SU565391A1 - Digital stroboscopic converter - Google Patents

Description

one

The invention relates to a measurement technique, in particular, to devices for converting the time scale of electrical signals to information outputs in a digital form, and can be used in devices for digitally recording the shape of repeating electrical signals.

Known digital stroboscopic converter containing an analog stroboscopic converter and an analog-to-digital converter 1 connected to it.

The known converter has a large conversion error and comparative complexity.

A strobe digital signal meter is known that compensates for the additive error due to the fact that at each clock cycle the instantaneous value of the signal and the zero level is measured by appropriate sampling phase, and then the code corresponding to the zero level is deducted from the instantaneous value code of the signal under study. The converter contains a strobe-block, made in the form of a serially connected mixer, an expander and a zero-organ (functionally equivalent to an instantaneous value discriminator), a generator of gating and triggering pulses, a digital-to-analog converter and a unit for working off compensating voltages, representing a specialized computing unit containing in particular, a multi-bit adder, a large number of registers and a code converter from binary to binary-decimal. Due to the presence of a computing unit, this converter also allows averaging the measurement result of the instantaneous value of the signal to reduce the random error.

However, the implementation of these operations in a known converter requires large hardware costs, which leads to a significant increase in size, power consumption, noise level.

In order to simplify the converter, two reverse binary and decade counters, two coincidence elements, two switches and a gate are entered, the output of the instantaneous discriminator through the first switch is connected to the counting inputs of the reversible counters, the other inputs of each of which are the control input

the first switch is connected to the first output of the control unit, the code outputs of the reversible meters through the second switch are connected to the input of the digital-to-analog preamplifier, and through the corresponding

elements of coincidence - to the first and second

the valve inputs, the high bit output of the first reversing counter is connected to the third gate input and the second input of the first switch, the high bit output of the second reversing counter is connected to the fourth gate input, the last light input and the third input of the first switch are connected to the second output of the control unit, the output of the valve is connected to the counting input of a decade counter, the other input of which is connected to the second output of the gating generator. And the trigger pulses, which is connected to the third output to the control the second input of the second switch.

The introduction of two reversible counters, two switches, two coincidence circuits, a gate circuit and a decade counter allow one to implement the same algorithm for eliminating additive conversion error as in the known device, with significantly lower hardware costs. This is made possible through the use of both reversible counters, both as feedback and memory elements (when strobe pulses are received), and for performing addition and subtraction operations between the strobe pulses. Since the result is presented in the form of the number of pulses, the type of code in which the result is presented is determined only by the structure of the result counter (in this case, decadal). The accumulation of several measurement results is also simply realized, in particular 10 measurements, for which a decadal frequency divider is introduced into the open circuit of the reset counter of the decade counter.

FIG. 1 is a block diagram of the proposed digital stroboscopic converter; in fig. 2 - time diagrams that show his work.

The digital stroboscopic converter contains (Fig. 1) discriminator 1 of instantaneous values, connected via switch 2 to counting inputs of reversible counters 3 and 4, code outputs of which are connected through switch 5 to digital-to-analog converter 6 (D / A converter), connected to the input of discriminator 1. The code outputs of counters 3 and 4 through the elements of combination 7 and 8 are also connected to the first and second inputs of the valve 9, respectively.

The highest bit of the meter 3 is connected to the third input of the fan 9 or 9 and to eToipoiMy the switch 2 input. Standards 1 time 4 counter DINOn with the fourth input of the valve 9, the fifth input of which And the third input | Cam1 of the switch 2; control unit 10, its other output is connected to the control input of switch 2 and the second inputs of meters 3 and 4. The control unit 10 is connected to one output of the generator 11 of gating and trigger pulses connected to the control input of the ten-day counter 12. Two other outputs generator 11 connected respectively to

the input of the strobe pulses of the discriminator 1 and to the control input of the switch 5. The output of the valve 9 is connected to the counting input of the counter 12.

Work / preformance also (It can be represented in the form of two cycles: the design cycle and the processing cycle | b; from 1Ki.

During the nepiBoro cycle, the generator 11 generates a triggering pulse (Fig. 2, o),

reference and measurable strobe pulses corresponding to the zero and measurable signal value of the signal (Fig. 2.6). At the time of arrival at D1I | OK, the riminator 1 of the reference strobe pulse forms an control loop, which includes discriminator 1, DAC 6 and counter-clock counter 4, and in Momvint, Iv1 meter | str0 (6-pulse - 1 contour from two radiator 1, DAC 6 and rvbvr r 6 | In the “th counter 3.

