SU1322221A1 - Device for measuring average period - Google Patents

Abstract

The invention relates to a pulse technique and can be used in devices for automatically measuring the period of a cyclic signal, information processing systems, synchronization devices. The aim of the invention is to improve the accuracy of measuring the average period of a random narrowband signal. To achieve this goal, a counting trigger 5, shapers 6 and 23, 7 and 14 pulses of the falling and leading edges of the signal, respectively, a delay line 10, an OR 11 element, a pulse counter 15, an adder 17, a reversible counter 18, a divider 25 with variable division ratio. In addition, the device contains a pulse former 1, elements 2 and 8, 21 and 22 coincidence, an inverter 3, a reference frequency generator 4, a pulse counter 12, triggers 13 and 19, a pulse generator 20, a period counter 24. The device can organize the measurement of the average period for a given number of periods of the input signal. The measurement error of the device is determined by the number of PD, where n is the number of periods. 3 il. (L with to 1C 1 chE

Description

one

one

The invention relates to a pulse technique and can be used in devices for automatically measuring the period of a cyclic signal information processing systems and synchronization devices.

The aim of the invention is to improve the accuracy of measuring the average period of a random narrowband signal.

Figure 1 shows a block diagram of a device for measuring an average period; figure 2 - timing charts of the device; on fig.Z - timing charts of the device after the arrival of the impulse Poll.

The device contains a pulse shaper 1, a coincidence element 2, an inverter 3, a reference frequency generator 4, a counting trigger 5, a falling front pulse shaper 6, a leading edge pulse shaper 7, coincidence elements 8 and 9, a delay line 10, an OR 11 element, a counter 12 pulses, trigger 13, shaper 14 pulse front edge, pulse counter 15, element 16 coincidence, adder 17, reversible counter 18, trigger 19, pulse generator 20, elements 21 and 22 coincidence, shaper front pulse 23, counter 24 periods and de 25 variable division ratio. Moreover, the input bus through the driver 1 is connected to the second input of the element 2, the first input of which is connected to the forward input of the trigger 19 and the second input of the element 21, the first input of which is connected to the output of the element 16 and the V-input of the adder 17, the outputs of which are connected to the corresponding information the inputs of the reversing counter 18, the subtracting input of which is connected to the C input of the divider 25 and the output of the element 22, the first input of which is connected to the inverse output of the trigger 19 and through the driver 23 to the R-BXO- of the counter 24 and the adder 17, output lementa 2 through an inverter 3 connected to the second input member 8 directly to the first input member 9 through a driver 7 - to

The R-input of the counter 12 and through the form-55 trigger 5. At the end of the input device 6 - to the input of the delay line 10 and the second input of the element 16, the first input of which is connected to the direct output of the trigger 13, whose S-input

pulse in the imaging unit 6 a short pulse is formed on the trailing edge, which through the delay line 10 (Fig. 29) is fed to the control input

1322221

connected to the output of the delay line 10 and the V-input of the counter 15, the D-inputs of which are connected to the corresponding outputs of the counter 12, and the overflow output connected to the R-inputs of the trigger 13 and the counter 15 via the driver 14, the C-input of which is connected to the output of the IPI element 11, the first and second inputs of which are connected respectively to the combined output of the element 9 on the C input of the counter 12 and the output of the element 8, the output of the generator 4 is connected directly to the first input of the element 8 and through the counting trigger 5 to the second input of the element 9, the output of the generator 20 connect ene with the second input member 22, the output of divider 25 is the output bus devices, a bus which is connected to interrogation R-input of flip-flop 19, S-input of which is connected to the output of down counter 18. The borrow apparatus for measuring the average period operates as follows.

In the initial state, the counters 18 and 24 are reset, the adder 17 and the trigger 19 are in the single state.

A random narrowband signal as well as noise is input to the device (Fig. 2c (). Shaper 1, set to a certain threshold voltage, ensures that the signal only passes through the required signal / pgm excess and forms a series of rectangular pulses (Fig. 2-5). The input pulses through the open element 2 coincidence arrive at the element 9 coincidence, the inverter 3, the driver of the trailing edge of the pulse and the driver of the pulse of the leading edge of the 7. At the output of the driver 7 on the leading edge of the input a short pulse is generated (Fig. 2c), arriving at the zero reset input 12. During the input signal pulse, the coincidence element 8 is closed by the signal from inverter 3, and through the open coincidence element 9, pulses are received at the C input of the counter 12 4 pulse generator with frequency divided by

 trigger 5. At the end of the pulse in the shaper 6, a short pulse is formed along the trailing edge, which through the delay line 10 (Fig. 29) is fed to the control input 3132

neither is counter 15, and the contents of counter 12 are rewritten into counter 15.

At the same time, the pulse from the generator 6 goes to the closed coincidence element 16 and through the delay line 10 to the S input of the trigger 13, the control signal from which opens the coincidence element 16, In the pause between the input signal pulses, the coincidence element 9 closes and opened by a signal from the inverter 3, the C-input of the counter 15 through the element OR 11 receives pulses from the generator 4.

When the input signal arrives at the input of the device, the process repeats (on the leading edge the counter 12 is zeroed, the input of the divider 25 arrives at the input of the counters 12 and 15 twice as low as the reference frequency of the generator-20 s) .

