راسمة الاهتزازات - القياسات في الدارات الالكترونية .. الإلكترونيات

Vibration plotter - Measurements in electronic circuits .. Electronics

Vibration plotter

The cathode ray tube is used to display the image of phenomena that change with time, such as changes in voltage and current that cannot be determined by ordinary measuring devices. When the cathode ray falls on the screen of the device, a bright dot (262) appears on it that determines the location of the rays.

It is worth noting that applying an alternating voltage to the vertical deflecting plates of the device leads to the beam being deflected from top to bottom and vice versa, thus forming a vertical straight line that indicates the voltage value. Also, connecting an alternating voltage to the horizontal plates produces a horizontal line, and by combining the horizontal and vertical deflection phenomena together, we can display different things on the screen.

To obtain an image of the alternating wave, it must be applied to the basic plates that give a vertical scan, and a horizontal scan must be performed using a saw vibrator (263A). We can also direct the input to the horizontal and vertical deflection plates and obtain different models that can be used to determine the relationship between the frequency of a specific input and the frequency of the other input (263b).

262 - Using the oscilloscope in testing.

263 - Waveform on the oscilloscope screen.

The signals to be studied may need amplification (264). In this case, the signals pass through a vertical amplifier that increases the intensity of weak signals. In addition, the "time base", i.e. the saw wave generator, scans the spot across the screen horizontally. The synchronization circuits take part of the input signal to use it in igniting the time base. So that the movement of the image formed on the screen can be stopped to study it, especially complex signal images. In addition, the horizontal amplifier can be operated inside the device, and in this case the second signal moves the spot horizontally. The oscilloscope is equipped with a "power supply" that provides current to each of its different sections separately, especially the tube that. It requires a voltage of up to 1000 volts or more at a low current.

It is possible to study and show all kinds of different phenomena on the oscilloscope. An example of this is the amplifier that generates distortion resulting from its third harmonic and thus gives undesirable results (265), which can be known by the oscilloscope.

264 - Cathode ray oscilloscope.
265 - Distortion resulting from the third harmonic.