SU1626168A1 - Method for comparing two sine voltage amplitudes - Google Patents

Abstract

The invention relates to comparing the amplitudes of two sinusoidal voltages of the same frequency and out of phase. The purpose of the invention is to increase speed. Formation of the beginning of the first pulse at the moment of the second zero crossing of the first sinusoidal voltage, relative to which a short pulse is formed, and the end of the second pulse is formed at the moment of the second zero crossing of the second voltage. The device containing the comparators 1-3, at the moment of the first zero crossing of the first voltage, begins to form the beginning of the control time interval, which is converted into the number of pulses that, through element 6 of the pulse generator 13 and frequency divider 14, are stored in counter II. In counter 10, half of the control interval is formed with the aid of element 5, at the end of which a short pulse is generated at the digital comparator 12. elements 4 and 7 also form the first and second pulses, which coincides with one of the short pulses at the output of one of the elements And 8 or 9 the result of the comparison is formed,. 2 Il. (/

Description

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The invention relates to electrical measuring equipment and is intended to compare two sinusoidal voltages of the same frequency and phase-shifted.

The purpose of the invention is to increase speed.

According to the method of comparing the amplitudes of two sinusoidal stresses at the moment of the first zero crossing of the first sinusoidal voltage, when it passes from the negative (positive) region, the beginning of the control interval is formed, the end of which coincides with the first zero crossing of the second sinusoidal voltage positive (negative) area, at the time of the second retracing through the zero of the first sinusoidal voltage form the beginning of the first pulse, the end of which cope with the beginning m of the second pulse and the moment of equality of the first and second sinusoidal voltages, the end of the second pulse coincides with the moment of the second zero crossing of the second sinusoidal voltage, and the ratio of the amplitudes of the compared voltages is determined by coincidence with the first or second pulses of a short pulse, formed at the moment of time, which is half the control interval of time from the moment of the second zero crossing of the first sinusoidal voltage.

Figure 1 shows an example of a device implementing a method for comparing amplitudes; figure 2 - diagram for example.

The device for comparing the amplitudes of two sinusoidal voltages contains comparators 1-3, elements AND 4-9, counters 10 and 11, digital comparator 12, pulse generator 13, frequency divider 14, reset element 15, input 16 and 17 and output 18 and 19 clamps.

Input terminal 16 is connected to the first inputs of comparators 1 and 2, input terminal 17 is connected to the second and first inputs of comparators 2 and 3, respectively, the second inputs of comparator 1 and 3 are grounded, direct output of comparator 1 is connected to the first input of element I 6 and through the reset element 15 with the reset inputs of counters 10 and 11, the outputs of which are connected to

the inputs of the digital comparator 12, the output of which is connected to the first inputs of the elements 8 and 9, the outputs of which are connected to the output terminals 18 and 19, respectively, the inverse output of the comparator 1 is connected to the first inputs of the elements 4 and 5, the direct output of the comparator 2 is connected to burn the input element And 4, the output of which is connected to the second input of the element 8, the inverse output of the comparator 2 is connected to the first input of the element And 7, the output of which is, t; MF - the second input of the element And 9, r. my output of the comparator 3 is connected with the secondary input of the element 6, the output of which is connected to the input of the counter I, the inverse output of the comparator 3 is connected to the second inputs of the elements 7 and 5, the output of the latter is connected to the input counter 10, the third input element And 5 is connected to the output of the generator 13 pulses and the input of the frequency divider 14, the output of which is connected to the third input of the element And 6.

A device that implements the method of comparing the two amplitudes of two sinusoidal voltages, works as follows.

