Electronics: Oscilloscope

Below is a picture of a cathode tube laid bare. This is what also goes on inside of an oscilloscope. The green dot that is shown there is an electron being shot through the tube.

Inside the tube, there are horizontal and vertical plates to guide that one electron to a certain position on the screen.

This is a close up of the tube with the electron.

An oscilloscope can track the electron and also manipulate it. As you can see, the electron is moving compared to the electron shown above that is stationary.

It can also have the electron go faster and faster until...

Only a straight line is visible.

First, we were asked to find the acceleration of the electron using the force equation based on charge and the F = ma equation. The variables that are fixed are charge, mass, and distance. The x-axis velocity is also found to be constant. We were then asked to find the voltage inside the tube.

This is a quick video of a wave generator connected to a speaker. When connected, we were able to hear the noise being generated as well.

This was our set up.

We first set the hertz to 0.096 kHz.

With our small tone emitter.

We also connected the wave generator to the oscilloscope to track the movement of the electron.

We can see slight movement. The whole thing was being powered by two batteries set in series.

A different wave form is being displayed on the oscilloscope.

When the wave generator was set at 96 Hz, we heard a deep low sound but when we set it to square waves, it became louder and sharper and in triangle wave, it sounded like the sine wave but louder. When we changed the frequency of the function generator output, the tone changed and it could go higher and lower depending on the setting. Also, the change in amplitude represents the pitch of the tone.

Sine waves:

Square waves:

Triangle waves:

When we played with the power/illumination controls, the electron became brighter or dimmer. The focus control makes sharpens the line. The most left knob manipulated the electron vertically, the middle knob did nothing, and the x-position knob manipulated the knob horizontally. When we played with the sensitivity controls, it made the electron change the divisions per voltage.

We determined the period of sinusoidal waves to be 10.4 ms. When calculated to find the Hz, it was the same as the one we had on input. The AC/DC setting did not do anything to the display of the oscilloscope. After playing with the frequency dial, multipliers and the time base control on the oscilloscope, the wavelengths were compressed and decompressed.

Unfortunately, our outlet source was a bad source.

Below are examples of DC and AC adaptors that we used in our lab.

With this circuitry, we were able to create Lissajous figures.

Below are both figures being shown. The circle is produced when the wave generator is set at 60 Hz and the more arrow looking figure is shown when the wave generator is set at 30 Hz or 120 Hz.

Next, we were given the Mystery Box challenge. We were asked to find the different relationships between each terminal.

Utilizing the oscilloscope to visually see the relationships, we were able to determine the circuitry inside the box.

The black terminal was the yellow terminal was not connected to anything. But the black terminal was found to be the ground terminal and was connected to everything else. No other terminals were connected to each other.