SU406169A1 - DIGITAL FREQUENCY - Google Patents

Description

one

Isob, retention refers to the electrical measuring instrument.

Evbbsten tsnfrovoy MaiCTOTOiMep, which contains an immersion counter of the measured frequency, pulse counters willow 1, and declining of fractional parts and whole periods of the measured frequency, a generator of reference frequencies, triggers, delay elements, and gates.

The proposed frequency: measures differs in that in it the first input of the counter of measured pulses of the measured frequency is connected to the input terminal, the input of the generator and the zero input nepiBoro TRI | PGERA, the second input - to the first: Vykhado; m generator, a single input of the first trigger, through the first the delay element - with the input of the transfer valve of the private and the first input of the private counter and 1 meter; the second delay element - with the reset bus of the drape parts of the period and the zero input of the second control trigger; the second I: of which is connected

to the output of the first trigger and through the valve connected with the in; tori (M output of the DO1M generator, to the first input of the counter of the period parts, the third input to the output of the counter of the fractional part of the period and through the valve connected to the pulse distributor, c the first input of the fractional part register of the measurement result and the second input O4etchi ka private, and the output to the second input of the bank dradnyh parts of the period and through the valve connected to the third output of the generator, to the first input of the period counter and through the valve connected to the second gene output and the output of the period counter, to the input of the distributor of impulses formed by a sequence of delayed delay elements, the outputs of which are connected to wafers connected between bits of counters of fractional parts and whole periods, and through a valve connected through the delay the input terminal, to the C6tpoca bus of full period periods, and the output of the meter is privately connected via the transfer valve private to the second input of the fractional part, the first output of which is connected to the third input of the pulse counter measured frequency.

Such an embodiment of the device makes it possible to increase its accuracy and improve the efficiency of KOHfcTpyiK.

The block diagram of the device) is shown on the drawing.

The digital frequency meter consists on the counter or pulses of the measured frequency for the reference time interval /, the reg fraction of the fractional part of the measurement result 2, the private counter 5, the quantization pulse of the fractional parts of the measured frequency 4, the counter of the quantization pulses of integer periods measured) e frequency 5, the pulse generator of the reference frequency 6, the delay elements 7-10, gates // - 17, triggers 18, 19.

For the measured frequency, the expression is

K + (. R-Ntn Nm) f.

where T is the measurement interval (survey);

L 7 - the number of standard reference frequencies, which are laid down in a part of the period of the measured signal at the beginning of the current measurement interval;

 - collocation: im: the pulses of the reference frequency laid down, c in the period measured from the signal, which coincided with the beginning of the current measurement interval;

 - the number of iashuls of the reference frequency, laid down in a part of the non-period of the measured signal at the end of the current measurement interval; The number of pulses of the reference frequency applied during the period of the measured signal coincided with the frequency of the current measurement interval (this is also the beginning of the Next measurement interval). Generator 6 produces them: 1 reference frequencies / 1, / 2, and / o-fi / 2 f. The frequency pulses / 1 are synchronized with the pulse of the frequency being measured.

The appearance at the generator output of themvtbca of the reference interval and the measurement following at intervals T

- information about the quantizing voltage and the 1P3 pulse frequency of the measured frequency for the reference interval from counter 1 is transmitted to external circuits, and counter 1 is set to 1 and a similar state;

- the signal from delay element 7 transfers the quotient AlrWsT from counter 3 through valve 16 to register 2 of the fractional part of the result of the measured signal, referred to the measurement interval and measured IB at the beginning of the previous measurement interval, and resets the counter 3;

- the signal from the delay element 8, after an interval of / a T, resets the counter 4 and detects the trigger 19, resulting in the closure 14 of the paste;

- the trigger 18 is set to the state, pr: P of which the valve 11 is opened and Ia counter 4, pulses with a frequency / 2 begin to arrive in. measure the number .Vj „

With the arrival of the first after the start of the reference time interval of the Pulse, the measured frequency:

- the trigger 18 is set to NU, with KOTOpOiM the valve 11 is closed

(counter 4; stops counting the number,);

- trigger 19 — to the state in which the valves 13 and 14 are closed, the valve 12 is opened and to the input of the counting: ka 4, a control signal is applied to the switch; The access of quantization pulses to counter 5 is stopped, the division of the number N "in the counter 4 by the number N" in the counter 5 begins by a bit subtraction with the power of the ventals 17 controlled by the distributor on the delay elements 9, which begin to enter through the gate 12 Pulses with frequency / s

After each cycle of the subtraction, the pulse from the output of the last delay element 9 through the valve 15 enters the register 2 for reading and the counter 3 for addition. The division occurs until the trigger of the most significant bit of counter 4 triggers, as a result of which the valve 15 is closed, and the trigger 19 is set to the state in which the valves 13 and 14 are closed again, the valve 12 is closed and the bus control signal is read out and counter 4.

The result of the algebraic difference of the fractional parts of the periods I31 measured at the beginning and IB of the end of the reference measurement interval is output to the external circuits and added to the paiHee output number.

To provide the division operation, the fractional part number .ViT-Wj ,, is recorded in the IB divisible counter as jV.ilO, where n is the number of bits of the fractional part of the result of measuring frequency.

Stust time "T relative to the impulse

the reference time interval is measured, and the delay element 8 generates a signal about the end of the measurement, the counter 4 is reset, and the trigger 19 confirms the state at which the valve 12 is closed, the valves 13 and 14 are open and the tire control number 4 is removed .

From this moment on, counter 5 through impulses 13 receives pulses with a frequency fi. Through the valve 14, the reset pulses 5 are sent to the counter 5, delayed by the element 10 and located in the time between the beginnings of each pulse of the measured sipnal and the first pulse from each synchronized pulse train with a frequency f.

A. The described processes are repeated with the arrival of each pulse of the reference interval.

The connection between the I1Co.m meter 5 and the 12 nip valve is charged to prevent division by zero.

Subject and purpose of (E and

A digital frequency meter containing counters of the measured frequency, counters of MI (quantization pulses of fractional parts and whole periods of the measured frequency, frequency reference generator, triggers, delay elements and gates, in order to improve accuracy and simplify construction, the nepiBbift input of the counter of the measured frequency is connected to the input terminal, the generator input and the zero input of the first trigger, the second input to the first output of the gene, the rator, the single input of the neipiBoro iripger, through the first delay element from to the inputs of the private transfer valve and the output pin of the private counter input and through the second delay element - w; I1Noy of the counter of the fractional parts of the period and the zero input of the second flip-flop trigger; generator, - IK to the first input of the fractional parts counter of the period, the third input - (To the output of the counter of the fractional parts of the period and through the valve connected to the output of the counterparty by it (pulisation) - to the first input of the register of the fractional part of the result

measuring the second input of the quotient counter, and the output to the second input of the fractional parts counter of the period n through a valve connected to the third output of the generator to the first input of the period counter and through the valve connected to the second output of the generator and the output of the period counter, - to the input of a pulse distributor formed in series by Key Delay elements, whose outputs are connected to gates connected between bits of counters of fractional parts and whole periods, and through a gate connected through a delay element ki with the input terminal, - to the reset bus of the counter of integer periods, the output of the private counter is connected via the transfer valve of the private to the second input of the fractional part, the first output of which is connected to the third input of the pulse counter

measured frequency.