SU1287027A1 - Digital meter of minor variations of period - Google Patents

Abstract

The invention is intended to measure small period deviations. It can be used in conjunction with sensors that have a frequency information output. The purpose of the invention is to improve the accuracy and expansion of functionality. To do this, an additional differentiation circuit 3, elements 2 and 4, period counter 6, controlled divider 11, decoder 12, time stamp bus 19 are also entered into the device. In addition, the device contains driver 1, elements 7, 15 and 2, counters 10, 13, trigger Start 18, one-shot 16, bus General reset 17, generator of exemplary frequency 9, triggers 5 and 14. The discretization error has been reduced, which is caused by the automatic setting of the necessary number of periods. The device can operate in conjunction with an external digital recorder, 2 Il. i (C

Description

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The invention is intended to measure small period deviations and can be used in conjunction with sensors having a frequency information output, in particular, in measuring hydrophysical parameters in the ocean.

The aim of the invention is to improve the accuracy and expansion of functionality.

Figure 1 shows the functional diagram of the device; Fig. 2 shows the voltage plots at the output of its blocks (but the number of diagrams corresponds to the block number).

The meter consists of driver 1, element 2, differentiating circuit 3, element 4, control trigger 5, period counter 6, elements 7 and 8, generator of reference frequency 9, meter of measured value 10, control divider 11, decoder 12, time stamp counter 13, trigger 14, element 15, one-shot 16, tires. General reset 17, Start 18 tires, tires. Time stamp 19.

The meter contains a driver 1, the input of which is the input of the device, a generator of exemplary frequency 9, the output of which is connected to the first input of the first element 7, the output of which is connected to the input of the first counter 10, the Start 18 bus, the one-shot 16 whose output is connected to the common bus reset 17, the second counter 13, which is connected to the first input of the first trigger 14, the output of which is connected to the first input of the second element And 15, the second trigger 5, the first output of which is connected to the first input of the third element And 2, as well as the third sch sensor 6, differentiating circuit 3, fourth 4 and fifth 8 elements And, bus Time marks 19, decoder 12 and controlled divider 11, with the input of the third counter 6 connected to the output of the third element And 2, and the outputs of its bit with. the inputs of the decoder 12, the output of which is connected to the first input of the controlled divider 11, the output of which is connected to the input of the second counter 13, and the second input - ci output of the fifth element I 8, the first input of which is connected to the timestamp bus 19, and the second to the second input of the first element And 7 and the first

the output of the second trigger 5, the second output of which is connected to the input of the one-shot 16, the second input of the second element AND 15 is connected to the first input of the fourth element. AND 4 and the output of the differentiating circuit 3, the input of which is connected to the output of the imager. 1 and the second input of the third element And 2, the bus Start 18 is connected by t second input of the fourth element And 4, the output of which is connected to the first input of the second trigger 5, the second input of which is connected to the output of the second element And 15.

The meter works as follows.

An information sig with a period Tj (fed to the input of imager 1, the output of which is rectangular

pulses with the same period T are formed and fed to the closed element I 2 and differentiating circuit 3, which separates the leading edge of the input pulses. After the input pulse element AND 4 arrives from the external digital recorder, at the moment of its coincidence with the leading edge of the information pulse, the pulse 4 appears at the output of the element 4, which overturns the control trigger 5, which in turn opens the element 2 and measures These pulses start to arrive at the period counter 6,

Thus, synchronization of the start of operation of the external digital recorder and the considered meter, period, is carried out. Simultaneously with the opening of the element And 2

. o Both the elements 7 and 8 are hidden, and the pulses from the generator of the exemplary frequency 9 begin to flow to the counter of the measured value 10, and the pulses of the time stamps to the counting input

controlled divider 11, decoder 12 selects the first period of the measured signal.p, starting simultaneously with the first pulse arriving at the input of the period counter

(FIG. 2 is a time diagram 1 1a 12). The pulse from the output of the decoder enters the control input of the controllable divider 11. In the presence of a pulse at the control input, the division factor is equal to one, and in the absence of SII - three.

Thus, at the moment of the presence of control pulses, the frequency of the marks

3

time at the input of the time stamp counter 13 is three times higher than in their absence. The capacity of the NM of the counter 13 is chosen such that with a longer period of time stamps of the ST, it fills in the time, where Tp is the period of the pulses on the bus.

And this means that when the counter 13 is filled at the time of the first measured period with T time stamps Td, and the rest of the measurement time with the time stamp ST, the overflow pulse of the time counter reads in the time interval from Tp-ZT to Tp-T.

Consequently, at the expiration of the measurement time Tp at the time of the appearance of the overflow pulse, the last period T can be measured completely without distortions and exceeding the time Tp.

In this way, the synchronization of the digital recorder and the considered meter at the end of the measurement time Tp is achieved. The overflow pulse of the counter 13 overturns the RS-flip-flop 14, which opens the element AND 15. After the last measured period is completed, the pulse from the output of the differential circuit 3 through the open element And 15 overturns the trigger 5, and it closes the elements 2, 7 and 8, and in the counter 6 records the number n of measured periods, and in counter 10, where fg is the generator frequency of the reference frequency 9. These values are recorded into a digital recorder and then, using the known n, f and n, the calculation of the period T value is performed, for example, on the computer. .

 After the flip-flop of the flip-flop 5: after a delay time determined by the one-shot 16, the counters 6, 13 and 10 are zeroed, and the RS flip-flop 14 is reset. Then the measurement cycle is repeated.

Thus, the device automatically sets the number of periods n, for which the condition

p, T / - Tr,

which means that the discretization error determined by the expression

but

one

n, t, fo

87027 4

Expansion of functional capabilities Achieved through the ability of the device to work with an external digital recorder.

Claims (1)

Invention Formula A digital period small deviation meter that contains a shaping tel whose input is the input of a gauge, an exemplary frequency generator whose output is connected to the first input of the first element I, whose output is connected to the input of the first counter, the Start bus, a single vibrator whose output is connected with bus General reset, the second counter, the output of which is connected to the first input of the first trigger, the output of which 20 is connected to the first input of the second element And, the second trigger, the first output of which is connected to the first input of the third element And, characterized in that 25 to increase the accuracy of measurement and enhancement of functionality, a third counter, a differentiating circuit, a quarter and a fifth elements H, a time stamp tire, 30 a decoder and a controlled divider, with the input of the third counter connected to the output of the third element I, and the outputs of its bits to the inputs of the decoder, the output of which is connected to the first input of the controlled divider, the output of which is connected to the input of the second counter and the second input - with the output of the first element And, the first input of which is connected to a wide Timestamp, and the second to the second input of the first element And and the first output of the second trigger, the second output of which is connected to the input of the one-vibrator, the second input of the second element And the connection n The first input of the fourth element I and the output of the differentiating circuit, the input of which is connected to the output of the former and the second input of the third element AND, the start bus is connected to the second input of the fourth element I, the output of which is connected to the first input of the second trigger, the second input of which is connected to the output of the second element And FIG. 2