SU651270A1 - Digital phase meter - Google Patents

Description

(54) DIGITAL PHASOMETER

which the front edges of the rectangular output pulses coming through the shaper to the forming unit

time interval, are formed with a lag in time from the moment ne

of the input signal through zero. The magnitude of this delay depends on the amplitude of the input signal, which leads to the measurement error of measuring the phase difference between the reference and phase-modulated signals and limiting the dynamic dianazone amplitude of the latter.

Usually this error reaches several degrees.

For example, if the limiting threshold of the limiting amplifier U is 0.1–10 V, the amplitude of the reference signal is 2V, and the amplitude of the input signal varies from 2 to 0, OO2 B, a measurement error occurs (fq 3.

The reduction of such an error with the abolition or increase in actuality of the input signal is limited by technical difficulty.

The purpose of the invention is to improve the measurement accuracy in a wide dynamic range of the amplitude of the phase-modulated signal.

The goal is achieved in that the digital phase meter, containing the sources of the reference and measurement signals, outputs which are connected to the inputs of the first and second limiter amplifiers, respectively, the time interval shaping unit, the first input of which through the first pulse shaper is connected to the output of the first limiting amplifier, the second input of the time interval shaping unit is connected to the output of the second pulse shaper, and the output of the time interval shaping unit is connected via a key the first input of the counter and the indicator device, as well as the pulse generator whose output is connected to the control input of the key, are entered. Generation interval i block, match element, counter trigger, reversible counter control unit, reversible counter, and the output of the generation interval through the generator the coincidence element and the trigger are connected to the first input of the control unit of the reversible counter and directly to the input of the second pulse shaper and the second

The control unit input is controlled by a rerouting counter, the output of an immersion generator is connected to the syncro terminal of the second amplification terminal, the first input of the allocation unit nnt ;. the generation shaft, the second input of the coincidence element and the third input of the reversing control unit 1SH1m counter, the fourth input of which is connected to the output of the first pulse generator, and the output of the control counter of the reversible counter are connected to the other inputs of the counter of the id indicator, the second output the amplifier limiter is connected to the second input of the block in the interval of the general-1In interval, in addition, the second amplifier-limiter is covered by positive feedback.

FIG. Figure 1 shows the electrical phase diagram of a digital phase meter; in fig. 2 is a block diagram of the allocation of the generation interval; in fig. 3 shows a positive electrical circuit of a positive feedback circuit with an input for synchronization from a pulse generator in FIG. 4 - timing diagrams that explain the operation of the phase meter.

The digital phase meter contains amplifier-limiter 1, a positive feedback circuit 2, a pulse generator 3, a block for allocating an interval to a gene. radio 4, coincidence element 5, counting trigger 6, reversing counter control unit 7, counter indicator device 9, limiting amplifier 1O, pulse forker 11 and 12, time interval forming unit 13 and key 14.

Measuring signal. arrives at amplifier 1, which, due to the introduction of the positive feedback circuit 2, operates in an oscillator-controlled oscillator mode 3. When the signal and l exceed the threshold, the limiting amplifier 1 enters into the nascent mode, and the generation stops. Thus, at the input signal values from - and to and at the output of the amplifier of the limiter 1, a burst of pulses occurs, and the transition point of the input signal through the zero value coincides with the middle of this burst.

Claims (1)

The generation interval allocation unit 4 generates a pulse whose duration is equal to the duration of a burst of pulses appearing when the signal crosses zero only on one iiO; iftj nosngin to another (for example, from o-triggered to positively). Matching Elemepe 5 selects a bundle of pulses corresponding to this type of control unit and the triper is divided. two. the number of pulses present in this packet, Imp-ups from the counting trigger 6; for those stupid through block 7 in reverse: the counter will carry out the information in chtgs.1sh. The time code from the moment the input signal goes through zero to the moment of the orpamnienim pulse from the generation block of the generation interval 4 (i.e., to the moment when the input signal reaches the value t Op.) Pulse generator 12 but the falling edge of this pulse generates a short pulse arriving in the block of the formative time interval 13, opens the key 14 to & ry. The result obtained in the counter of the device 9 shows the time interval corresponding to the phase shift between the signals, and The result of the phase measurement does not depend on the amplitude of the phase-modulated signal. The need for an irregularly reversible counter is explained by the fact that / there may be a case when the impulse from FORF1 11 arrives during an impulse at the input of the exponent of the interval 4 generator. pulses from the generator 3, from the moment of arrival of the pulse from the generator 11 to the end of the pulse at the input of the generation block of the generation interval 4. Such a case may occur if the phase difference between the reference and measuring The measured signal is close to a silo and the measuring signal has a small a 1plity. Such devices are powered by a reversible counter and are often found in the peripheral devices of digital computers, as well as in software devices of automation equipment. FIG. Figure 2 shows one of the possible options for constructing a block for allocating the 4s generation interval, a separate impulse, the duration of which is equal to the duration of the Pachyug Istrtsov, and the procedure 011us - at its input when the input signal passes through zero from one polarity to another. FIG. 3 one of the possible variants of the technical implementation of the positive feedback circuit of the feedback circuit. The GI for the amplifier has a synchronization input. If jKe for PIC arises the need to cut the signal, it is not necessary to insert an inverting element into this circuit. The operation of the proposed phase meter is illustrated in the time diagrams of FIG. 4, where on the plot 4a there is a representative sinusoidal phason-modulated signal and an output signal from the amplifier-limiter 1, the opaque. positive feedback on plot 46 — output pulses of a block of the selection interval of generation 4j on plot 4c — impulses at the output of the pulse shaper 12; on the plot 4g - infrared gulsa at the output of the pulse shaper 11; on the plot 4D - the pulses at the outputs of the counting trigger 6; on enure 4e - impulses at the output of key 14, Vvegshe. New elements and connections favorably distinguish the sensible Wide Phase Phase Meter from the prototype, since the component of the inaccuracy due to the change in the amplitude of the measuring signal has decreased. As a result, the total accuracy of the instrument is reduced and the range of the amplitude of the input signal is expanded, which expands the scope of application of this phase meter, and hence its technical efficiency. DETAILED DESCRIPTION OF THE INVENTION Phase number meter containing a source of reference and measuring signals whose outputs are connected to the inputs of the first and second amplifiers limit it, respectively, the first input of which is connected to the output of the first time pulse generator. The input of the time interval formation unit is connected to the output of the second pulse generator, and the output of the time interval section is connected to the first input An air detector device as well as a pulse generator, the output of which is connected to the control input terminal, differs in that.