SU317990A1 - ENTI-TEHIIKK ^ & IBI -] ^ UTENA - Google Patents

Description

The invention relates to the field of phase-measuring technology and can be used to: create high-precision phase meters.

Phase meters are known in which the phase shift of the compared voltages is converted into a proportional ionic direct current, measured by a switch instrument. Such a phase meter contains schemes for the formation of short pulses at times of transition of the compared voltages through zero values and triggers, to the outputs of which a switch indicator is connected, measuring current proportional to the phase shift of the input signals. In this case, the instrument scale is calibrated directly in angular units.

The disadvantage of these phase meters is the presence of measurement error due to the accuracy class of the switch indicator. For example, if the scale of the dial gauge is calibrated within O-180 °, then using a dial gauge, the error of which does not exceed 1%, the maximum error will be 1.8 °. The purpose of the invention is to improve the accuracy of measurement by eliminating the error caused by the presence of a dial gauge.

trigger phase measuring transducer and a compensation device from the nominal phase shift, made of an additional symmetric trigger, dB

frequency dividers, two shapers of short impulses, a phase shifter and a generator; torus fixed frequency.

The drawing shows a block diagram of the npej | i; lagged phase meter.

The phase meter contains the formers / and short pulses, the measuring symmetric trigger 3, the dial indicator 4, the additional symmetric trigger 5, frequency drives 5 and 7, the formers 8 and

short pulses, graduated compensating phase shifter 0, fi: frequency generator //.

Wide-range voltages are often r, the phase difference of which is required to measure, p

step into the input of the formers 1 and 2, the output signals of which represent their own short pointed pulses, the temporal position of which corresponds to the zero-crossing times of the compared signals.

The resulting pulses are used to control trigger.m 3. In this case, its output voltage is proportional to the measurement of my phase difference.

pulses and through graduated compensating phase shifter 10 "and shaper 8 short pulses.

The output voltage of the additional trigger 5, controlled by short pointed pulses from the output of the formers 8 and 9, is proportional to the phase shift of the input currents of these formers, set using a graduated compensating phase shifter 10 in the range of 0-360 °.

Thus, the indication of a switch indicator connected between trigger 3 and additional trigger 5 is proportional to the difference between the first and second stages, of which the first corresponds to the phase shift being measured, and the second to the phase offset set by the graduated phase shifter 10 at a fixed frequency of the generator P.

With equal output voltages of measuring 3 and an additional 5 triggers, an arrow indicator shows “O.

The measured phase shift can be counted on the scale of the graduated phase shifter 10 with a zero reading of a-turn indicator 4. With sufficient sensitivity of the switch instrument, the accuracy of measuring phase shifts does not depend on its class.

In order to reduce the error caused by the nonlinearity of the applied phase shifter, the frequency division of the input voltages of the additional trigger is used with frequency dividers 6 and 7.

Subject matter

An electronic phase meter for measuring the phase shifts of sinusoidal voltages in a wide frequency range, containing a trigger phase-measuring converter and an indicator characterized in that, in order to increase the measurement accuracy,

equipped with a device for compensating the measured phase shift, made in the form of an additional symmetric trigger, frequency dividers, short pulse shapers, a phase shifter and a fixed frequency generator, while the inputs of a symmetric trigger are connected to the generator via frequency dividers and short I1 pulses, one of which is connected a phase shifter, and an arrow indicator is connected between said trigger and trigger phase-measuring converter.