SU516000A1 - Phase difference meter - Google Patents

Description

one

The invention relates to radio metering technology and can be used in the construction of phase metering equipment, designed to measure small phase differences of periodic sieve in the presence of interference.

The well-known phase difference meter consists of a switch, a phase-lined phase detector, a control trigger and a discriminator, the phase detector being connected to the input sources directly and through a switch that is connected via two inputs to the control trigger and to a synchronous detector connected to selective switching frequency silitel and recording device.

However, in a well-known measurement cell, the frequency of the switching pulses is variable, and therefore, the use of selective amplification during the isolation of small phase differences in the presence of interference is impossible, and therefore the measurement accuracy is not sufficient.

The aim of the invention is to improve the measurement accuracy.

The goal is achieved by the fact that the phase difference meter is equipped with two series-connected single-phase monitors, one of which is connected by two of its inputs to a synchronous detector, a switch and a control trigger, as well as

It is built up with logical three-input elements And, which is connected to the two inputs with the outputs of the single vibrators, and the third with the discriminator.

The functional diagram of the phase difference meter is shown in the drawing.

It consists of a switch 1, a linear phase detector 2, a discriminator 3, a control trigger 4, a logical three-input element AND 5, single-oscillators 6 and 7, a selective switching frequency amplifier 8, a synchronous detector 9 and a recording device 10.

The signals under study are alternately switched at the switching frequency to a linear phase detector 2.

In this case, in a single switching cycle, the signals and and Uz are connected to the phase detector 2, and Uz, and in another cycle, the signal LZ is supplied to the detector inputs. As a result of the switching, the output of the phase detector 2 produces a pulse voltage with a switching frequency and an amplitude that is proportional to the measured phase difference. The selective amplifier 8 selects the first harmonic of the pulse voltage. From the output of the selective amplifier 8, the signal arrives at the synchronous detector 9, the constant component of the output voltage of which is proportional to the phase difference compared to the number of my signals.

3

The generation of the pulses for controlling the switch 1 and the sncrr detector 9 is carried out as follows.

The pulses from the output of the discriminator 3-enter the logical three-input element And 5, open at the initial moment of time on two other inputs. This allows one of the pulses to pass through an open AND5 logical and flip the trigger 4 into the anti-malleable state. The voltage drop of one of the arms of the trigger 4 overturns into an unstable state and a) the time t |, the one-shot 6, after which the further passage of the impulses through the AND 5 element stops. After time: Tb, the one-shot 6 will return to its original state and will overturn in an unstable condition on (rem T2 one-shot 7. After returning the one-shot 7 to the input.m of the element P 5, the SNO is applied opening its voltage. Another impulse from the screamer 3 is deactivated, the input of the tripper 4 and overturns it to its original state.

Since trigger 4 is triggered by pulses corresponding to the moment of transition of one of the input signals through

zero, then the period of the output impulses is a multiple of the frequency of the studied signals. At the same time, the frequency of switching is determined by the time delayed by ti and T2 of single vibrators and constant over the entire range of signals under study.

Ф о р. l and a 3 is found and

A phase difference meter consisting of

a switch, a linear phase detector, a selective switching frequency amplifier, a synchronous detector,) the governing trigger and a discriminator, and the phase detector is connected to the input

signals directly and through a switch that is connected via two inputs to a control trigger and a synchronous detector connected to a selective switching frequency amplifier and registering

device, characterized in that, in order to improve the measurement accuracy, it is equipped with two series-connected single-oscillators, one of which is connected by two of its inputs to a synchronous detector, switch and control trigger, and also has a three-input logical element, which two inputs are associated with single-vibration outputs, and the third with a discriminator.