SU1307379A1 - Phase comparator - Google Patents

Abstract

The invention relates to a measurement technique, in particular to a technique for comparing electrical signals in phase. The phase comparator contains a driver 1, RS-flip-flops 2.4, elements AND 3.5, element OR 6. The introduction of new electrical connections between functional elements increases the reliability and simplifies the design of the phase comparator. 2 Il. (L of fig. 7

Description

one

The invention relates to electrical measuring equipment, namely, to a technique for comparing the electrical quantities (signals) in phase, and can be used in information-measuring devices and in systems of automated monitoring and control, in particular, AC electric generators.

The purpose of the invention is to increase the reliability and simplify the comparator.

Figure 1 shows the functional diagram of the phase comparator in figure 2 - time diagrams of his work.

The phase comparator contains shaper 1, the first RS-flip-flop 2, ne is the AND 3 element, the second RS-flip-flop the second is the AND 5 element and the OR 6 element.

The first output of the driver 1 is connected to the S-input of the first RS-flip-flop 2, the first input of the first And 3 element and the first R-input of the second RS-flip-flop.4.

The second output of the imaging unit 1 is connected to the S-input of the second RS-flip-flop 4, the first input of the second element 5 and the first R-input of the first RS-flip-flop 2.

The second R-inputs of the first and second RS-triggergv 2 and 4 are connected to the terminal of the initial installation.

The second inputs of the first 3 and second 5 elements And are connected respectively to the direct outputs of the first and second RS-flip-flops 2 and 4, and the outputs - to the inputs of the element OR 6. The shaper converts the input

alternating voltage in two order;

short square-wave pulses, one of which is formed at the moments of transition of negative half-waves to positive (positive zero-transition) and the other to

-

moments of transition of positive half-waves to negative (negative zero-transition).

In the phase comparator, there are also presetting circuits for the second R-inputs of the RS flip-flops 2 and 4 to the zero state at the direct outputs.

Phase comparator. Works as follows.

After supplying power to the phase comparator, pulses in the preset circuits RS-flip-flops 2 and 4 are set

ten

15

-,

20

thirty

but-;

45

zeroing in on the direct outputs.

For example, consider the arrival at the input of a phase voltage comparator of the form indicated in Fig. 2a (corresponds to point A in Fig. 1).

Shaper 1 converts it into two sequences of pulses, each of which is formed from either positive or negative zero transitions (Fig. 26 corresponds to point B in Fig. 1, Fig. 2c corresponds to point B in Fig. 1).

The first pulse of the sequence from the first output of the driver 1 (FIG. 2b) switches the RS-flip-flop 2

at the direct output (fig.2g) and l

in 1

tl

and confirms U at the direct output of RS flip-flop 4 (fig.2d). At the output of the element And 3 this pulse does not pass (Fig. 2e corresponds to point D in FIG. 1;), since the element And 3 is closed O from the output of the RS flip-flop 2 (necessary.

It is possible to take into account that switching of RS-flip-flops occurs with a certain time delay and the duration of pulses of driver 1 is less than the delay of switching of RS-flip-flops). At the output of the phase comparator pulse signal is missing (Fig.2i corresponds to the point And in Fig.1).

The first pulse of the sequence from the second output of the imager 1 (figv) switches the RS-flip-flop 4

35 in 1 at the direct output (figd)

and the RS flip-flop 2 in O at the direct output (FIG. 2d). At the output of the element And 5 this pulse does not pass (fig.2zh corresponds to the point W in figure 1), since the element And 5 is closed O from the output of the RS flip-flop 4. At the output of the device, a pulse signal is still missing (fig.2i) . }

When a second pulse is received from the first output and the second pulse from the second output of the imaging device 1, the operation of the device is similar to that described.

When the third pulse is received from the first output of the 1-body 1-body 1, the RS-flip-flop 2 switches back to 1, and the RS-flip-flop 4 to O. input voltage). The state of the RS flip-flops 2 and 4 does not change through the element And 3. This

40:

50

55

the impulse has already passed, since at the first output of the And 3 element there is an enabling signal from the output of the RS flip-flop 2.

At the output of the phase comparator, a pulse signal (Fig. 2i) fixes a phase reversal of the input voltage by 180 °.

With the arrival of the third Tio pulse count from the second output, the fifth pulse from the first output, the fourth pulse from the second output, the sixth pulse from the first output of the imaging unit 1, the operation of the device is similar to that described from the initial state.

When the fifth pulse arrives from the second output of the imager 1, the RS flip-flop 4 is switched to 1 to the direct output.

But the next two pulses of the second output (the sixth and seventh) come from the second output of the imaging device 1, which corresponds to a twofold reversal of the phase of the input signal. Both of them will pass through element 5, since at its second output there is a permissive signal from the output of the RS flip-flop 4. At the output of the phase comparator, signals are generated that fix the pephasic comparator containing the driver, the input of which connects to the input terminal of the comparator, two elements And, two RS-flip-flops and an OR element, the output of which is connected to the output terminal of the comparator, and the inputs to the turns of the AND elements are connected, respectively, to the outputs of the driver, and the outputs to the inputs of the OR element, while the second input of the first element AND is connected to pr we The output of the first RS flip-flop, which is different in that, in order to improve reliability and simplify the battery, the direct output of the second RS-trgr is connected to the second input of the second element I, the S input of the first RS-t is connected to the first R-input of the second RS-flip-flop and the first output of the user, the second output of which is connected to the first R-input of the first

phase reversals of the input signal.

The proposed phase comparator 30 RS-flip-flop and S-input of the second RS- (in comparison with the known ones) has a flip-flop, and the second R-inputs of the first increased reliability of the function and second RS-flip-flops are connected to

vani provided by exception

P

v / H / H / H / UCHA / V

1 П П П П П

p7 p5

P1P1.

Editor A.Revin

Compiled by M. Katanova Tehred L. Serdyukova Proofreader M. Demchik

Order 1628/45

Circulation 731 Subscription

VNIIPI USSR State Committee for Inventions and Discoveries 4/5, Moscow, Zh-35, Raushsk nab. 113035

Production and printing company, f. Uzhgorod, ul..Proektna, 4

false comparator sravataniyah due to the arbitrary initial installation of triggers and has a simpler functional composition.

Claims (1)

Invention Formula A phase comparator containing a driver, whose input is connected to the input terminal of the comparator, two AND elements, two RS-flip-flops and an OR element, the output of which is connected to the comparator output terminal, and the first elements of the AND elements are connected to the driver's outputs, and the outputs are from the inputs of the OR element, while the second input of the first element AND is connected to the direct output of the first RS flip-flop, characterized in that, in order to increase reliability and simplify the comparator, the direct output of the second RS flip-flop is connected to the second input of the second of gate AND, S-input of the first RS-flip-flop connected to the first R-input of the second RS-flip-flop and a first output of the second output of which is connected to the first input of the first R- comparator reset terminal. p7 p5 pz p ng 2