RU2084903C1 - Oscilloscope - Google Patents

Abstract

FIELD: radio engineering instruments. SUBSTANCE: device has four commutators 2, 3, 14, 17, cathode-ray tube 4, sweep circuit 5, synchronization unit 6, two stroboscopic converters 9, 10 delay line 11, voltage meter 12, two oscillators 15, 16, first adder 13 and deviation unit 1, which input is connected to measured signal line, and output is connected to first input of first commutator 2 and second input of first stroboscopic converter 9. Output of first stroboscopic converter is connected to input of voltage meter 12. First and second inputs of cathode-ray tube are connected to outputs of respectively second commutator 3 and first commutator 2. First output of sweeping circuit 5 is connected to first input of second commutator and second input of second stroboscopic converter. Second output of sweeping circuit is connected to second inputs of first and second commutators . First output of first generator 15 and output of second generator 16 are connected respectively to first and second inputs of third commutator 14. Outputs of second stroboscopic converter and third commutator are connected respectively to first and second inputs of first adder 13. EFFECT: increased functional capabilities.

Description

 The invention relates to radio measurement technology and can be used in oscillography.

 Known oscilloscope [1] However, this device is characterized by the great complexity of combining the brightness mark with the waveform, as well as the low accuracy of combining the mark with the waveform, which is due to the mutual masking of the mark and the waveform line when they come closer to a distance less than that at which the mark touches and waveform lines.

 Known oscilloscope [2] However, this device is characterized by low measurement accuracy, which is due to the distortion of the cathode ray tube, and the high complexity of the measurements, due to the presence of the operation of visual search for extreme points on the waveform.

 The closest technical solution to the invention is an oscilloscope [3] containing three switches, a cathode ray tube, a scan unit, a synchronization unit, two stroboscopic converters, a delay line, a voltmeter, two generators, a first adder and a deviation unit, the input of which is connected to the measured bus signal, and the output of the deviation unit is connected to the first input of the first switch and the second input of the first stroboscopic converter, the output of the first stroboscopic converter is connected to the third the input of the first switch and the input of the voltmeter, the first and second inputs of the cathode ray tube are connected to the outputs of the second and first switches, respectively, the first output of the scan unit is connected to the first input of the second switch and the second input of the second stroboscopic converter, the second output of the scan unit is connected to the second inputs the first and second switches, the first output of the first generator and the output of the second generator are connected to the first and second inputs of the third switch, respectively, the outputs of the second the stroboscopic converter and the third switch are connected to the first and second inputs of the first adder, the output of which is connected to the third input of the second switch, the output of the delay line is connected to the first inputs of the first and second stroboscopic converters, the inputs of the scan unit and the delay line are connected to the output of the synchronization block, input which is connected to the synchronization bus.

 However, the prototype has low accuracy and high complexity of the measurements. The amplitude of the pulse having an outlier (or damped oscillations) at the end of the front and a cleavage (slope) of the vertex is determined at the point of intersection of the front line with the straight line that extends the rectilinear inclined part of the vertex following the outlier (or damped oscillations). At the prototype, an oscillogram of the measured pulse is formed on the screen, the brightness point is located on the waveform line, which is moved along the waveform by changing the delay line delay, and the scan line intersects the brightness mark, each of the points on which corresponds to the equal signal signals at the prototype input. The waveform of the pulse, in comparison with the volt-second dependence of the pulse, is distorted due to the distortion of the cathode ray tube. Due to the presence of a cleavage at the peak of the measured pulse, it is impossible to combine the peak line with the sweep line. To find the location on the waveform of the pulse amplitude measurement point, the operator visually extends the peak cleavage line to the front line and sets the brightness mark at the intersection point of the pulse waveform front line and the visually extended pulse wave peak line. The value of the signal at the input of the deviation unit at the moment preceding the moment of the appearance of the pulse at the output of the delay line by the delay time by the deviation unit is equal to the voltage measured by a voltmeter divided by the gain of the deviation unit.

