TA tuning the X-Y position and the focus of the beam with a screwdriver.
Inside is a power supply powering an electron gun. The front of the tube is coated with a material called "aquadog". between the back and front of the tube, there is a large potential which excites and accelerates the electron to fire from the negatively charged rear to the positively charged front.
The phosphor front then emits light. Similar to tuning but instead of a screwdriver, the two leads X and Y of the oscilloscopes will apply whatever voltage applied to them onto the X and Y plates, causing the beam to move on the screen.
Our first experiment is to try the tap key and using it to measure the voltage of the battery. First, we hooked up the tap key to the battery and oscilloscope. Then we measured the battery to have a potential of 1V. Next, we calibrated the signal on the oscilloscope to be at 0 (center) while leaving the tap key was unpressed. When the tap key was then pressed the line moved up one square, showing that 1V DC was going through.
Tap key not pressed (left), line jumps when tap key pressed (right)
The signal jumping when the tap key was pressed when the oscilloscope was set at a slower frequency so that this can be easily seen as the tap key was being repeatedly pressed. Rudy clearly demonstrated this with his Morse code ability S.O.S...
Next, we used the oscilloscope with a frequency generator to analyze the sine/cosine waves of each generated function/frequency.
Sawtooth wave (left) and a Square wave (right) function
For the square wave, the vertical line portion is a discontinuity in the graph therefore not visible oscilloscope. In the sawtooth wave, the wave goes from a positive slope, hits a maximum and then goes to a negative slope until it hits a minimum and repeats.
The sine wave was completely smooth and resembles just like the sine function.
With the frequency generator at 96.000 Hz, we connected a speaker to hear the various different sounds of these waves. The sine wave had a low bass, the sawtooth wave had a sound with least intensity, while the square wave with the highest gain yet most distorted.
As we experimented with the various controls on the function generator and found that adjusting the frequency changed the pitch of the sound produced while changing the amplitude affected the loudness of the sound produced.
.jpg)
Next, we observed the oscilloscope has the "Time/Div" set at 2 ms. Knowing this, we can determine the period of a sine wave by comparing the output of the 96.000 Hz wave from the function generator. As it turned out, the theoretical period from the function generator is T= 1/ (96.000 Hz) = 0.010.From the oscilloscope, we measured (from where the curve first hit the x-axis to when it completed a cycle) the length of 6.5 squares. From our settings on the oscilloscope, each square is 2 ms = 0.002 s. We can compute the experimental period as follows: T = (6.5 squares)(0.002 s) = 0.013.
The percent error was 30%, however for the purpose of the experiment, we can consider it acceptable.
We then measured the noise of DC current for several household power adapters to determine the quality of its output signals/power.
Cheap power supply of a phone charger from Alice's table with much inconsistency!! DON'T CHARGE AN ANDRID/WINDOWS PHONE WITH THIS.... (iPhones OK since they're crap anyway)
Comparing to the "grey" DC power source, the oscilloscope found the source to be cleaner. We really needed to turn the sensitivity way up to see the noise results.
.jpg)
Our power supply is pretty consistent in terms of noise although Made in China
Next, we were given a mystery box that has 5 unlabeled connections. Our goal was to use the oscilloscope to figure out what's going on between these.terminals as we have no idea of the configuration inside. Using the two connectors of the oscilloscope, we predicted the total possible number of configurations are 5 nCr 2 = 10 possibilities.
We were to determine the internal configuration of this "mystery box"
No comments:
Post a Comment