Comparators 1 and 3 of the input sinusoidal voltage) and V (t (Fig.26 and a) are converted into impedance voltages U and K of the type of a meander (Fig.2i and d), the fronts of which coincide with the moments of transition of the input voltages through the bullet value At the outputs of the comparator 2, a pulse voltage U of the type of a square wave (fng, 2g) is formed, the fronts of which coincide with the nearest moments of equality of the instantaneous values of the amplitudes of the input voltages

Of these three impulse voltages, the following impulse voltages are formed by means of elements 11, 4, 5, 6, and 7 (Figs. 2e, and

-. at the output of the element And 4 - the pulse voltage. in the second half-period of the compared voltages, the leading edge of which coincides with the instant of equality of the instantaneous amplitudes of the input voltages, and the decay of this pulse coincides with the instant of equality to zero of the instantaneous amplitude of the second of the compared voltages;

- at the output of the element And 5 the pulse voltage Uj in the second half-5I626I6S

the period of the compared voltage, the front and rear edge of which are determined by the moments of zero instantaneous values of the first and second io compared voltages;

- at the output of the element And 6 - the voltage Ug is similar to 1, but in the first period of the compared voltages;

- at the output of the element And 7 - the pulse voltage Ujr in the second half of the period of the compared stresses, the leading edge of which is determined by the moment when the instantaneous amplitude of the first of the compared stresses is equal to zero, and the momentum of the amplitude amplitudes of the amplitudes is comparable voltage

At the same time, tt as for one ich of the VUODs of the element I 6 also serves pulsed n. from the output of the frequency divider 14, then at the output of this element I 6 a burst of pulses is generated, i.e. a voltage pulse U filled with voltage pulses whose frequency f is much longer than the duration of this pulse Number of frequency pulsers of the divider 14 often i l oder in the voltage pulse fj at the input of the AND 6 element, the sketches are calculated 1 1,

The output of element II 5 also forms a burst of pulses U, but is filled with pulses from the output of the generator 13 pulses, the frequency of which is two times greater than the frequency of the pulses filling the pulse at the output of the element 6. As the number of these pulses is counted by counter 10, at the time point corresponding to the midpoint of the pulse at the output of the element I 5, the code of the counter 10 is compared with the code of the counter 11 and a short voltage pulse is generated at the output of the digital comparator 12 (voltage of FIG. 2k) "This short voltage pulse U served One of the inputs of elements And 8 and 9, to the other input of which pulses of voltages L 4 and U are output from the outputs of elements And A and 7, respectively.

If the amplitude of the input snus voltage applied to the device clamp 16 exceeds the value of the sinusoidal voltage applied to the device clamp 17, then the pulses at the outputs of the element And 7 and the digital computer

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Rotor 12 and a short voltage pulse U (j appears at the device clamp 19.) When the amplitude of the input voltages of the device is reversed, a short voltage pulse appears at the clamp 18 of the device (not shown).

At the beginning of the next period of the first of the compared voltages (at the moment of its transition through zero) from the pulse front from the output of the comparator 1, a short pulse is generated by the reset element 15, by which the counters 10 and 11 return to the initial state.

Claims (1)

Invention Formula A method for comparing the amplitudes of two sinusoidal voltages having the same frequency and out of phase, consisting in forming a control time interval, the beginning of which coincides with the first zero crossing of the first sinusoidal voltage during its transition from the negative (positive) region, and the end the first interval of time pi coincides with the first zero crossing of the second sinusoidal voltage upon its transition from a positive (negative) region, immediately following the first transition through a bullet the first sinusoidal voltage, form the first and second pulses, and the end of the first pulse coincides with the beginning of the second pulse and coincides with the moment of equality of the values of the first and second sinusoidal voltages after the second zero crossing of the first sinusoidal voltage, and also forms a short pulse, by position which, relative to the first and second pulses, judge the ratio of the amplitudes of the compared voltages, characterized in that, in order to increase speed, the beginning of the first pulse of At the time of the second zero crossing of the first sinusoidal voltage, the end of the second pulse is formed at the time of the second zero crossing of the second sinusoidal voltage, and a short pulse is formed at a time equal to the raspberry value of the control time interval from the second zero crossing of the first sinusoidal voltage .