SU1177764A1 - Method of measuring phase shift angle between two harmonic signals - Google Patents

Abstract

A METHOD OF GRINDING ANGLE OF SLAVE PHASES BETWEEN TWO HARMONIC SIGNALS, which consists in selecting the transition points by signals of the selected fixed voltage level, harmonic signals of the maximum value, and converting in terms of the torque points DG of the transition through this value of the angle values of the transition angle using the maximum value, converting in terms of the transition moment through the given value of the angle values, transforming in terms of the harmonic signals of the maximum value, converting in terms of the torque points of the transition through this value of the angle values, converting in terms of the harmonic signals of the maximum value, converting in terms of the torque points of the transition through this value of the angle values of the transition angle using the maximum value of the harmonic signals, converting in pulses and calculating the value of the phase shift angle, which is due to the fact that, in order to improve the measurement accuracy, before the moment The transition by each of the two signals of its maximum value makes the first and last for the period of the envelope the transition moments each signal of a fixed voltage level U (j | -p selected within (l-ml.: 2U, where m modulation factor J is the signal amplitude Then, an interval is formed (L of time, between the first and the last for the period of the envelope transition moments of each harmonic signal of a fixed voltage level U (jcp. h h1 h

Description

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The invention relates to a phase-measuring technique and can be used to measure the phase angle between two harmonic signals in the low frequency range.

The purpose of the invention is to improve the accuracy of measuring the phase angle due to the selection of the moment of transition of each of the two signals through the maximum amplitude and the selection of the moments of transitions of amplitude-modulated (AM) signals of fixed voltage levels, after which signals are generated, between which the phase shift is estimated .

The proposed method allows to measure the phase angle of amplitude-modulated signals without demodulation.

Figure 1 shows a device for carrying out the proposed method; Fig. 2 shows timing diagrams of the explanatory work of individual units of the device.

The device consists of linear amplifiers 1 and 2, limiters 3 and 4 signal levels, Schmidt triggers 5 and 6, digital filters 7 and 8, maximum allocation blocks 9 and 10, shock excitation generators 11 and 12, electronic switch 13, reference generator 14 and the registrar 15

The first input of the device is through a serially connected linear amplifier 1, a limiter of 3 signal levels, a Schmidt trigger 5, a digital filter 7, and a maximum extraction unit 9 connected to the first input of the electronic key. 13. The second input of the device through a serially connected linear amplifier 2, a signal level limiter 4, Schmidt trigger 6, a digital filter 8 and a maximum selection block 10 are connected to the second input of the electronic key 13, the third input of the key 13 is connected to the reference generator 14, and the output of the electronic key 13 - to the input of the recorder 15. In this case, the inputs of the generator 11 of the shock excitation are connected to the outputs of the digital filter 7, and the outputs of the generator 11 of the shock excitation - to the third input of the maximum block 9, similarly connected erator 12 to the filter 8 and 10 -b.

Method 5 is carried out as follows.

Amplitude-modulated signals enter the inputs of the linear amplifiers 1 and 2 of each channel, in which the modulation depth increases, then is limited by voltage clamps made, for example, in the form of level limiters 3 and 4, and the level of limitation is selected from the condition

(l-m) Um Uorp modulation factor Un, is the amplitude). As a result, a periodic sequence of the half-wave carrier frequency is formed, the amplitude of which varies according to the AM signal envelope, following the frequency of the modulating signal (Fig. 2).

With the help of shapers, for example, Schmidt's 5 and 6 triggers, the limited signal is converted into an after-; The sequence of packets of square pulses followed by a modulating frequency is fed to the inputs of digital filters 7 and 8, each of which is a binary counter with a set of coincidence circuits (the volume of the counter is chosen from the ratio between the carrier and the modulating frequency). Digital filters 7 and 8 allocate the first and last moments of the output signal AM signal through a fixed voltage level, i.e. the front of the first and the last cut of the pulses of each packet, along which the time interval is formed, the middle of which corresponds to the instant of passage of the maximal point of the AM signal envelope. Blocks 9 and 10 of the maximum of the envelope of the AM signal, gated by the pulses of the generators 11 and 12 of the shock excitation, form short pulses, the instants of appearance, which correspond to the maximum of the enveloping AM signal in each channel. These pulses form a time interval proportional to the shear angle

phases between envelopes.

Electronic key 13: reference oscillator 14 ensures that the allocated time 1Nerval is filled with pulses of the reference frequency. Recorder 15 is an.-Digital computing device. The result should be displayed on the d-screen.

The shear angle is calculated as the product of maintaining the number of pulses ti, proportional to the yrtry phase shift, from

Claims (1)

METHOD FOR MEASURING THE PHASE SHIFT ANGLE BETWEEN TWO HARMONIC SIGNALS, which consists in highlighting the transition moments by the signals of the selected fixed voltage level, highlighting the moments · transitions with harmonic signals of the maximum · value, converting from the moments of transition through this value the phase angle signals into the time interval, filling the time interval with counting pulses and calculating 'the values of the angle of phase shift, which consists in the fact that, in order to increase the measurement accuracy, before selecting the moment of transition and with each of the two signals of its maximum value, the first and last moments of the transition from the envelope to the transition points of each signal with a fixed voltage level (Jofp selected within the limits of (1-hl) .l> _m 4 U _{orp ί} 2U _m , where m is the modulation coefficient; U _m is the amplitude of the signal, then a time interval is formed between the first and last specified for the period of the envelope moments of the transition by each harmonic signal of a fixed voltage level (J _orp . ™ SU about., 1177764 1 1177764 2