SU418804A1 - - Google Patents

Description

I

This invention relates to electrical measuring technology.

Known stroboscopic oscilloscope, containing two quartz oscillator frequency, stroboscopic transducer, connected to the amplifier-expander, and the generator of gating pulses.

The time of analyzing oscilloscope signals with quartz oscillators is longer than signal analysis time in conventional stroboscopic oscilloscopes, especially when analyzing signals with a high duty cycle. In conventional stroboscopic oscilloscopes, only a certain segment of the signal period containing the useful information is gated, oscilloscopes with quartz oscillators sequentially gates the entire signal period, and the time spent on gating the pause between pulses of the signal under study is greater, the greater the signal ratio and the smaller the step size readout. This disadvantage is especially pronounced when using stroboscopic transducers in digital signal parameter meters, where the determining factor, along with reproduction accuracy of the signal, is the time spent on measuring parameters.

The aim of the invention is to improve the speed and accuracy of measurement. In order to reduce the analysis time of the studied signals, the proposed device uses gating with variable read steps. Moreover, part of the period of the signal under investigation, containing useful information, is gated with a small read step, which ensures high accuracy of reproduction, and the rest (pause between adjacent pulses), where reproduction accuracy and loss of useful information are unsatisfactory, is gated with a much larger read step.

To achieve this goal, the front-connected front-side selector of the converted signal, two delay circuits and a control unit are introduced into the proposed device. The front edge selector input of the converted signal is connected to the output of the expander amplifier, and the output of the control unit is connected to the inputs of the first and second frequency oscillators. The output of the first delay circuit is connected to one of the inlets of the control unit, and the output of the second quartz frequency generator is connected to the generator of gating pulses.

The drawing shows a block diagram of a stroboscopic oscilloscope.

It contains the first 1 and second 2 crystal oscillators, the strobe pulse generator 3, the stroboscopic converter 4, the expander amplifier 5, the front selector of the transformed signal 6, the first 7 and second 8 delay circuits, and the control unit 9.

The oscilloscope works as follows.

The repetition frequency of the signal under study and the gating pulses are different, so their mutual position changes with each repetition period. As a result, a sequential reading of the instantaneous values of the signal in the stroboscopic converter with a reading pin determined by the value of the difference between the signal repetition frequencies and the gating pulses occurs. The relationship of the read frequency and the magnitude of the difference frequency is determined by the expression

A / I- / s

where: L - reading step;

/ and - the repetition frequency of the signal under study;

/ s is the frequency of repetition of gating pulses;

Af / n- / C-difference frequency.

In the initial period of time, which lasts until the gating moment coincides with the leading edge of the signal under study, the magnitude of the difference frequency is small and the gating is performed with a small reading pin. When the gating moment coincides with the leading edge of the signal under investigation, a selector 6 is triggered, generating a pulse that triggers delay circuit 7. A delay circuit 7 at a time interval equal to the duration of the converted pulse of the signal under investigation produces a trigger pulse of the control unit 9. Up to this point, gating is performed with a small by the reading rod. The start pulse includes a control unit with a small reading pitch. The start-up impulse includes a control unit 9, which abruptly changes the frequencies of the generators 1 and 2, increasing the frequency of the generator 1 and reducing the frequency of the generator 2 so that the magnitude of the difference frequency increases. As a result, the read step is increased. Simultaneously with the launch of the control unit 9, a pulse from the output of the delay circuit 7 starts the circuit

delays 8, which after a certain time interval produces a reset pulse, which arrives at the control unit 9, and returns it to its initial state. As a result, the frequencies of oscillators 1 and 2 return to their original value. The delay value of circuit 8 is chosen such that the frequencies of quartz oscillators 1 and 2 in the control process are set before the next coincidence of gating with

the leading edge of the signal under study. Starting from this point, all processes are repeated as described above.

To get the most time savings when analyzing signals, the step size

reading when gating a pause between adjacent pulses of the signal under study should be maximum taking into account the time of establishing transients during frequency tuning of quartz oscillators.

At the same time, a saving of analysis time can be achieved, equal to half of the signal's duty cycle.

Subject invention

A stroboscopic oscilloscope containing two quartz oscillators of frequency, a stroboscopic converter connected to the amplifier-expander, and a generator

gating pulses, characterized in that, in order to improve speed and accuracy of measurement, the front-connected selector of the converted signal, two delay circuits and

control unit; moreover, the input of the front-edge selector of the converted signal is connected to the output of the amplifier-expander, the output of the control unit to the inputs of the first and second quartz oscillators of frequency; the output of the first delay circuit is connected to one of the inputs of the control unit, and the output of the second quartz oscillator is connected to a gate generator.