SU1018020A1 - Method of stroboscopic conversion of periodic electrical signals - Google Patents

Abstract

A METHOD FOR STROBOSCOPIC CONVERSION OF PERIODIC ELECTRIC SIGNALS, consisting of a signal that transforms this signal asynchronous with the input signal, which reads the discrete values of the signal at the gating moments (sampling), and generates the signal reproduction signal at the times of gating (sampling), which is applied to the input signal reproduction signal. remember all the samples, assigning them i numbers in the order of arrival, -i 1,2, ..., determine the number N of samples and the number Nfi of the extended signals, ene dissolved -i number of each of the samples taken at Ai number which is determined by the formula, ,,), where .1 1,2, ..., x n}; mod is a step-by-step, modulo operation, and reproduce the transformed signal from the samples taken in the conversion interval in the order of the natural increase of the numbers A, A / ji, 1, 2 ,. . . , NB, characterized in that, in order to reduce the acquisition time (L of the transformed signal, the initial sample is used as the initial limit of the conversion interval — the first sample taken at the front of the first expanded signal, and the final limit of the transformation interval is used , taken on the same as the initial, front of one of the subsequent extended signals, the amplitude of which is equal to the amplitude of the 10th initial sample.

Description

This invention relates to electro 1st | measuring technique and can be used to study periodic electrical signals with an unknown period of trace in automatic digital measuring systems .;

The known method C1broscopic oscillography, based | on random coincidence of strobe pulses with a repetition to the trace-I, signal, in which the next | registration of coincidence is performed only when the strobe-pulse + ca coincides with the adjacent interval of the test signal, which is separated from the previous one at a given time interval.

less than 1.; - The disadvantage of this method is the large time of the stroboscopic conversion, due to the fact that the samples of instantaneous values are not carried out for each gate-pulse .;

The closest to the invention of J by the technical essence is | method stroboscopic transform-, | HecHHxpoHt. Mr. with pulse signal :; the conversion of this signal, at which i read the discrete values of the signal at the time of sampling + NIN (sampling), is formed according to the taken | additional samples of a sequence of extended signals, form a L short-sequence reference sequence of pulses with a frequency of,; equal to the frequency of the extended signals, form the conversion interval, as boundaries; who use the closest friend; to a friend, the pulses of coincidence of strobe-i pulses with pulses of the reference sequence are memorized in in-; conversion interval all samples | assigning each sample the number 1 in the order of arrival, i 1r2, |

.. ,, determine Wg, is the number of samples, and Jyq is the number of extended signals; in the conversion interval, each sample with the number i is assigned a number calculated by the formulas h i NV, (Toa NB), where i-. 1,2 ..., | ,; Nej P10 (3 - take modulo,

reproduced the converted signal, by samples taken in the prag interval. education, in the order of the natural; increasing numbers Al, A 1,2, I ..., NftC2l. one

The disadvantage of method 1 is the long preparation time; the converted signal - the time interval from the moment of the start of the conversion to the moment of the end i reproduction of the converted signal. This is due to the fact that the acquisition time of the transformed signal includes the step of waiting for the initial edge of the interval

transformations, in which the pulse of opening a strobe pulse with a short pulse of a reference sequence of pulses, following at a frequency F, equal to the frequency of the propagation of signals, is used. Since the start time of the conversion is independent of the input signal period, the duration of the sleep time can vary from 0 to the value NfiTy, where TH I / FH, and on average is / 2, i.e. half the conversion interval.

The purpose of the invention is to reduce the time to obtain the converted signal.

The goal is achieved in that according to the method of stroboscopic conversion of periodic electric signals, consisting in a pulse conversion of this signal, which is not synchronous with the input signal, which reads the discrete values of the signal sampling elements (the samples7 form a sequence of extended signals on the selected samples of the input signal and form an interval signal transformations in which all samples are stored by assigning numbers to them in the order of arrival, i 1,2, ..., determine the number of NB samples number NM rasrshrennyh signals Hoiep i is replaced with each of the sample taken in, a room A, which is determined by the formula AV -i (vnod Np), where i 1,2 ,,

Ngf mod-modulo, and reproduce the transformed signal from the samples taken in the transformation interval in the order of the natural increase of the AP g numbers Ai l, 2, ..., Ng, use the initial sample - as the initial limit of the conversion interval. the first sample taken at the front of the first extended signal, and the end border of the conversion interval is a sample taken at the same as the initial one, the front of one of the subsequent extended signals, the amplitude of which is equal to the amplitude of the initial signal sampling.

The method is implemented as follows.

The initial sample is selected — the first sample taken at the leading or trailing edge of the first expanded signal, and its amplitude and is remembered. All samples after the initial one are taken, taken further than the strobe pulse, asynchronous with the signal under study, until the final sample is taken. The final sample is determined from the condition that it is taken on the same front of one of the subsequent extended signals as the initial one, and that its amplitude if2 equals the amplitude and initial sample. At the same time, the number of Ng samples taken and the number L of extended signals in the interval between the initial and final samples are measured.

