SU1307417A1 - Device for cadibration checking of extraneous amplitude modulation meters - Google Patents

Abstract

The invention relates to instrumentation. The goal is to expand the functionality of the device for calibration of parasitic amplitude modulation (AH) meters. It is achieved by that. that the device containing the generator (D) 1, the controlled voltage divider 2 and the control signal generator 9 are entered in D 6, voltage regulators 5, 7, amplitude modulator 4, voltmeter 8 and switch 3. The invention allows expand the nomenclature of the normalized values of the AM coefficient and modulating frequencies for any modulation law. 1 silt, (L with about 4;

Description

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This invention relates to instrumentation engineering, in particular to magnetic recording metrology.

The purpose of the invention is to expand the functionality by expanding the required nomenclature of normalized values of the amplitude modulation coefficient and modulating frequencies under any modulation law.

The drawing shows the functional diagram of the device for calibration of parasitic amplitude modulation meters,

The device contains a first generator 1, a controlled voltage divider 2, a switch 3, an amplitude modulator 4, a first voltage regulator 5, a second generator 6, a second voltage regulator 7, a voltmeter 8, a control signal generator 9, a terminal 10 for connecting a device to be tested, the output of the first generator I is connected via a controlled voltage divider 2 to the first contact of switch 3 and to the first input of an amplitude modulator 4, the second input of which is connected through the first voltage regulator 5 the control unit and the input of the control signal generator 9, and through the second voltage regulator 7 - with the input of a voltmeter 8, the control input of a controllable voltage divider 2 is connected to the output of the control signal generator 9, the output of the amplitude modulator modulator yen to the second switch contact 3, the common contact of which is connected to terminal 10 for connecting a calibrated instrument.

The device works as follows

A terminal for spurious amplitude modulation is connected to terminal 10. The first oscillator I generates qignal of the carrier frequency, which simultaneously enters the input of the controlled divider 2 voltage and the first input of the amplitude modulator 4, the second oscillator 6 converts the modulating frequency signal, and the output signal can be as sieve-shaped .

hook and right angle

2, the square-wave modulating frequency signal from the output of the second generator 6 is simultaneously fed to the input of the imaging unit 9 of the signal

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five

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five

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control and to the input of the first voltage regulator 5; From the output of the control signal generator 9, the rectangular waveform signal of the required voltage and power is fed to the control input of the controlled voltage divider 2,

At the output of the controlled voltage divider 2, an amplitude modulated signal according to the law of rectangular imguls with a duty cycle 2 is formed, the amplitude modulation coefficient of which is given by the ratio of the divider resistors. At the same time, the accuracy of setting the amplitude modulation coefficient is determined by the accuracy of the values of the divider resistors.

Thus formed, an exemplary signal of measurement information through the closed contacts 11 of the switch 3 is fed to the input of a detectable parasitic amplitude modulation meter, where it is demodulated and displayed. The indicator readings are fixed by the operator with the maximum possible accuracy. Then the switch 3 is transferred to the position corresponding to the closed contacts 12. At the same time, the measuring information signal from the output of the amplitude modulator 4, also modulated by the law of square and mplus with a duty cycle of 2 with the same frequency, as a sample signal. In the parasitic amplitude modulation meter being tested, the measurement information signal is also demodulated and indicated. With the help of the first voltage regulator 5, the indicator readings are equalized by the operator with the previously fixed ones, i.e. thus, using a comparison, the sensitivity of the amplitude modulator 4 is normalized. Then, at the output of the second generator 6, the operator establishes a sinusoidal waveform (the amplitude and frequency do not change) and using the second voltage regulator 7, the voltmeter 8 is set so that their numerical expression corresponds to the value of the amplitude modulation coefficient specified by the controlled voltage divider 2.

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Changing the voltage of the modulating signal at the second input of the amplitude modulator 4, using the first voltage regulator 5, the operator to check the basic error of the calibrated parasitic amplitude modulation meter sets the required range of amplitude modulation coefficients using a voltmeter 8 as indicator of the set values of the amplitude modulation coefficient, comparing with its readings of the instrument being checked. The basic measurement error is determined in this way in the usual way.

Claims (1)

Invention Formula A device for calibrating parasitic amplitude modulation meters, comprising a generator, a controlled voltage divider, a control signal generator and a terminal for 174 Key verification device, characterized in that, in order to extend the functionality, it additionally introduced a second generator, two voltage regulators, an amplitude modulator, a voltmeter and a switch, with the output of the first generator connected to the first contact of the voltage divider and the first input of the amplitude modulator, the second input of which through the first voltage regulator is connected to the output of the second generator and the input of the control signal generator, and through the second regulator The voltage torus is connected to the input of a voltmeter, the control input of the controlled voltage divider is connected to the output of the control signal generator, the output of the amplitude modulator is connected to the second contact of the switch, the common contact of which is connected to the terminal for connecting the calibration instrument.