SU363932A1 - DIGITAL PHASOMETER - Google Patents

Description

one

The invention relates to a digital measurement technology and can be used in remote control and automatic control systems.

The known digital phase meter with compensation for the influence of the frequency of the input signal on the measurement accuracy, based on the constant pulse frequency counting in a time interval proportional to the phase shift, and the conversion factor of these pulses changes in accordance with the value of the reference period, does not ensure sufficient measurement accuracy and speed.

The proposed phase meter allows for improved measurement accuracy and speed due to the fact that the difference code of the nominal period value and period deviation is determined by a counter, which subtracts the number of generator pulses for the current period of the reference signal from the double value of the nominal period. The phase shift code is determined by summing the obtained difference code a number of times equal to the number of generator pulses during the time error interval of the signals under study.

FIG. 1 shows a block diagram of the phase meter described; in fig. 2 shows the timing diagram of his work.

The phase meter contains a trigger /, the unit and zero inputs of which are connected respectively to the tires of the reference 2 and phase-shifted 3 signals, three delay lines 4, 5 and 6, pulse generator 7, gates 8, 9, ... 9p, 10, ... 10p , 11, ... Lp, adder 12, register 13, counter 14 and high-frequency pulse generator 15.

The phase shift of two signals, the frequency of which fluctuates relative to the average value, is determined by the expression m.

 -

GO-ATT - temporal mismatch of the studied signals B this step; 15To - the average value of the period;

LH - off signal period in

this tact.

If the period and the time error are filled with constant frequency pulses, 20 then the phase shift code will be equal to

That / + DG / or

„: / (7-о / - / АГ)

Since usually AG-sTo,

 t / (7o / - / DG)

(1) Tlf

The proposed phase meter measures the phase shift according to expression (1). For this, it is necessary to determine the difference code Go / -fAT. For this purpose, a counter 14 is used, which pulses the reference signal, delayed by delay line 4, to the 2Tof state. During the current period, the counter subtracts the number of 15 pulses coming from the generator. As a result, after the end of the period, the counter will be in the state

2T, (T, + AT) T, f-fAT.

The pulse of the reference signal counter code through the valves 10 ... 10p is transferred to the register 13 with a shift of the order of the number of bits

2 In Go /

P

In 2

The frequency of the generator must be such that the integer value of the number d is ensured.

In the presence of the difference code of the average period and the current period gap, the adder 12 calculates the phase shift code. The valve 8 during the time error interval is opened with a high potential of the trigger /. Therefore, the geyerator's pulses that fill this interval summarize the difference code in the adder 12. The phase shift code is output to the device by a pulse generated by the driver 7. This same impulse, delayed by the delay line 5, sets the adder 12 to the zero state.

The operation of the proposed phase meter is illustrated by the time diagrams of FIG. 2, where plots 1 and 2 show the sequence of supporting and phase-manipulated signals, plot 3 shows the voltage at the single output of the trigger /, and plot 4, the pulses of the high-frequency generator 15, and plots 5 and 6 show the pulses at the output of the delay line 4 and valve 8.

Subject invention

A digital phase meter containing a counter, a register, a high-frequency pulse generator, a trigger, valves, characterized in that, in order to increase measurement accuracy and speed, the inputs of the adder are connected to the outputs of the register connected to the high-frequency generator and to the outputs via gates valve, another input connected to the trigger, and the output to the code transfer valves from the register to the adder, with the support of the reference signal connected to the input of the register setting to its initial state schnne governmental and setting an initial counter state and a valve transmitting a code from the counter into the register through the delay Lynn and input ustaliOBKH initial state of the adder and dispensing valves measurement result of the adder connected to respective pulse shaper 1 ° through the delay line directly.

MIL