SU476519A1 - Ac voltage meter - Google Patents

Description

This invention relates to the field of electrical measurement of the electronic technique.

Known ycTipoftCTBa measurements of the Average value of alternating voltage based on the conversion of voltage to frequency and the Integration of the obtained frequency during the transition, approximately the period of the frequency measured at | Prj, have a significant measurement error with changing frequency, from: rimated voltage.

The purpose of the invention is to eliminate the dependence of the measurement result on the frequency of the input signal. This is achieved by supplying the meter with two circuits — coincident, an assembly circuit, a memory device and two devices, 1A.A. and automatic frequency control, the first inputs of which are connected to the output of pho (the immersion device, the second napiBoro device, 1) The voltage driver is the frequency and “About the input of the two frequency ratio meter, and the output is to the control input of the slope of the voltage across the frequency converter, the frequency, the second input of the second device, A.v.t., the frequency is connected to the input of the circuits The assemblies of the first circuit are Sov1napi, and the output is connected to the input of the storage system (Royst, / and the other output of the voltage converter is frequency. It is connected through the second co-ownership scheme and the assembly circuit A. One 1GZ Inlet.B line delays, to the other input of which the memory output is connected, and output to the one of the inputs of the first matching circuit.

The drawing shows the functional circuit diagram of the, me | r.itel.

The voltage-frequency differential frequency sensor 1, the output of which has a frequency, is equal to the difference between the initial frequency and the frequency proportional to the input voltage, and the output 3 produces a frequency equal to the sum of two interconnected frequencies; shaper 4; schemes coincide 5 and 6; assembly scheme 7; Delay line 8 with an input 9 controlling the amount of delay 3 with a signal input 10; 1tel mix //; a storage device 12; the meter 13 is the ratio of two frequencies with the input 14, to which the value of the frequency of the delimine and the input 15, to which the value of the frequency of the delimiter is applied; self-tuning devices 16 and 17 frequencies with one input m) 18, 11 19 and others, inputs 1 20 and 21 respectively; the signal input 22 of the control unit and the input 23 of the control of the steepness-conversion of the converter /.

P1 meter works as follows.

When a control pulse is applied to the input 22, the coincidence circuit 5. And the meter 13 is transferred to the closed state, and all the others are in € T (the meter’s properties remain on. Circuit: crash; p, k 7, delay line 8 The circuit 6 forms a ring operating in the generation mode. In such a frequency is generated, equal to f where / 3 is the delay time. This frequency is fed to the input 21 of the frequency control device 17. The error voltage generated in the device 17 is fed through the memory 12 to control input 9 of delay line 8, changing delay time.With this, the frequency, which is emitted by the line zade-ral; K. and 8, is changed until it becomes equal to the frequency that influences the input 18 of the automatic frequency tuning device 17, i.e. is maintained equal to /., 3 Q or 7, where Q is the frequency of the oscillations of the measured voltage; T0 is the period of oscillations of the measured most .and. And. at this time the ring, forming a converter 1, the device 16 , supports the input 3 -converter / sum.marna frequency, a multiple of the frequency of the measured voltage. So k; k in differentialOm converter voltage-frequency total frequency / 1 is equal to (l + aAj, where / o is the initial frequency; l; - is measured. Voltage, a is a constant factor; and the difference frequency is equal to / r / o (1-al ;. then the total frequency / s at output 3, the selection is included in the converter / f.ilter, rav.vna / S 2/0, and the difference frequency / p output 2 is equal to / p 2 / o-ai, i.e., the frequency / s uniquely determines the slope of the conversion of the measured voltage to a different frequency. If supported, this provides the required. The change in the slope when the measured voltage is measured by the frequency of the measured voltage fp tiQax. If the value of x changes according to the law, this expression will be written in the form fp nQU ,, slnQt. The memory 12 is switched to the error voltage memory mode. At the same time, the delay time of the delay line 8 is maintained by 1 constant. At the same time, through the co-ownership scheme 5, the difference frequency (f) from the output 2 of the converter / enters the input of the assembly scheme 7 and then through it to the input 10 of the delay line 8. And the input of the mixer 11. To the other input of the mixer // - the same delay frequency arrives at the time. At the output of the mixer, a frequency is formed, equal to f 2nUQsm at 2nUQ 1, which is fed to input 14 of the frequency ratio 13, which npai the absence of a control and pulse is open. At the input of 15 measures: Ittel frequency ratio 13 receives the total frequency. As a result, a frequency ratio meter 13 is generated equal to the ratio of these frequencies. Thus, the number of and-multiple in N, corresponding to the average value of the measured voltage, is written in the form .. m, nU9-,,, L - - 2nmU, where t is a constant meter ratios From the last expression, it can be seen that the measurement result does not depend on the frequency. PREDIME T of the Invention An alternating current voltage meter containing a differential voltage converter is a frequency, the input of which is connected to the input of the former, the hold line, the input and output of which are connected to the input voltage. Mixer, and a two-frequency ratio meter, characterized in that OFI is equipped with two matching schemes, an assembly scheme, a minimum automatic tuning device and two frequency control devices, the first . inputs with are connected to the output of the form. world., the second input of the first automatic frequency control device. connected to one voltage output of the voltage converter - frequency and to the input of the two frequency ratio meter, and the output to the control input of the slope of the voltage converter - frequency, the second input of the second device Avtopodstroaki frequency is connected to the input of the assembly circuit and the output of the first combination circuit, and the output - to the input of the storage device, and the other output of the voltage converter -

The frequency is connected via a second coincidence circuit and a concatenation circuit to one of the inputs of the delay line, the other input of which is connected to the output of the sprinkler, and the output to one of the inputs of the first coincidence circuit.

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