SU1092431A1 - Digital phase meter - Google Patents

Abstract

A DIGITAL PHASOMETER containing a KOMNfyTaTop, a reference frequency generator, an electronic switch, a frequency multiplier, an adder, a digital divider and a recorder, and two channels connected to the electronic switch and switch, each of which includes a linear amplifier whose input is combined with a phase meter input and a linear output the amplifier is connected to the input of the latch, the outputs of which are connected to the inputs of the block of the moments of signal transition through the maximum value and the inputs of the generator of shock excitation, and the output of the generator of the impact The main excitation is connected to one of the inputs of the block for selecting the moments of signal transition through the maximum value, the switch outputs are connected to the second inputs of both latch-. for the purpose of improving the measurement accuracy, two triggers, two additional electronic switches and two digital logometers are inserted into each channel, each channel having two series-connected circuits The trigger, an additional electronic key and a digital logometer are connected respectively to two (L level lock outputs, the second inputs of the additional electronic keys are connected via a frequency multiplier to the reference frequency generator, the second digital inputs Ogometers - with the output of the main electronic key, and the outputs of the digital logometers are connected to the common inputs of the adder. 4 WITH

Description

1 The invention relates to a phase-measuring technique and can be used to measure the phase angle between two electric waves. A phase meter is known that uses to measure the signal transition point through the maximum of the investigated signals, containing a reference frequency generator, a frequency multiplier, an electronic key and a recorder, as well as two channels associated with the electronic key, each of which includes a signal transducer zero values and a scheme for separating the moments of signal transition through maximum values of Cl3. . However, this device does not have a sufficiently high accuracy due to the influence of nonlinear distortions of input signals; therefore, the measurement results contain systematic error. The closest to the present invention is a method for measuring the phase angle between two harmonic signals and a device for carrying it out, comprising a switch, a reference frequency generator, an electronic key, a frequency multiplier, an adder, a digital divider, a recorder, and two channels connected to the electronic key of which is provided with a level lock, a generator of shock excitation and a linear amplifier, the input of which is combined with the input of the device, and the output of the linear amplifier is connected to the input of the level lock, in the strokes of which are connected to the inputs of the circuit for switching the signal through the maximum value and the input of the shock excitation generator; and the output of the generator for shock driving is connected to one of the inputs of the block for the switching moment of the signal through the maximum value of the switch outputs, and The tronna key is connected to the recorder via an adder and a digital divider L 2. The disadvantage of the device is low accuracy, due to the high level of random error. The purpose of the invention is to improve the measurement accuracy due to a significant reduction in the random component of the measurement error. This goal is achieved in that a digital phase meter containing a switch, a reference frequency generator, an electronic key, a frequency multiplier, an adder, a digital divider and a recorder, and two channels connected to the electronic key and the switch, each of which includes a linear amplifier whose input is combined the phase meter input, and the output of the linear amplifier is connected to the input of the latch, the outputs of which are connected to the inputs of the block for selecting the moments of signal transition through the maximum value and the inputs of the shock generator About the excitation, and the output of the percussion excitation generator is connected to one of the inputs of the block where the signal transition times the maximum value, the switch outputs are connected to the second inputs of both latches, two triggers, two additional electronic switches and two digital logometers are inserted into each channel in each channel, two series-connected circuits, consisting of a trigger, an additional electronic key and a digital logometer, are connected respectively to two outputs of the latch, with the second inputs Additional electronic switches are connected via a frequency multiplier with a reference frequency generator, the second inputs of digital logometers are connected to the output of the main electronic key, and the outputs of digital logometers are connected to the inputs of the adder. The drawing shows a functional diagram of the device. The device consists of two channels, each of which has a linear amplifier 1 (2) whose inputs are connected to the inputs of a digital phase meter, the output of the linear amplifier 1 (2) is loaded to the input of clamps 3 and 4 levels and switch 5 connected to the inputs latches. Two outputs of latches 3 and 4 levels are connected with two inputs of shock excitation generators 6 and 7, with two inputs of blocks 8 and 9 of the moment of signal transition through the maximum value and with outputs of triggers 10 and 11 (12 and 13). The device also contains electronic keys 14-18. The output of