Revolution meters 3 and 4 are connected to the DAC 6 by a 1M1 switch 5, the control voltage of which has the form shown in FIG. 2, е, and through this, mutator 2 "and inputs for controlling the reversal of both reversible counters 3 and 4 receive signals from discriminator 1 (Fig. 2, d), and to counting inputs -. corresponding to 1I31 measurement and support strobe-pulse pulses, which causes a change in the codes in Accounts Zn4 ± ± 1 in the period of suspension

from the triggering or malfunctioning of the discriminator 1. In the steady state, the codes in counters 3 and 4 correspond to the instantaneous values of the input signal with an accuracy of one less than (heading (without taking into account the polynomialities of the DAC and diagonal driver) Pass: The counters 3 and 4 are indicative.

The processing cycle, which is nominated at the end of the gating pulse gate, consists in filling both reversible counters with a set of high-frequency counting pulses, the number of which is N / 2, where the / V-capacitance of the counter is 3 and 4, while the switch 2 connects the counting inputs counters 3 and 4 to the source | Q and pulses in the control unit, and their inputs, by reversing them, to the output of the most significant bit of the counter 3. The voltage controlling the switch 2 is shown in ph. 2, d The same pmpulse of the block.submits in, hsshch a hundred, rykh bits of both counters 3 and 4 (for 1 Transfer, transfer), which will return the counters 3 and 4, 15 | Output state at the end of H1 11 processing, Imtulsol corresponding to the following;

The processing cycle is also used for the completion of the digital counter 12 in a zero (initial) state.

Let by the time of the beginning of the processing cycle, the counters 3 and 4 are stored respectively

the numbers rti and “2. With both the counting direction of both counters, it becomes reversible, at the outputs of matching circuits 7 and 8, the signal, corresponding to T (Voyu1Shch and the zero state of the counter, CO | В 3 and 4, appears respectively

through "i and" 2 counting pulses (Fig. 2, e,

g), and the number of counting pulses filling the interval mbJ | dui mi (f / ig. 2, h). and arriving at decade counter 12, exactly corresponds to the difference of the codes. IB counts 3 and 4. A similar pattern is found for 1C and three, and, ooaiHaiKo in this case, for counters 3 and 4 is 1 on 1XO | D | Igg1C, an additional code, and the direction of counting of both counters is direct. The sign of the result coincides with h, 1KO (m number in counter 3, if the pulse cxeiMbi coincidence 8 appears first, and the irot is laid to it.

If the sign of the number ni is opposite to the cereal "2", then the counting direction of both counters 3 and 4 also determines 1 with the sign of the number L on the decade counter 12 - the IM1pulBS is received in the intervals from the beginning of the processing cycle to the coincidence element 8 and the pulse processing cycle (phi, r. 2, i), THAT in total is ± (jni | 4- | rt2J) vmrulsov, and the sign is eto (th number of cavas: pad; em with the sign of the number Pi

The operation mode of the valve 9 is determined by the ratio of the states of the highest bits of the counters 3 and 4. When ra (the value of their values, the time interval between the impulses of elements 8 is equal and filled with counting pulses, which is equal to (i.e., subtracting the numbers П and П2, a: at opposite high-order bits, the 1 and 1 M1 pulses are 1M and the two time intervals indicated above are equivalent to the addition of the numbers jni | and | n2.

The result of the 31-year-old in D | military-ten-numbered code X | ra1nit1s in a decade count of 12 to the beginning of the next cycle of processing, ki. If the counter 12 is set to the zero state not at each clock cycle, but through K Tacs (K is any integer), then the measurement result is averaged over the / C-measured values, which decreases (random error and improves the accuracy of measurements). For this purpose, frequency dividers on / C should be connected in series with the counting and setting inputs of meter 12. In the particular case of the (co-integer), it is sufficient to insert a ten-day frequency divider in the meter installation circuit 12 and shift in the meter 12 tenth position for of the PA to nozitsy vigraeo,

In | maintaining additional frequency dividers in a dandy driver, one can achieve not only a reduction in the random error of the signal, but also the digital compensation of the multiplicative error, i.e., the error caused by the inaccuracy of the transfer factor | Dachi interim.

Thus, the construction of the measuring channel of the digital stroboscopic converter according to the proposed structural

scheme allows to significantly simplify the ycfroy while maintaining the functionality of the known device (additive interference and averaging the results of the interference), while eliminating the need for

arithmetic devices additional

memory register and code converter

from binary to binary decimal view.

(In addition, since the measurement result of the instantaneous value of the signals is presented as one or two time intervals, and also as a number and iMipilll00 V, it is not difficult to transmit it via the communication lines on the HH piaocTO.

Claims (2)

1. Description and operating instructions for the oscilloscope strobe-opacic with digital reading C7-7, C79, E1. 406.027 TO, 1975 2. USSR author's certificate No. 292172, cl. G 06J 3/00, 1967.