On the falling edge of the input pulse, the pulse from the imaging unit 6 arriving through the coincidence element 16, the contents of counter 15 is copied to the adder 17 and the same impulse through the delay line 10, the contents of the counter 12 are copied to the counter 15 (Fig. 2 "J). thirty

At the same time, the pulse arriving at the control input V of the adder from the output of the coincidence element 16, through the open coincidence element 21, enters the C input of the counter 24 periods 35 (Fig. 2g).

Thus, after the end of the second pulse of the input signal, the adder contains the number X proportional to one period of the input signal, and after n periods, which are counted by 24 periods,. adder 17 contains the number

X 21 X ;, where X - the code is long-5

sy from the generator 20. On admission to the subtracting input of the counter 18

P

X Z. T pulses; (fig.Zr) he

zero, and the transfer pulse sets the trigger 19 to one state (Fig. 35), and at the output of the divider 25, the division factor of which is equal to the contents of the counter 24, determined by the pulses arriving at its input (Fig. 3g), P

P

Z T.

t.i

P

pulses (fig.ze),

the number of which determines the average period. When switching the trigger 19 to a single state, the pulse from the driver 23 (Fig. 2e) sets the counter 24 and the adder 17 to the zero state.

It is possible to organize the measurement of the average period for a given number of periods of the input signal. In this case, the end of the measurement is determined by the overflow signal of the counter 24 of the number of periods. The measurement error in both cases is determined by the number Vn.

ti one period.

In the case of a significant fading of the input signal, the time interval between pulses significantly exceeds the period of the input signal. In this case, the counter 15 overflows and the overflow signal enters the front-edge driver 14, which resets the trigger 13 to the zero state.

Counter 15 overflows also occur with a large deviation of the current period from the average, which ensures the selection of the signal at high noise.

As the amplitude of the input signal increases, pulses appear at the output of shaper 1, and the operation of the device repeats.

6, the end of the measurement process, determined by the measurement time,} by the pipulum polling (Fig. 3) at the input of the trigger 19, it switches to the zero state (Fig. 35), and the contents of the sum 17 equal to

h

Z T. Ui

is rewritten to the reversible counter 18. Elements 2 and 21 of the match are closed, and through the open element 22 of the match, to the subtracting input of the counter 18 and to

c-input divider 25 receives impulses

sy from the generator 20. On admission to the subtracting input of the counter 18

P

X Z. T pulses; (fig.Zr) he

the trigger 19 is set to one (Fig. 35), and at the output of the divider 25, the division factor of which is equal to the contents of the counter 24 determined by the pulses arriving at its input (Fig. 3g), P

P

Z T.

t.i

P

pulses (fig.ze),

the number of which determines the average period. When switching the trigger 19 to a single state, the pulse from the driver 23 (Fig. 2e) sets the counter 24 and the adder 17 to the zero state.

It is possible to organize the measurement of the average period for a given number of periods of the input signal. In this case, the end of the measurement is determined by the overflow signal of the counter 24 of the number of periods. The measurement error in both cases is determined by the number Vn.

Claims (1)

Invention Formula A device for measuring the average period, containing a period counter, a first pulse counter, an inverter, three coincidence elements, two triggers, a pulse shaper, a generator reference frequency torus, the output of which is connected to the first input of the first coincidence element, the direct output of the first trigger is connected to the first input of the second coincidence element, the output of which is connected to the input of the inverter, the direct output of the second trigenerator is connected to the first input of the third coincidence element, different the fact that, with the aim of improving the accuracy of measuring the average period of a random narrowband signal, a counting trigger has been entered into it, two back edge pulse formers, two forward front pulse formers, and delays, an OR element, a second counter. pulses, an adder, a reversible counter, a divisor with a variable division factor, three coincidence elements and a pulse generator, the device’s input bus being connected via a pulse shaper to the second input of the second coincidence element whose output is connected to the first input. the fourth element of the match directly, through the first shaper of the trailing edge to the input of the delay line and the second input of the third element of the match, and through the first shaper of the imp Front edge to the R input of the first counter, the C input of which is connected to the output of the fourth coincidence element and the first input of the OR element, the second input of which is connected to the output of the first matching element, the second input of which is connected to the output of the inverter, the output of the OR element connected to C -in the second pulse counter, cat outputs s 0 house ka connected to the information inputs of the adder, the outputs of which are connected to the corresponding inputs of the reversible counter, the subtractive input of which is connected to the output of the fifth coincidence element and the C input of the divider with a variable division factor, the inputs of the division ratio of which are connected to the outputs of the period counter, and the output to the device bus, the output of the reference frequency generator is connected via a counting trigger to the second input of the fourth match element, the outputs of the first pulse counter are connected to There are current D-inputs of the second pulse counter, the V-input of which is connected to the output of the delay line and S to the input of the second trigger, and the overflow output through the second forward pulse generator (connected to the R-inputs of the second trigger and second pulse counter, the output of the third coincidence element is connected to V the input of the adder and the first input of the sixth coincidence element, the second input of which is connected to the forward output of the first trigger, and the output to the C input of the period counter, the R input of which is connected to the R input of the adder and the output of the second form The front-end impulse detector, whose input is connected to the inverse output of the first trigger and the first input of the fifth coincidence element, the second input of which is connected to the output of the pulse generator, the interrogation bus is connected to the R input of the first trigger, whose S input is connected to the output - loan reversing counter 0 five 0 ; f П П ГП П П fill I n p g S  t XR - “X g ro Editor 0. Head Compiled by P. Pletnev Tehred L. Serdyukova Proofreader L. Pilipenko Order 2861/42 Circulation 370Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, Projecto st., 4