SU1394037A1 - Device for recording amplitude-frequency characteristics - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure the frequency characteristics of instruments in test benches. The invention allows simultaneous visual inspection and recording of the output and input signals of the device under study, including the frequency-controlled ones. The device contains an oscillation generator 1, the device under study 2, an oscilloscope oscilloscope 3, a tape recorder 4, a controlled attenuator 5, an amplitude detector 6. The generator 1 contains a multivibrator 7, an element 8 of the frequency control of the multivibrator, a discrete attenuator 9. The device 2 contains a block 10 and block 11 LF. The amplitude-modulated oscillations arrive at the input of the detector 6, where you select their envelope, which is recorded by the oscilloscope 3. For normal operation of the device, the frequency of changing the frequency of the oscillator 1 oscillation does not exceed the bandwidth of the loop oscilloscope. 2 Il.

Description

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1394037

The invention relates to a measurement technique and can be used to measure the frequency characteristics of the instruments in test walls.

The aim of the invention is the simultaneous visual inspection and recording of the input and output signals of the device under study, including the frequency-controlled ones. I FIG. 1 shows a functional diagram of the device; figure 2 - timing charts of the signals at the outputs of the respective units of the device. The device contains oscillator 1, device 2 under test, oscilloscope loop 3, tape recorder 4, controlled attenuator 5, amplitude detector 6. Generator 1 oscillation-20 SRI contains multivibrator 7, element 8 frequency control of multivibrator 7 and discrete attenuator 9, Investigated device 2 contains a high-frequency unit 10 and a low-frequency unit 11. As at-25 measure of the device 2, you can use a radio receiver or a phase-locked loop (PLL). In the first case, block 11 is a detector and a low-frequency amplifier, and block 10 is a receiver RF circuit. In the second case, block 10 is a cascade of amplification of signals from the F11C system, and block 1 1 is a phase detector.

The device works as follows.

The oscillations from the output of the generator 1 are fed to the input of the device 2. In this case, the amplitude of the oscillations is known and fixed by an attenuator 9.

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The device generates a signal, which is its response to the frequency of the generator 1. This signal on the communication line is fed to the first inputs of the oscilloscope loop-3 and tape recorder 4 for registration.

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At the same time, oscillations from the generator 1 output go to the information input of the controlled attenuator.

Trol and records of any, including frequency-manipulated, input and output signals of the device under study, a controlled attenuator and an amplitude detector are entered into it, the output of the oscillator is connected to the information input of the controlled

5. Since the attenuator control input is a 50 attenuator whose output is connected

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Thus, the oscillations at the output of the controlled attenuator 5 are endowed with amplitude modulation, the depth of which is determined by the frequency of the oscillator 1.

The amplitude-modulated oscillations from the output of the attenuator 5 on another line of communication are fed to the second input of the tape recorder 4. The amplitude modulation of oscillations during secondary processing does not interfere with the selection of the oscillation frequency, which is an information parameter of the signal.

In addition, the amplitude-modulated oscillations arrive at the input of the amplitude of the detector detector 6, where it is distant from their envelope. The amplitude of the selected envelope, taking into account the characteristics of the controlled attenuator 5 and the amplitude detector 6, unambiguously corresponds to the frequency of the input signal of the device 2. The detector enveloped by the detector 6 enters the second input of the oscilloscope loop 3 and records it.

For normal operation of the device, the frequency of changing the frequency of the oscillator 1 oscillations should not exceed the bandwidth of the loop oscilloscope 3.

Claims (1)

Invention Formula A device for recording amplitude-frequency characteristics, containing an oscillator, the output of which is connected to one of the terminals for connecting the device under study, the other terminal is connected to the first inputs of a tape recorder and loop oscilloscope, characterized in that Trol and records of any, including frequency-manipulated, input and output signals of the device under study, a controlled attenuator and an amplitude detector are entered into it, the output of the oscillator is connected to the information input of the controlled attenuator whose output is connected torus 5 is mechanically or electrically connected to frequency control element 8 of multivibrator 7 (mechanical connection is shown in Fig. 1), attenuation of amplitude of its 55 input signal by attenuator 5 is unambiguously equal to oscillation frequency of oscillator 1. the control input to the amplitude detector, the output of which is connected to the second input of a loop oscilloscope, is controlled mechanically or electrically with the control element of the oscillator G. ... ofn n .. pin V, 6, -e t Figg