SU779898A1 - Non-linear distortion calibrator - Google Patents

Description

(54) CALIBRATOR OF NONLINEAR DISTORTIONS

one

The invention relates to the field of radio measurements and can be used in the development and creation of calibration equipment for selective voltmeters, harmonic analyzers, 5 nonlinear distortion meters, to assess the effect of the shape of the curve on the measuring transducers and voltmeters of alternating voltages, etc. .ten

A device for obtaining a signal calibrated by a non-linear distortion factor, consisting of two sources — first and second harmonics, an adder, a switch, a 5. generator of a linear variable variable voltage, and an oscillographic indicator fl.

The error of setting the nonlinear distortion coefficient of this technical solution is determined by the error of the visual installation of voltage extrema on the oscillographic indicator, frequency error and resolution of the oscillographic indicator, and the stability of the linear-step voltage generator;. The preparation time of the device for operation is determined by the time in turn

Noise level manual installation of linear-step voltage generators, first and second harmonics on an oscillographic indicator.

The closest technical solution is a device for obtaining a signal calibrated by a nonlinear distortion factor, containing a first and higher (e.g., second) harmonics generator, a differential comparator, an exemplary voltage divider, and an adder 2j.

The disadvantages of the known device are the error of the established nonlinear distortion coefficient caused by the ability of the differential comparator to be resolved and the different time drift of the two channels of the differential comparator; the need to calibrate the differential comparator against a reference signal to eliminate drift.

The aim of the invention is to improve the accuracy by periodically eliminating the differences in the time drift of the two channels of the differential comparator.

Claims (2)

The goal is achieved in that the nonlinear distortion calibrator containing the first harmonic generator is connected via an adder to one h input of a differential comparator, the second input of which is connected to a high harmonic generator directly and through an exemplary voltage divider connected to the second input of the adder, and the output differential a special comparator connected with a control input of the first harmonic generator, two synchronous triggered contact groups, a sampling, storage and information output unit, are entered, open The contact and control unit, the switching clocks of synchronously actuated contact groups are connected to the inputs of the differential comparator, the first contact and the opening contact of the second contact group are connected to the output of the higher harmonics generator, the first contact and the second contact of the second contact group are connected to the output of the adder, the output of the block for sampling, storing and issuing information is connected with the control input of the first harmonic generator, and the input through the break contact is connected to the output House differential comparator, the control unit is coupled to the sampling unit, and storing information vzdachi, break contact and synchronously erabatyvayuschimi contact groups. The block diagram of the calibrator is shown in the drawing. The nonlinear distortion calibrator comprises a first harmonic generator 1, a second harmonic generator 2, a sampling, storage and output unit 3. information, opening contact 4, differential comparator 5, control block b, synchronously triggered contact groups 7, adder 8, exemplary voltage divider 9 The output signal is removed from the output. The calibrator operates as follows. In the fixation mode, the effective values of the output voltages of the high harmonic generator 2 and the adder 8 are kept equal. At the same time, the output 10 of the non-linear distortion calibrator establishes a voltage with a calibrated value of the non-linear distortion coefficient equal to the division factor of the reference voltage divider 9. However, the difference between the different time drifts of the two channels of the differential comparator 5 leads to the fact that the appearance of the signal at the output of the differential comparator 5 violates the equality of the effective values of the output. The generator 2 high harmonics and the adder 8 so that the output of the differential comparator 5 is practically zero signal After a certain time of continuous operation, the signal from the control device disconnects the output of comparator 5 from the input of block 3 by means of the opening contact 4, while the output corresponding to the non-linear distortion calibrator output maintains a signal corresponding to the opening opening of terminal 4. After that, the control block switches the synchronously activated contacts .act groups 7, swapping the signal at the inputs of the differential comparator 5. At the output of the differential comparator 5, a signal appears corresponding to the difference in the effective values of the output voltage of the generator 2 of higher harmonics and the adder 8 at the time of disconnection of the thermal contact 4, due to the difference in the time drift of the two channels of the differential comparator 5. After the end of the transition process-. Ca, caused by switching the inputs of the differential comparator 5, the signal from the control unit enters, block 3, changing the sign of the output signal of block 3 to the control input of the first harmonic generator 1 and simultaneously connects the input of block 3 to the output of the differential comparator 5 via contact . 4 and the evolved signal at the control input of the first harmonic generator 1 changes the output voltage, thereby changing the voltage at the output 10 of the calibrator and establishes the equality of the effective values of the output voltages of the high harmonics generator 2 and the adder 8. At the output 10 thus the error due to the different drift of the two channels of the differential comparator 5 is eliminated. After some time, all the switchings are repeated, and again the error that has occurred is eliminated. Calibrator does not have periodic intermittent. This calibration, i.e. There is no need to calibrate the differential comparator on one reference signal. As block 3, a differential amplifier can be used, the inputs of which contain storage capacitances and alternately (according to the sign of influence on the control input of the generator) are connected to the differential output. comparator 5, the time for setting the nonlinear distortion coefficient is determined by the time for setting the coefficient on the exemplary voltage divider 9, and setting the equality of the effective values of the output voltages of the high harmonic generator 2 and the adder B and eliminating errors in this equality is done automatically The formula for calculating the nonlinear distortions containing the first harmonic generator is connected via an adder with one input of a differential comparator, the second input of which is connected to a higher generator th harmonics venno A direct and through an exemplary divider. the voltage is connected to the second input of the adder, and the output of the differential comparator is connected to the control input of the first harmonic generator, characterized in that, in order to improve accuracy, two synchronously triggered contact groups, a sampling, storage and output unit, are opened in it a contact and a control unit, with the switching contacts of synchronously actuated contact groups connected to the inputs of the differential comparator, the closing contact of the first and the opening contact of the second contact group connected to the output of the generator of higher harmonics, the opening contact of the first and the closing contact of the second contact group are connected to the output of the adder, the output of the sampling, storage and information output unit is connected to the control input of the first harmonic generator, and the input through the opening contact is connected to the output of the differential comparator, the control unit is associated with a unit for sampling, storing and retrieving information, an interrupting contact and synchronously operating 7 "contact groups. Sources of information taken into account in the examination 1. USSR author's certificate number 456225, CL. G 01 R 23/20, 1974. 2. The author's certificate of the USSR (584259, CL. G 01 R 23/20, 1977.