 However, the prototype has a large measurement error due to the low accuracy of the search point of the amplitude measurement point visually produced by the pulse waveform. The low accuracy of the prototype is also caused by the distortion of the waveform shape due to the distortion of the cathode ray tube, as a result of which the linear dependence of the chip of the peak of the pulse on the volt-second dependence is reproduced on the waveform by a non-straight line, which increases the error of the search for the measurement point of the pulse amplitude.

 The great complexity of measurements by the prototype is due to the complexity of visually performed operations when searching for the location of the pulse amplitude measurement point.

The purpose of the invention to increase accuracy and reduce the complexity of measurements
This goal is achieved by the fact that the oscilloscope contains three switches, a cathode ray tube, a scan unit, a synchronization unit, two stroboscopic converters, a delay line, a voltmeter, two generators, a first adder and a deviation unit, the input of which is connected to the measured signal bus, and the output of the deviation unit is connected to the first input of the first switch and the second input of the first stroboscopic converter, the output of the first stroboscopic converter is connected to the input of the voltmeter, the first and second the first inputs of the cathode ray tube are connected to the outputs of the second and first switches, respectively, the first output of the scanner is connected to the first input of the second switch and the second input of the second stroboscopic converter, the second output of the scanner is connected to the second inputs of the first and second switches, the first output of the first generator and the second output of the second generator is connected to the first and second inputs of the third switch, respectively, the outputs of the second stroboscopic converter and the third commute tori are connected to the first and second inputs of the first adder, the output of which is connected to the third input of the second switch, the output of the delay line is connected to the first inputs of the first and second stroboscopic converters, the inputs of the scan unit and the delay line are connected to the output of the synchronization unit, the input of which is connected to the bus synchronization, a second adder and a fourth switch are introduced, the first and second inputs of which are connected to the second output of the first generator and the output of the second generator, respectively the outputs of the first stroboscopic converter and the fourth switch are connected to the first and second inputs of the second adder, the output of which is connected to the third input of the first switch, respectively.

 In FIG. 1 shows a block diagram of an oscilloscope; in FIG. 2 shows the image on the screen of the oscilloscope.

 In figures 1 block deviation; 2, 3, 14 and 17, respectively, the first, second, third and fourth switches; 4 cathode ray tube; 5 - scanner; 6 block synchronization; 7 sync bus; 8 bus of the measured signal; 9 and 10, respectively, the first and second stroboscopic converters; 11 delay line; 12 voltmeter; 15 and 16, respectively, the first and second generators; 13 and 18, respectively, the first and second adders; 19 waveform of the measured pulse; 20 brightness mark; 21 - scan line.

 The oscilloscope operates as follows. From the bus 8 of the measured signal to the input of the unit 1 deviations with a repetition period of 0.1 to 10 ms received measured pulses with a duration of less than a third of the repetition period. The deviation unit 1 delays and amplifies the pulses arriving at its input. From the output of the deviation unit 1, pulses are fed to the first input of the first 2 switches and the second input of the first 9 stroboscopic converter. From the output of the first 9 stroboscopic converter, the signal is fed to the input of the voltmeter 12 and the first input of the second 18 adder. After each pulse received at the first inputs of the first 9 and second 10 stroboscopic converters, the signals that were at the second inputs at the time the pulse arrived at the first inputs are held at their outputs. The signal at the outputs of the first 13 and second 18 adders is equal to the sum of the signals received at the first and second inputs. When applying a pulse to the second inputs of the first 2 and second 3 switches, their outputs are connected to the first inputs; in the absence of a pulse at the second inputs, the outputs of the first 2 and second 3 switches are connected to the third inputs. When applying a pulse to the second inputs of the third 14 and 17 of the switch, their outputs are connected to the first gatherings; in the absence of a pulse at the second inputs of the third 14 and fourth 17 switches, their outputs are disconnected from the first inputs. The signal from the output of the second 18 adder is fed to the third input of the first 2 switch. From the synchronization bus 7, either synchronization pulses or measured pulses are received at the input of the synchronization unit 6. The synchronization unit 6 generates pulses and feeds them to the input of the delay line 11 and the input of the scan unit 5. The delay line 11 delays the pulses arriving at its input. From the output of the delay line 11, the delayed pulses are fed to the first inputs of the first 9 and second 10 stroboscopic converters.

