SU1290502A1 - Device for indicating synchronism - Google Patents

Abstract

The invention relates to a pulse technique and can be used in measurement technology, radio engineering, in particular for indicating the tuning of receivers having a phase locked loop. The purpose of the invention is to increase the information content of the indication of synchronization occurrence by ensuring the generation of a discontinuous indicated signal near the capture band, for example, during phase-locked loop. For this, two pulse formers 3 and 5, and a one-shot 6 are additionally introduced into the device. The device also contains an element TRIGGERING OR C trigger 2, element 4, indicator 7, bus 8 of the reference frequency. With a strong mismatch, indicator 7 is almost off. As it approaches synchronization, the indicator switches to flash mode and is turned on when synchronized. 1 il. (L ate che

Description

one

The invention relates to a pulse technique and can be used in measurement technology and in radio engineering, in particular for indicating the tuning of receivers that have a phase locked loop.

 the invention is an increase in the informativity of the indication of entering into synchronism by ensuring the generation of a discontinuous indication signal near the capture band, for example, in devices with phase-locked loop.

The drawing shows the electrical structure of the device.

A synchronization indication device contains an EXCLUSIVE OR element 1, the output of which is connected to the counting input of trigger 2, the output of which is connected to the first input of element 4 through the first driver 3 (short) pulses, the second input of which is connected to the output of the second driver 5 (short) pulses and a reset input trigger 2, the output element And 4 through a single vibrator 6 is connected to the input of the indicator 7, the input of the pulse generator 5 is connected to the reference frequency bus 8 and the first input of the element EXCLUSIVE OR 1, the second input of which is connected inen with a 9 adjustable bus.

The device for indication of synchronization works in the following manner,

Tires 8 and 9 receive impulses of the square wave type, respectively, of the reference and adjustable frequencies, with synchronism between which there is a constant phase shift between the indicated pulses. In this case, at the output of element 1, pulses of twice the frequency appear. These pulses are triggered.

2 on two, highlighted by shaper

The third leading edge arrives at the first input of element 4, the second input of which receives the pulses of the leading edges of the reference frequency allocated by the shaper 5. These same pulses go to the reset input of the trigger 2, ensuring that it starts at the counting input only after the short pulse has been selected by the shaper 5. In the case of frequency matching on buses 8 and 9, the pulses at the inputs of element 4 are shifted in time,

This element 4 has no pulses at its output. In this case, the one-shot 6 is in the initial state and the indicator 7 is turned off.

In the case of a frequency mismatch on buses 8 and 9, the tunable frequency is not equal to the reference frequency, which leads to a change in the frequency of the pulses at the output of element 1. In this

In case of a periodic coincidence of the output pulses of the element 4, the output of which is in the TC pulses. These pulses trigger the one-shot 6, which turns on the indicator 7 for a while.

The frequency of pulses at the inputs of element 4 is determined by the difference between the reference and adjustable

Frequencies: the greater the difference, the more often there is a match. When approaching synchronism, this difference decreases, and pulses coincide less frequently. As a result, when there is a strong detuning, the indicator is turned on almost all the time, as it approaches synchronization, it switches to flash mode, and when it is synchronized, it turns off.

The indicator can be inverted, for example, by inverting the output signal of the one-shot 6.

Claims (1)

Invention Formula 35 55 A synchronization indication device containing an EXCLUSIVE OR element, the first and second inputs of which are connected to the buses, respectively, of the reference and adjustable frequencies, the AND element, the trigger and the indicator, characterized in that, in order to increase the informativity of the synchrophase indication, it is entered two pulse shapers and a one-shot whose output is connected to the input of the indicator, the input to the output of the element I, the first input of which is through, the first driver of the pulses is connected to the output of the trigger, the counting input of which connected to the output of the EXCLUSIVE OR element, the first input of which through the second pulse shaper is connected to the second input of the AND element and the reset input of the trigger.