SU1582151A1 - Phase meter of infra-low frequencies - Google Patents

Abstract

The invention relates to electrical measuring technique and can be used when calibrating means of measuring phase shift in the infra-low frequency range. The purpose of the invention is to improve the accuracy of phase shift measurements. The device contains an automatic switch 1, amplifier-limiter 2, switch 3, control trigger 4, reversing counter 5, high-frequency generator 6, inverter 7, reversing counter 8, trigger 9, one-shot 10 and 11, inverter 12, element OR 13, synchronization node 14 and one-shot 15 and 16. The goal is achieved by dividing and separating the clock frequency and switching frequency of the switch, thereby increasing the clock frequency. 2 Il.

Description

The invention relates to electrical engineering and can be used when checking the means of reproducing a unit of the angle of the phase shift in the infra-low frequency range.

The purpose of the invention is to improve the accuracy of phase shift measurements.

In FIG. 1 shows a block diagram of a phase meter; in FIG. 2 - stress diagrams at various points of the block diagram.

The infra-low frequency phasometer contains an automatic switch 1, an amplifier-limiter 2, a switch 3, a control trigger 4, a key 5, a high-frequency generator 6, an inverter 7, a reversible counter 8, a trigger 9, one-shots 10 and 11, an inverter 12, an OR element 13, synchronization unit 14 and single vibrators 15 and 16 “Automatic switch 1 is connected to the input of the amplifier-limiter 2o. The control input of the automatic switch 1 is connected via switch 3 to the direct output of the control trigger 4 and to one of the key inputs 5. Another key input 5 is connected to the output of the high-frequency generator 6, and the output is connected to the input of the reversible counter 8 °. Trigger 9 is connected by its inverse output to the control input of the one-shot 11, which is connected to the output of the amplifier-limiter 2 and through the inverter 12 to the input of the one-shot 10. Simultaneously the one-shot 11 is connected with its output to one of the inputs of the OR 13. The second input, the OR-13 is connected to the output of the one-shot 10, and the output is connected to one of the inputs of the synchronization unit 14. The second input node 14 of the synchronization is connected through a single vibrator 15 with the inverse output of the control trigger 4. With its separate inputs, the control trigger 4 is connected to the output of the node 14 synchronization, and a direct output through the one-shot 16 to the input of the inverter 7. The output of the inverter 7 is connected to the counting input of the trigger 9 , and the input with the third input of the node 14 synchronization.

The phasometer infra-low frequencies operates as follows.

. The input signals are U _BX , and U _{6x g} (Fig. 2a, continuous lines correspond to U _6X p dot-line lines - U ax. T are fed to the inputs of automatic switch 1. Depending on its position, the output of switch 1, i.e., to the input limiter amplifier 1, transmit a signal ^and _Bx <or Ubx; 2 · In the initial state, the automatic switch 1 is in a position in which the signal U _{BX о} is transmitted to its output (Fig. 2b) and held in this position by the low potential of trigger 4, being in state 0, in addition, with the same low potential, it holds It is closed.

Trigger 9 is also, like trigger 4, at position 0 (FIG. 2c). In addition, the low potential trigger 9 is kept closed at the output of the single vibrator 10, and the single vibrator 11 is open (Fig. 2d).

Thus, in the initial state, the signal U _{Byi is} supplied to the amplifier-limiter 2 from the output of the automatic switch 1, amplified, limited in level (Fig. 2c), and then fed directly to the one-shot 11 and through the inverter 12 to the one-shot 10.

The single vibrators 10 and 11 form short pulses from their incoming signals at their trailing edges. Moreover, at the output of the one-shot 11 short pulses are formed corresponding to the moments of transition of the input signals through zero in the negative direction, and at the output of the one-shot 10 to the moments of the transition through zero of the same signals in the positive direction. Since in the initial state the one-shot 11 is open, and the one-shot 10 is closed, then at the output of the OR 13 element there are short pulses corresponding to the moments of the transition through zero by the signal U _Bx in the negative direction (Fig. 2d; the first pulse is indicated by a continuous line). The arrival of these pulses to the synchronization unit 14 does not change the O ”position of the control trigger 4. Only after the Start command has been sent (Fig.2e), the first short pulse from the output of the OR element 13 to the synchronization node 14 is set to position 1. The pulse corresponds to a high trigger potential 4 (Fig. 2i, k), opens the key 5 and the quantizing pulses f _K0 (Fig. 2m) begin to come from the generator 6 through the key 5 to the input of the counter 8. In addition, the pulse (Fig.2i) is supplied from the direct output trigger 4 to the control input switch A 1, setting it in a position in which its transmitted output signal U _{B 2} (FIG. 26).