 When a pulse arrives at the input of the sweep unit 5, a sawtooth sweep voltage is generated at its first output, and a rectangular pulse is generated at the second output, and the moments of the start of the sawtooth and rectangular pulses coincide, the times of the end of the sawtooth and rectangular pulses also coincide. Sawtooth pulses from the first output of the scanner unit 5 are fed to the first input of the second 3 switch and the second input of the second 10 stroboscopic converter. The signal from the second output of the scan unit 5 is fed to the second inputs of the first 2 and second 3 switches. The signal from the output of the second 10 stroboscopic converter is fed to the first input of the first 13 adder, the second input of which receives the signal from the output of the third 14 switch. The signal from the output of the fourth 17 switch enters the second input of the second 18 adder. The first 15 generator generates a sinusoidal signal with a frequency of 100 kHz, and the signals at the first and second outputs are out of phase and have independent amplitude regulators of the signals.

 The second 16 generator generates with a repetition rate of 4 Hz (repetition period of 250 ms) a series (burst) of pulses, and in each series of 7 pulses with a duration of 10 ms, followed by a repetition period of 20 ms. The signal from the first and second outputs of the first 15 generator is supplied to the first inputs of the third 14 and fourth 17 switches, respectively. The signal from the output of the second 16 generator goes to the second inputs of the third 14 and fourth 17 switches. The signal from the outputs of the first 2 and second 3 switches enters the second and first inputs of the cathode ray 4 tube, respectively. The signal from the output of the first 13 adder is fed to the third input of the second 3 switch. When signals are received from the measured signal bus 8 and the synchronization bus 7, the pulse from the output of the synchronization unit 6 starts the scan unit 5, which generates a sawtooth pulse, which passes through the second 3 commutator to the first input of the cathode ray 4 tube.

The amplified measured signal from the output of the deviation unit 1 through the first 2 switch is fed to the second input of the cathode ray 4 tube. As a result, an oscillogram 19 of the measured pulse is formed on the screen of the cathode ray 4 tube. At one point in time of the formation of the waveform 19 of the measured pulse from the output of the delay line 11, a pulse arrives, which causes the stroboscopic signal converters that were present at the second and first inputs of the cathode ray 4 tube at the moment of the presence of the pulse to be present at the outputs of the first 9 and second 10 output line 11 delay. After the completion of the formation of the waveform 19 of the measured pulse and before the formation of the next waveform 19 of the measured pulse, the signals from the outputs of the first 13 and second 18 adders are fed to the first and second inputs of the cathode ray 4 tube, respectively; wherein:
a) during periods of absence of pulses at the output of the second 16 generator, the first and second inputs of the cathode ray 4 tube receive only signals from the outputs of the second 10 and first 9 stroboscopic converters, which ensures the formation of a brightness mark 20 on the screen located in the place of the oscillogram 19 of the measured the pulse that was formed on the screen at the time of the appearance of the pulse at the output of the delay line 11;
b) during the period of the presence of a pulse at the output of the second 16 generator, the first input of the cathode ray 4 tube receives the sum of signals from the output of the second 10 stroboscopic converter and the first output of the first 15 generator, and the sum of signals from the output goes to the second input of the cathode 4 tube the first 9 stroboscopic converter and from the second output of the first 15 generator, which ensures the formation on the screen of a scan line 21 intersecting the luminance 20 mark; adjusting the voltage at the first or second outputs of the first 15 generator provides a change in the slope to the horizontal of the scan line 21.

