SU1112289A1 - Cathode-ray oscillograph having digital memory for storage signal under investigation - Google Patents

Abstract

ELECTRON-BEAM OSCILLOGRAPH WITH DIGITAL FORM. WE ARE INVESTIGATED SIGNAL, containing a vertical deflection amplifier, the input of which is connected to the signal bus, and the output is connected to the first input of the synchronization unit and the analog-digital converter input, the control input of which is connected to the output of the control unit and the control inputs of the scanner, digital the storage unit and the digital-analog converter, and the output is connected to the input of the digital storage unit, the output of which is connected to the input of the digital-analog converter, the output connected to the vertical The deflection plates of the cathode ray tube, the horizontal deflection plates of which are connected to the output of the scanner, the input connected to the output of the synchronization unit, the second input of which is connected to the clock signal bus, which is different in order to reliably image the investigated harmonic signal i screen of the cathode ray tube, it is equipped with a time converter (L code and a switch, the input of which is connected to the output of the vertical deflection amplifier, the output - to the input of the transducer the time caller is the code and the control input is from the control input of the time converter the code and the output of the control unit.

Description

The invention relates to electrical measuring technology and can be used to memorize the shape of the signal under study at wide polyster frequencies. A cathode-ray oscilloscope is known that contains a vertical deflection amplifier, a synchronization unit, an analog-digital converter, a digital storage unit, a digital-to-analog converter, a horizontal deflection path, an electron-beam tube, and a control unit based on a microprocessor that is connected to the oscilloscope information nodes bus, bus control and address bus L. A disadvantage of this device is the impossibility of displaying the investigated harmonic signal on the screen of a cathode ray tube when one period is less than 5-10 samples. Closest to the invention of the technical nature is. an electron beam oscilloscope with a digital memory of the waveform of the signal under investigation, containing a vertical deflection amplifier, the input of which is connected to the bus of the signal under study, and the output is connected to the first trigger of the synchronization unit and the analogue of the digital converter, the control input of which is connected to the output of the control unit input inputs of the scanner, the digital storage unit and the digital-to-analog converter, and the output to the input of the digital storage unit whose output is connected to the input of the digital-analogue A converter with an output connected to a vertically deflecting plates of a cathode-ray tube, whose horizontal plates are connected to the output of the scanner, the input of the synchronization unit connected to the output, the second input of which is connected to the clock signal 121. A disadvantage of the known devices is the low confidence images of the investigated harmonic signal on the screen of the electron-beam tube, due to the discrepancy between the sampling frequency and the period of the signal under study. The aim of the invention is to increase the reliability of the image of the investigated harmonic signal on the screen of the cathode ray tube. The goal is achieved by the electron-beam oscilloscope with digital memorization of the signal under study, containing a vertical deflection amplifier, the input of which is connected to the signal bus, and the output is connected to the first input of the synchronization unit and the input of the analog-digital converter, the control input of which is connected to the output of the unit control and control inputs of the scanner, the digital storage unit and the digital-to-analog converter, and the output with the input of the digital storage unit whose output Connected to the input of a digital-to-analog converter whose output is connected to vertically deflecting plates of a cathode-ray tube, whose horizontal deflection plates are connected to the output of a scanner, the input connected to the output of a synchronization unit, the second input of which is connected to a clock signal bus and a switch whose input is connected to the output of the vertical deflection amplifier, the output to the input of a time converter is a code, and a control input with a control input of the preamp Timer - code and block output. management The drawing shows the structures on the electrical circuit of an electron-beam oscilloscope (ELO). The device consists of an amplifier 1 vertical deflection, a synchronization unit 2, an analog-digital converter (ADC) 3, a digital storage unit 4, a digital-analog converter (D / A converter) 5, a cathode ray tube (CRT) 6, a scanning unit 7, a switch 8, a converter 9 time - code and control unit 10. The input of the vertical deflection amplifier 1 is connected to the signal bus, and the output is connected to the first input of the synchronization unit 2 and the analog-digital converter 3 input, the control input of which is connected to the output of the control unit 10 and the control inputs of the scanner 7, the digital storage unit 4 and digital to analog

3

converter 5, and an output with an input of a digital storage unit 4 whose output is connected to an input of a digital-to-analog converter 5, an output connected to vertically deflecting plates of a cathode ray tube 6, horizontal deflection plates of which are connected to an output of a scanner 7, connected to an output synchronization unit 2, the second input of which is connected to the clock pulse bus. The input of the switch 8 is connected to the output of the vertical deflection amplifier 1, the output to the input of the time converter 9 is the code, and the control input to the control input of the time converter 9 is the code and the output of the control unit 10.