the generator 6 (7) is connected to the input of blocks 8 and 9, and the outputs of the triggers 10 and 11 (12 and 13) to the inputs of the electronic switches 14 and 15 (17 and 18), respectively. The electronic keys 14-18 are coupled to the generator 19 through a frequency multiplier 20. The outputs of the electronic switches 14 and 15 (17 and 18) are connected to the input of the divisible register of the corresponding digital logometer 21 and 22 (23 and 24). The outputs of digital logometers 21 and 22 (23 and 24) of both channels are connected to the inputs of the adder 25, the output of each of which is connected to the recorder 27 via a digital divider 26, the inputs of the phase shift electronic key 16 are connected to the outputs of blocks 8 and 9, and the output of the electronic switch 16 is connected to the input of the registers of the dividers of digital logometers 21-23. The device works as follows. The harmonic oscillations arrive at both inputs of the phase meter and are amplified with the help of linear amplifiers 1 and 2 until the selected fixed division is the same for both channels. When the Reset button is pressed, all counting nodes of the phase meter are brought to the initial operating state. The amplified harmonic oscillations arrive at the input of the ZIL clamps of the levels, which set the constant voltage levels by n / 2 identical pairwise levels in the positive and negative voltage areas and generate a short pulse at the moments when the input signal crosses the selected voltage level and. . The switch 5 selects one of the levels U, - and at the end of the measurement at the selected level U- switches the latches to another voltage level, the same for both latches. Thus, the selection of the voltage levels and the output latches of the latches occurs. 3 and 4 are fed to the inputs of blocks 8 and 9 and to the inputs of generators 6 and 7, which are triggered from the first pulse of the corresponding latch and 314 stop generating on the second latch pulse. Both oscillators 6 and 7 generate a sequence of high frequency pulses synchronous with respect to the first (triggering) pulse of the corresponding latch of levels. Synchronization of the filling pulses relative to the trigger ensures the accuracy of dividing the allocated time interval into two by subtracting, since there are no random fluctuations of the pulse corresponding to the middle of the allocated time interval and the maximum of the input signal in the interval Go-T |, where T ((is the follow frequency of the input frequency. At the outputs of latches 3 and 4, short pulses appear at the moments of transition of input voltages through the maximum value. The output pulses of latches 3 and 4 through triggers 10-13 open ktron keys 14, 15 17, 18. The pulses of the generator 19 through the multiplier 20 and the electronic keys 14, 15, 17 and 18 are fed to the input of the divider registers of digital logometers 21-24, and through the multiplier 20 and the key 16 - to the inputs of the dividend registers of digital logometers 21-24. The output pulse of the circuits closes the keys 16, 17, 18, 14, 15 and blocks the frequency multiplier 20. After the switch 5 selects all n predetermined voltage levels, the quotient from the division factor of 360 is received at the output digital logometers for each i-ro level goes to the input of the adder N-J t 1 h, cmf frequency input signals; the ratio of the frequencies at the inputs of the divider and the splittable logometers; a time interval proportional to the phase shift of the input signals; the period of the input frequency, measured at the i-th level, the reference frequency. From the output of the frequency divider 26, where the results are averaged, obtained at the adder over the number of levels, the number of pulses equal to the value of the measured phase shift is sent to the recorder input

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The use of the proposed digital phase meter allows reducing the resulting measurement error, increasing the measurement accuracy by more than an order of magnitude.

Claims (1)

A DIGITAL PHASOMETER containing a switch, a reference frequency generator, an electronic key, a frequency multiplier, an adder, a digital divider and a recorder, and two channels connected to the electronic key and the switch, each of which includes a linear amplifier, the input of which is combined with the input of the phase meter _? and the output of the linear amplifier is connected to the input of the level lock, the outputs of which are connected to the inputs of the block allocating the moments of transition of signals through the maximum value and the inputs of the shock generator, and the output of the generator of shock excitation is connected to one of the inputs of the block of extracting moments of the transition of signals through the maximum value, the outputs of the switch connected to the second inputs of both fix-. tori of levels, it is important that, in order to increase the measurement accuracy, two triggers, two additional electronic keys and two digital logometers are introduced into each channel, while in each channel there are two series-connected circuits consisting of a trigger, an additional electronic key and a digital logometer are connected respectively to two outputs of the level lock, and the second inputs of the additional electronic keys are connected via a frequency multiplier to a reference frequency generator, the second inputs of a digital logometer - with the output of the electronic key, and outputs the digital ratiometer connected to inputs of the adder.