SU586562A1 - Device for measuring time interval duration in electron-beam oscillographs - Google Patents

Description

The device contains an amplitude comparator 1, a scanner geierator 2, a reference voltage source 3, an analog-digital converter 4, a digital-analog converter 5, a power supply unit 6, a control unit 7, an indicator 8, a cathode-ray tube (CRT) 9, a large-scale inverter 10 .

The device works as follows.

In the initial state, the output at the output of converter 5 is zero. This is achieved by setting the memory unit 6 to a state where zeros are entered in all bits. The installation is performed by control unit 7. Sweep generator 2 generates horizontal voltage pulses that support the image of the signal UX under study on the oscilloscope's CRT screen. Analog-to-digital converter 4 measures the output of the source 3 of the reference voltage. The measurement results of the transducer 4 through the transducer 10 are fed to the indicator 8, where they are displayed in a digital code. To measure the duration and duration of the time between two specific points in the image of the signal Lx under study, the first point in the signal image is illuminated along the Z axis. The backlight is produced with the help of source 3 and comparator 1. At the time when the voltages are equal at the inputs of comparator 1, it generates pulsed modulation pulses. To highlight the first point, the voltage of source 3 is changed until its output voltage equals the voltage of sweep generator 2 corresponding to the first point. The first point of the image Ux corresponds to the voltage Ui of the source of the reference voltage 3. After the first point is illuminated, the command from the control unit 7 of the converter 4 transmits the code corresponding to the voltage Ui, is transferred to the memory block 6 and further to the converter 5. the output of converter 5 becomes L, and thus, the voltages at the inputs of converter 4 become equal to each other; The measurement result of the transducer 4 is zero, which is indicated on the indicator 8. After that, the voltage of source 3 is manually changed to highlight the second point of the image U on the oscilloscope's CRT screen. If the second point corresponds to voltage 1/2 of generator 2, then the voltage of source 3 at the time of illumination will also be equal to / 2. The value of Lz is: (J, U, + kf,

where k is a constant coefficient characterizing the steepness of the sweep voltage;

x is the duration of the measured interval. Analog-to-digital converter 4 measures the voltage difference by the inputs:

, -U ki,

that is, the measurement result, taking into account the scale factor, will be equal to the duration of the measured time interval between two points of the image of the signal on the screen of the oscilloscope.

Thus, the measurement uncertainty is determined only by the faults of a digital-analog and digital-analog converters, as well as the non-linearity of the sweep voltage.

Claims (2)

1. “Oscilloscope CI-49. Technical description and operating instructions, 1960 2. US Patent Lo 3755261, cl. 324-181, 1973. + Y  j