SU890263A2 - Phase difference meter - Google Patents

Description

one

This invention relates to a radio metering technique and can be used in phase metering.

According to the main author. St. No. 516000, a phase difference meter is known comprising a series-connected switch, a linear phase detector, a selective switching frequency amplifier, a synchronous detector, a registering device, as well as a control trigger, a discriminator, two series-connected single-oscillators, one of which is connected by its input to a control trigger , and a logical three-input element I, which is connected to the outputs of one-vibrators by two inputs, and the third by a discriminator, while the phase detector is connected to the source Input signals directly and through the switch, which, in turn, is connected to the control trigger and the synchronous detector 1.

A disadvantage of the known phase difference meter is a decrease in the measurement accuracy when exposed to destabilizing factors.

(aging of elements, temperature fluctuations, voltage, moisture).

The impact of these factors is caused by a change in the parameters of the blocks entering the measuring path and determining its metro characteristics. Thus, a change in the parameters of the selective switching frequency amplifier, which causes the detuning of the resonant frequency of the amplifier relative to the switching frequency of the control trigger, not only has a direct effect — reducing the gain of the resonant amplifier, but also affects the transmission coefficient. (This detector is a function of the cosine of the phase shift angle between the input voltage of the detector and the reference voltage. The result is a low measurement accuracy.

The aim of the invention is to improve the accuracy of measuring the phase difference.

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Claims (3)

The goal is achieved by the fact that a phase difference meter comprising a switch, a linear phase detector, a selective switching frequency amplifier, a synchrometer detector; registrar module, control trigger, discriminator, two coeAiiiieunbix mono-vibrators, three-input logical element AND, and the phase detector is connected to the input sources directly and through a switch, which is connected to the control device and the sensor and the control panel via the two inputs to the control device and the control unit, and the sensor connects it to the components of the component and the control unit of the sensor and the control unit, which connects the two components to the control device and the control unit and the control unit of the sensor and two devices connected to the control unit and the control unit and the control unit of the sensor and the control unit. A switching switching amplifier and a registering device, one 13 single-oscillators are connected by two connectors with a synchronous detector with a switch and a control trigger, the Loprg A track element Both via two inputs is connected with one-vibration outputs, and a tertiary is connected with a discriminator, a phase discriminator is introduced, the output of which is connected to the control input of an oddovibrator connected by another input to a synchronous detector, switch and junction module DIM trigger, and a discriminator input connector. the output of the selective amplifier 15 control trigger. In the drawing there is a futacion diagram of the proposed phase difference meter. The device contains a shared browser, a javascript, and a javascript and phase discriminator I. The device works with the north-west side. in a way. The signals under study are alternately connected to a linear frequency of 5yt. 2. At the same time, the signals Uj and Ui are connected to the phase detector 2 in the switching cycle; the signal U is fed to the detector at a different time. In the result, the switch.NP-; On the output of the phase detector 2, a rectangular voltage is formed with a switching frequency and an arcing proportional to the measured phase difference. Voter 1Y amplifier 3 selects and amplifies the first harmonic of this voltage. From the output of the selective amplifier 3, the signal arrives at the synchronous detector 4, the constant component of the output voltage of which is proportional to the phase difference of the compared signals. The generation of pulses for T1 relaxation by the switch 1 and the synchronous detector 4 is carried out as follows. The pulses from the output of the discriminator 7 are fed to the logical three-input element And 8, open at the initial moment of time through two other inputs. This allows the first of the pulses to pass through the open logical element AND 8 and to flip the trigger 6 into the opposite state. The voltage drop from one of the arms of the trigger 6 overturns into an unstable state for a time T controlled one-shot 10, and the further passage of pulses through the AND 8 element stops. After a time, the controlled one-shot 10 returns to its original state and overturns the one-shot time 9 to the unstable state. After the return of the single-slot 9, returns to the inputs of the And 8 element, the opening voltage is applied again to the inputs of the E 8. The next pulse from the discriminator 7 is fed to the counting input of the trigger 6 and tilts it to its original state. The controlled one-shot 10 is again transferred to an unstable state, and the whole process is repeated from the beginning. Since the trigger 6 is triggered by pulses corresponding to the moment of transition of one of the inputs 1x signals through zero, the period of the output pulses is a multiple of the frequency of the studied signals. In this case, the switching frequency is determined by the delay time T and r of the single vibrators and is constant over the entire range of the signals under study, if the voltage is equal to zero at the control input of the controlled single vibrator 10. At nominal values of the parameters of the meter blocks, the resonant frequency of the co-selective amplifier is equal 3 of the switching frequency O of the developed controlled trigger 6, the output voltage of the phase discriminator And is thus zero and does not affect the time TI of the controlled delay one ibrator 10. However, if as a result of a change in the parameters of the selective amplifier 3 or any of the single vibrators 9 or 10, the resonance frequency w of the amplifier 3 and the switching frequency J2 defined by the resulting delay t TI +12 single vibrators 9 and 10 mismatch, then at the output of the phase discriminator 11 voltage appears. The magnitude of this voltage is determined by the absolute value of the detuning (WQ - fi), and the sign is determined by the direction of the detuning (up or down relative to co o). The output voltage of the phase discriminator 11, acting through the regulating input of the controlled one-shot 10, changes the delay time TI, so that the resulting delay t TI + Tz becomes equal to the inverse of the true value of the resonant frequency tjQ of the amplifier 3. Thus, as a result of the action of the self-tuning circuit formed by the newly introduced phase discriminator, the influence of destabilizing factors is significantly weakened. 58 thereby stabilizes the resulting sensitivity of the phase difference meter, which ultimately leads to an increase in measurement accuracy while retaining all the advantages of the known device. Claims for the invention [Izmetov] phase difference according to copyright certificate No. 516000, differing. In order to improve accuracy. A phase discriminator has been entered into it, the output of which is connected to the control input of a single vibrator, connected by another input to a synchronous detector, a switch and a control trigger, and the inputs of a discriminator connected to the output of a selective amplifier and control trigger. Sources of information taken into account prm examination 1. USSR author's certificate M 516000, cl. G 01 I 25/00, 1974.