SU506108A1 - Frequency Comparison Device - Google Patents

Description

(54) DEVICE FOR COMPARING FREQUENCIES

Pulse voltages (Fig. 2a, b) connected to the signal phases determined by the formers are formed from the harmonic voltage with the frequency / and / 2 entering the input of the formers of pulses / and 2 from the SOURCES of the input signals.

If there is an error in the nominal frequency (for example, i) of one of the compared signals, their phase difference relative to each other continuously changes, which leads to a change in the temporal position of the even (Fig. 2c) and odd (Fig. 2d) pulses relative to the pulses of FIG. 2a

For period T, this relative movement in time is equal to DG k, where LH is the error of period T, T is the real value of the period.

 -t, When moving pulses in time relative to each other, the emulsions alternately coincide first on one of the elements “AND 5 or 6, then on the other.

Their relative mixing, T between two coincidences, occurs over time.

T 2- Considering that T TI ± AG, D / -k

11Д7 Д /

we will receive - - d7 ± 77 77 77

Since -v-; has a value of 10 -10, and

-f- respectively 10-10, then member -

one

neglect, and m --j. H

The pulse durations of FIG. 2a, c, and d are formed on the basis of the maximum value of the difference frequency, i.e., Tp AGtea: s /.

At the outputs of the elements “And 5 YL 6 with coincidence in time of the pulses of FIG. 2a, c and d, pulses appear (fig. 2g), the number of which depends on the duration of the pulses at the inputs of the And 5 elements and the value of the difference frequency.

The first impulses from the output: each of the And 5 and 6 elements change the state of the trigger 10, from the zero output of which a voltage is output (Fig. 2 / s) of duration t.

The output driver J / generates the pulses (FIG. 2L), corresponding in time to the beginning and end of the pulse in FIG. 2k, the repetition frequency of which is A /.

Each of these pulses sets the triggers 12, 13 into a single state, from the single outputs of which the resolving potentials are output to the inputs of the elements "AND 3 and 4. To the other inputs of these elements" And receive the pulses / 2 (Fig. 2fl) and pulses

from the delay line 7 (see Fig. 2d and e), obtained by the time delay of odd impulses / 1 on Tz1 and Tz2, respectively.

When the temporal position of the pulses changes on the output of the delay line 7 (FIG.

 2e and e) with respect to the pulses of FIG. 2a coincidence of pulses in time occurs first on the element “I 4, if the error of the nominal frequency is negative, or on the element“ And 3, if the error is positive.

At the output of the elements "And 5, and at the moments of coincidence," a burst of pulses appear (see Fig. 2h and 2). The first pulses from these packs change the state of flip-flop 5, from the bullet exit, which produces a low potential (see Fig. 2m), corresponding to the sign "-", and a high potential (am. Fig. 2n), corresponding to the sign "-f.

five

. The same pulses return to the original

the zero state triggers 12 or 13, one of which (which gives the inhibitory potential to the corresponding element "AND 3 or 4, in order to exclude a change in the sign in the same period of the signal of the frequency nominal accuracy (see Fig. 2./d).

Claims (1)

Invention Formula A device for comparing frequencies, containing two pulse drivers connected to the corresponding sources of input signals, and four elements “And, one input of each of which is connected to the output of the nerve impulse shaper, while the second inputs of the first and second elements “And are connected to the corresponding taps of the delay line, and the outputs - with zero and single trigger inputs, respectively, characterized in that, in order to increase accuracy, the output of the second driver is connected to the counting input of the second trigger, the zero output of which is connected to the input of the delay line and the second input of the third element "And, and the single output - with the second input of the fourth element “And, while the outputs of the third and fourth elements“ And are connected respectively to the zero and single inputs of the third trigger, the output of which through the output pulse shaper is connected to single and the inputs of the fourth and fifth flip-flops, which are connected to inputs of zero with single and zero inputs of the first trigger, and single outputs with the third inputs of the first and second “H” elements, respectively.