After obtaining the values of Mp and Nj, the sampling is performed, i.e. samples that are naturally numbered in the order of their receipt (the initial sample is assigned the number 1 of the next -.number 2, etc., the i-th number -f, i 1,2, ..., K) are assigned addresses A

(h oaHB)

(one)

If, after the arrangement, we count the samples in the order of the natural increase of the addresses A, i.e. from the sample from А 1 to the sample from AI -Ng, they receive the transformed signal, displaying the form of the tested signal.

 The drawing shows a structural electrical circuit of the device.

The device consists of a strobe-pulse generator, a stroboscopic mixer 2, an amplifier-expander 3, an analog-digital converter (.ATP) 4, a first counter 5 pulses a second counter 6 pulses, a form-ratizer 7 extended signal, a first block 8 of memory , calculator 9, second, memory block 10, trigger 11, difference analysis block 12, initial sample register 13, code comparison block 14, coincidence block 15, subtraction block 16, register 17, and I- element 18.

The device works as follows.

In the initial state, counters 5 and b, trigger 11, registers 13 and. 17, the apparatus of the memory blocks 8 and 10, the computer 9 and the subtraction unit 16 are set to O. Operation. ADC 4, counters 5 and 6 is prohibited. Strobe pulses from generator 1 are fed to the second input of strobe pulse 2, to the first input of which a non-traceable signal is received. At the same time, at the output of amplifier-expander 3, an amplified amplified signal appears. .

At the initial moment, the first control input of the A / D converter 4 receives the Start impulse and allows it to work. At the same time, the digital codes of the samples are sent to the inputs of register L.7, which are written on the falling edge, and to the second inputs of the subtracter 16, which There is no subtraction on the leading edge of the received code: pulses. Thus, block 16 subtracts the following two codes

selections. The difference of the control of these codes is fed to the inputs of the unit 12 for the analysis of the difference, which, if it is not before; equal to zero and the difference modulus exceeds some predetermined value AUyniH g, which is a sign that two successively taken samples lie on the front of the extended signal, produces a pulse, according to which: trigger 11 writes the sign of the difference} in register 13 of the initial sample an initial sample code is recorded with an amplitude U of register 17; counters 5 and b are allowed; into the memory cell with the address it 1 of the first block B the memory is copied from register 13 to the initial sample; The recording of samples into the following cells of the first memory block 8 is permitted.

After this, block 16 and register 17 still form the difference between the amplitudes of the two consecutive samples, counter 5 counts the number of generator pulses 1 (number of samples; counter 6 counts the number of extended signals generated by block 7 by the output signal of the expander-3. of the negative signs in the region of positive values in, memory block 8 records a sample in the order of their arrival, i.e. after recording the normal sample addressres -i to record the next sample increases by 1..

At the same time, unit 14 compares the codes U of the initial sample and the code of the next sample. At the moment of time when a sample was taken with an amplitude of and, AND 0, and under the condition of block 15 matches /, that this sample was taken on the same front as the initial one, i.e. the differences on the output of the subtractor 16 and recorded in trigger 11 are the same, element 18 And generates a signal that prohibits the operation of the ADC 4 and turns on the calculator 9.

The calculator 9 reads from the counters 5 and 6 the numbers of Hg and Ny, respectively the number of samples and the number of extended signals in the interval between the initial and final samples, and from these data the samples are distributed, i.e. addresses. The h, in which the samples were recorded in memory block 8 in the order of arrival, correspond to the address calculated by formula (1). The address A is fed to the address inputs of the second block of 10 memory, and the cell with the address A of the latter is copied from the cell with the address i of block 8 of the memory.

After calculating Ai for -i Ng, the cycrostroscopic conversion is terminated.

To automatically resume the operation of the device, it suffices to sign i NB to submit to the equipment reset to: the initial state and through the element; OR to Bus Start .;

The converted signal, read after completing the arrangement from the second block of 10 memory, by samples in the order of natural increase

addresses A, i displays the form of the signal under study.

The duration of the step of waiting for the initial limit of the transformation interval is a random value and can vary from O to T, on average it is T / 2. Since the waiting step enters at the time of obtaining the transformed singhal, the latter when implementing the reduction method.

Start

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Claims (1)

METHOD OF STROBOSCOPIC CONVERSION OF PERIODIC ELECTRICAL SIGNALS, consisting in the conversion pulse of this signal, which is unsynchronous with the input signal, in which the discrete values of the signal are read at the gates (samples), form a sequence of extended signals from the selected samples of the input signal, which form the conversion interval sampling by assigning them. numbers i in the order of arrival, 4 = 1,2, ..., determine the number of samples and the number M _{n of} extended signals, replace the number 1 of each sample taken with the number Ai, which is determined by the formula A- ^ iNnbnoclNe,), where, ΐ = 1,2 ,. ..,; mod - operation is taken modulo, and the converted signal is reproduced from the samples taken in the conversion interval in the order of natural increase of numbers A _i , Aft. = 1,2, ..., Ν _β, g The relative Leach in that from ¹⁰ to reduce the time of obtaining a transformed signal is used as the initial boundary conversion interval initial sample - the very first sample taken at the front of the first spread signal, , and as the final boundary of the conversion interval, use a sample taken at the same front as the initial one, the front of one of the subsequent extended signals, whose amplitude is equal to the amplitude of the initial sample. SU -1018020