the form factor and the multiplier 10 are equal to the level. The single signal under investigation (Fig. 2a) is amplified in the preamplifier channel 1 to an amplitude suitable for observation on the screen, then through the electronic switch 9 is applied to the vertical deflection amplifier 4, in which the phase voltage applied to the signal CRT plate 3. The CRT 3 screen displays the signal image and the measurement level with markers (Fig. 2a), determines the length of the sweep period Tp and the number of multiplicities p according to the operation of block 6 sweep and The measurement result is t in the registration block 11. At the same time, from the output of channel 1 of the pre-amplification, a part of the signal is removed and fed to the first

the input of the selector-generator 12, which selects the trigger pulse corresponding to the beginning of the arrival of the signal (Fig. 22). This pulse triggers the generator of the sweep unit 6, the sawtooth voltage of which is converted in the horizontal deflection amplifier 5 into paraphase and is fed to the temporary plates of the memory CRT 3. The oscillation amplitude of the sawtooth voltage is set so that the received image of the signal horizontally is convenient for observation.

After the first period of operation of the generator, a pulse is removed from the second output of the sweep unit 6, corresponding to the end of the generator recovery time (Fig. 25). This pulse arrives at the second input of the selector driver 12, passes it and re-starts the generator of the sweep unit 6, the next sawtooth voltage of which continues to reproduce the signal. In the further operation of the scanner unit 6, the mode enters a multiple signal (Fig. 2A), as a result of which the image of the signal under investigation is divided by a multiple of the scanning periods and is superimposed on the screen in parts.

Before the end of the signal under study, the level formation unit 7. the input of which is connected to the output of the pre-amplification channel 1, stores in the pulse expander a constant voltage equal to the amplitude of signal A and divides it by the coefficient of the level ICy to the value A / K h (Fig. 2 a). In the frequency multiplier 10, to the input of which, from the first output of the selectorizer 12, pulses are applied with a frequency equal to the frequency of the sweep start pulses V pi, the frequency is multiplied by the scaling factor Km. At the end of the signal being studied, the selector driver 12 prepares an additional connection between its second output and the input. The next impulse (Fig. 2b), corresponding to the end of the work of the scanner unit 6, passes to the outputs of the selector-generator 12 and simultaneously switches the signal inputs of the electronic switch 9 and controls the scanner unit 6 once. JTOT, on the other hand, blocks the first input and outputs of the selector driver 12, excluding false positives. This stage ends the operation of the scanner unit 6 in the multiple mode, after which it switches to the one-time operation mode, in which it reproduces the image of the measurement level. After the end of the one-shot mode, the sweep unit 6 selects a pulse, which causes the selector driver 12 to return to its initial state. The voltage corresponding to the measurement level from the output of block 7 is fed to modulator 8, modulated by correction markers coming from frequency multiplier 10, and through electronic switch 9 and vertical deviation amplifier 4 goes to signal plates of memory CRT 3, the screen of which reproduces the measurement level with marks. I When reproducing the signal under investigation, the sweep period is set so that on the screen the ends of the side branches (r. 3, point 13) are inseparable until they intersect at point 14 (fig. And the intersection coincides with the measurement level of the duration of the signal under investigation, two equality i - t - and - p t.) duration of the measured signal time interval; the duration of the sweep period; the number of multiplicity of the period of the pitch of the measured interval; K is the number of multiplicity of the period of the screwdriver, the total duration of the signal under study. The registration unit 11 fixes the numerical value of the sweep period Tp according to the starting pulses of the sweep unit 6 coming from the selectorform 121 of the scanner and, during the effect of the signal under study, counts the multiplicity number K. The result of the measurement of the time interval is calculated in block 11 of registration using the formula H Tr - (K-1) If it is difficult to combine the intersection with the level of measurement, the number of correction markers MKVJ (Fig. 3) included in the corrected segment is cut. the side branches of the signal at level-i are not measured, the determination of the sign of the segment according to its location relative to the Intersection, and the input of these results into the registration block 11. Pulses with a frequency of the following correction markers from the output of the frequency multiplier 10 arrive at the registration unit 11, where the duration of the pulse-following period is fixed for the duration of the interval between the markers; scaling factor of correction markers; the duration of the sweep period. The scaling factor of the KM correction markers is chosen so that it is convenient to observe the markers and count them. The time intervals between the markers are not predetermined and not measured. In registration block 11, the correction segment ut, is calculated, which is entered in the measurement result (g, -Mk., L 15). Registration block 11 performs calculations using the formula, i-.j, .iu-A ,. from which it follows that the result of the calculations, with M (y | 0), is only affected by the correct estimate of the length of the krattle number of the sweep period K. For the case of 0, the weight of the value of the correction segment decreases by (K. -1) times. The device allows one to measure the time interval of a single signal directly from the time parameters of the scanner, which eliminated ambiguity in determining the measurement result.

The memory CRT 3 is used as an indicator on which the signal image is recorded qualitatively. The level of measurement of the time interval does not depend on fluctuations in the amplitude of the signal, since it varies in proportion to it. The image is set conveniently for observation and its size does not affect the quantitative characteristics of the signal, i.e. on the measurement results of the duration of the signal. In addition, the measurement results are not affected by the beam drift over time on the screen due to a change in the sensitivity of the tube, zero drift, and a change in gain factors in blocks of deflection systems.

The device allows to increase the reliability, reliability and performance of measurements of the time interval when reproducing the signal under investigation using multiple sweeps.

Claims (1)

Oscillographic device for measuring the duration of a single signal, containing a pre-amplification channel, the input of which is connected to the bus of the signal under study, a cathode ray tube, the signal plates of which are connected to the outputs of the vertical deviation amplifier, and the temporary plates are connected to the outputs of the horizontal deviation amplifier, the input of which is connected with the first output of the scanner, characterized in that, in order to increase the reliability and performance of measurements when playing Using multiple scans, it is equipped with a level forming unit, a modulator, an electronic switch, a frequency multiplier, a recording unit and a selector-shaper, the first input of which is connected to the first input of the registration unit, the input of the level forming unit, the output of the pre-amplification channel and the first signal the input of the electronic switch, the second input - with the second output of the scanner, the first output - with the second input § the house of the registration unit and the inputs of the frequency multiplier and the scanner, and the second output - with the control input of the electronic switch, the output of which is connected to the input - amplify. For vertical deviation, and the second signal input - with the output of the modulator, the signal input of which is connected to the output of the level forming unit, and the control input - with the third input of the registration unit and the output of the frequency multiplier.