At the moment of changing the high potential at the inverted output of the trigger 4 to a low one-shot 15 produces a short pulse (Fig. 2L), which is fed to the synchronization unit 14, preparing the trigger 4 to transfer to 0. At the moment the signal goes through zero in the negative direction, the one-shot 11 produces a short pulse (Fig. 2d, dashed line), which through the OR element 13 and the synchronization unit 14 (Fig. 2o) puts the control trigger 4 in position 0. In this case, the automatic switch 1 is set to the position at which stroke limiter amplifier U _ftx1 signal is supplied, a switch 5 is locked, that stops delivery of pulses to the input of the counter 8.

The result of quantizing pulse counting by counter 8 (Fig. 2h) for a time equal to a phase shift of 2 C, between negative transitions of the same name through the zero level of signals U _8it1 and U _{βΧ 2} , is determined by the number

N if, = ^f q *

This ends the first cycle of measuring the angle of the phase shift for negative transitions through zero input signals.

At the moment the control trigger 4 is flipped to position 0, a short pulse is generated at the output of the one-shot 16 (Fig. 2l), which enters the synchronization unit 14 in order to start the second measurement cycle □ In addition, this short pulse through the inverter 7 (Fig. 2p) changes its position flip-flop 9, setting it to 1 (see _for figo2s, t), which on its low potential inverse output bars by input monostable multivibrator 11, and high output of the switch 7 connects to the input of a reversing schetch'i- ka 8 and opens on an output monostable SO

The first short pulse (Fig. 2e), formed at the moment of transition

ΙΟ

1582151 6 cuts the zero level in the positive direction of the signal ϋ _βχ ,, _topples control trigger 4 again to position 1 (Fig. 2i). Next, the pulse corresponding to the high potential at the direct output of the trigger 4, opens the key 5 and the quantizing pulses begin to arrive at the input of the counter 8 (Fig. 2m). In addition, the specified pulse goes to the control input of the switch 1, setting it to the position at which limiting amplifier signal U. ,,. The pulse (Fig. 2L), generated by a single-shot 15 at the moment the high potential changes to low at the inverted output of trigger 4, enters the synchronization unit 14 and prepares the control trigger 4 for resetting to position 0 without changing its state. Only at the moment of passing through zero in the positive direction of the signal U _gx , a short pulse is generated at the output of the one-shot 10 (Fig. 2b, d), which is transmitted through the OR element 13 to the synchronization unit 14 and resets trigger 4 to state 0. This is the second measurement cycle ends: according to the signal of the synchronization unit 14 (FIG. 2y), <pin 5 is locked, the counter 8 stops working on the summation of the second packet of quantizing pulses, c. the initial state returns switch 1, switch 7, · as well as triggers 4 and 9.

(

The result of the summation of the second packet of quantizing pulses over a time equal to the phase shift between the positive transitions of the same name through the zero level of the measured _6U . _? is determined

-η • L

II

the second packet is quantum calculated for measurements in the form of signals U _ix , and the number

CT - -R

Q 2 * k S

The sum of the first fading pulses, the time of two cycles of the number

Nq »= N + is proportional to the measured angle of the phase shift, is fixed on the display panel of the lamp, or, if necessary, is entered by LIKI and further information.

The switch for calibrating the phase meter when changing hours in a computer for the purpose of storing

Toty of the measured signals or when working with a computer to determine the value of N _r , which is part of the algorithm (/ = - ^N - ^ -. ^N ^ 180 -10, where Ν _τ is the number of pulses arriving at the counter for a time equal to the period T of the input signal;

- measured phase shift; η is the number that is selected depending on the required measurement accuracy, I

Compared with the pre-prototype pre-jjaraeMbifi phase meter, it is possible to increase the order of magnitude due to synchronization and input signals

Н reduction of the switching frequency with a constant value of the frequency signal of the danthanum.

Claims (1)

Claim Infra-low frequency phasometer containing automatic switching of ^r, spruce, serially connected Amplifier-limiter and one-shot, pulse generator and Synchronization unit, characterized in that, in order to increase the accuracy, two inverts of accuracy are introduced into it (up to 0.02 °) for the switching torus, three one-shots, a control trigger, a counting trigger, a key, an output counter, an OR element and a switch, while the output of the 5 switch through a series-connected amplifier limiter, the first inverter and the second one-shot connected to the input of the ed element OR, the second input of which is connected to the output of the first one-shot, and the output is connected to the first input of the synchronization node, the second and third inputs of which are connected to the outputs of the third and third the fourth one-shot, the fourth input - with the Start signal bus, the first output through the control trigger connected in series, the 2Q odd one-shot and the second inverter - with the input counting trigger, and the second output through the control trigger with the input of the third one-shot, the output of the pulse generator, 25 is connected to the first input of the key, the output of which is connected to the counter input, the second key input is connected to the direct output of the control trigger and the switch input, the second input is 30 it is connected to the zero bus, and the output to the control input of the automatic switch, while the inverse and direct outputs of the counting trigger are connected respectively 35 with control inputs of the first and second single vibrators. FIG. 2