The vertical deflection amplifier 1 includes an attenuator, which is used to change the input signal level,

The structure of the scan unit 7 includes a D / A converter whose output signal performs horizontal scanning of the image on the screen of the CRT 6.

Converter 9 time - the code is made on the basis of the pulse counter and high-frequency generator

jraKTOBbix pulses.

The control unit 10 is made on the basis of a microprocessor (MP) of the 580 series, connected to the A / D converter 3, 4 DAC block 5, sweep block 7, switch 8 and time converter 9 - the code of the information bus, the control bus and the address bus. The block diagram of the control unit includes a permanent storage device (ROM), in which programs for various operating modes of ELO are recorded, including a sinusoidal interpolation program, a system controller that generates control signals necessary for operation of all instrument nodes, Character ROMs - for recording alphabet based indications on a CRT screen, controlling a microprocessor device that performs arithmetic, logic, and register operations

The device works as follows.

The harmonic signal under study acts on the input of the vertical deflection amplifier 1 and is amplified by it. After the analog-to-digital converter, implemented by the ADC 3, you 89

The bobbins of the amplified signal in the form of a binary parallel code are fed to block 4 and stored there. On command from the control unit 10, the signal removed from the memory of unit 4 is subjected to digital-to-analog conversion to D / A converter 5 and the analog signal acts on the vertical deflection plates of the CRT 6. The image scan of the test signal on the screen of the CRT 6 is produced by a digital-analog converter of information corresponding to the position of the sampling points of the signal under study in block 4, This conversion is carried out in block 7 of the sweep. The control unit 10 reads from the scan unit 7 a digital code corresponding to the set

the sweep ratio, and stores it in the memory of block 4, then at the command of control block 10 for a time equal to, for example, every tenth or hundredth period of the input signal,

switch 8 is turned on. In this case, a momentary connection of the converter input 9 is time — the code to the output of the vertical deflection amplifier 1 does not distort

information stored in block 4, and distortion of the image of the signal under investigation on the screen of the CRT 6. Transducer 9 time - the code converts the time interval equal to the period

the signal under investigation, into a digital code, which, at the command of control unit 10, is read through this block into the memory of block 4 and is stored there. At the same time, high-accuracy time conversion is not necessary, since the digital code of the converter 9 sets the sampling frequency of the signal under study (for example, from 10 Hz to 25 MHz) and creates the necessary information for comparison with the code of the scanner 7. If the code read from the sweep unit 7 does not correspond to the code from the output of the time converter 9, the code

The control unit 10 makes a decision to change the ELO sweep ratio so that the number of samples per period of the signal under study is at least 2.5.

The device allows you to eliminate the distortion (truncation) of the signal, which increases the accuracy of reproduction of the form of the signal under study.

Claims (1)

I ELECTRON BEAM Oscillograph with digital memorization of phores, we have the signal under test, containing ¹ vertical deviation amplifier, the input of which is connected to the studied signal bus, and the output - with the περί input of the synchronization block and the input of the analog-to-digital converter control unit and control inputs of the scan unit, digital storage unit and digital-to-analog converter, and the output - with the input of the digital storage unit, the output of which is connected to the input of the digital log converter connected to vertically deflecting plates of the cathode ray tube, horizontally deflecting plates of which are connected to the output of the scan unit, input connected to the output of the synchronization unit, the second input of which is connected to the sync signal bus, characterized in that, in order to increase the reliability of the image under study a harmonic signal on the screen of the cathode ray tube, it is equipped with a time code converter and a switch, the input of which is connected to the output of the amplifier tikalnogo deflection output - to the input of inverter time - code, and a control input - to the control input inverter time - code and the output control unit.