 During the formation of a series of pulses by the second 16 generator, a luminance 20 mark and a sweep line 21 are formed alternately with a repetition rate of at least 50 Hz, which eliminates the flickering of the luminance 20 marks and a scan line 21 during the formation of a series of pulses by the second 16 oscillator. Scan line 21 flashes at a frequency of 4 Hz. When changing the delay of the delay line 11, the luminance 20 mark moves along the oscillogram 19 of the measured pulse, while the scan line 21 also moves, crossing the luminance 20 mark. The scan line 21 is formed by proportionally changing the signals at the first and second inputs of the cathode ray 4 tube, and therefore, by changing the magnitude of the signal at the first and second outputs of the first 15 oscillator, you can combine the scan line 21 with a linearly decreasing waveform. To measure the amplitude of the pulse, it is necessary to place the luminance 20 mark at the point of measurement of the amplitude of the oscillogram 19 of the measured pulse, then divide the measured voltmeter 5 readings by the gain of the deviation unit 1. To set the brightness mark 20 on the amplitude measurement point of the waveform 19 of the measured pulse, position the brightness mark on the front line of the waveform 19 of the measured pulse at a level between outliers after the front, then adjust the sweep line 21 to set the scan line 21 parallel to the peak line of the waveform 19 of the measured pulse; thereafter, by moving the brightness mark 20 along the front line of the measured waveform waveform 19 and adjusting the slope of the scanning line 21, align the scanning line 21 with the peak of the measured pulse waveform 19, as shown in FIG. 2.

Improving the accuracy of measurements due to:
a) Exclusion of the error in visual operations to find the location of the amplitude measurement point on the oscillogram 19 of the measured signal;
b) The exception of the error caused by the distortion of the shape of the waveform 19 of the measured pulse in comparison with the volt-second dependence of the measured pulse due to distortion of the cathode ray 4 tube.

 Note: According to [4], distortion is the geometric distortion of the reproduced image. Geometric distortion can be barrel-shaped, pillow-shaped, trapezoidal, S-shaped. Due to distortion, when an alternating voltage is applied to one of the inputs of the cathode ray 4 tube and a constant voltage is applied to the other of their inputs, an indirect (curved) line is reproduced on the screen, for example, in the form of an arc or letter S.

 The decrease in the complexity of the measurements is due to the exception of the procedure of visual search for the location of the amplitude measurement point on the oscillogram 19 of the measured pulse by visually extending the peak cleavage line to the front line.

Claims (1)

 An oscilloscope containing three switches, a cathode ray tube, a scan unit, a synchronization unit, two stroboscopic converters, a delay line, a voltmeter, two generators, a first adder and a deviation unit, whose input is connected to the measured signal bus and the output is to the first input of the first switch and the second input of the first proboscopic transducer, the output of the first stroboscopic transducer is connected to the input of the voltmeter, the first and second inputs of the cathode ray tube are connected to the outputs, respectively the second and first switches, the first output of the scanner is connected to the first input of the second switch and the second input of the second stroboscopic converter, the second output to the second inputs of the first and second switches, the first output of the first generator and the output of the second generator are connected to the first and second inputs of the third switch, the outputs of the second stroboscopic converter and the third switch respectively to the first and second inputs of the first adder, the output of which is connected to the third input m of the second switch, the output of the delay line is connected to the first inputs of the first and second stroboscopic converters, the inputs of the scan unit and the delay line with the output of the synchronization unit, the input of which is connected to the synchronization bus, characterized in that, in order to increase the accuracy and reduce the complexity of measurements, the second adder and the fourth switch, the first and second inputs of which are connected respectively to the second output of the first generator and the output of the second generator, the outputs of the first stroboscopic conversion ovatelya and fourth switch are connected respectively to first and second inputs of the second adder, the output of which is connected to the third input of the first switch.

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