The discussion revolves around the calculation of the difference in divisions between two oscilloscope traces represented by the equations V1 = 10cos(10^4t) and V2 = 5cos(10^4t + pi/3). Participants explore the implications of amplitude and phase shift on the oscilloscope display, focusing on how these factors affect the visual representation of the signals over a specified time base setting.
Participants generally agree on the significance of amplitude and phase shift but have differing interpretations regarding the relationship of pi/3 to the total period and the resulting number of divisions. The discussion remains unresolved regarding the exact calculation of the divisions based on the phase shift.
There are limitations in the discussion regarding the assumptions made about the relationship between phase shift and period, as well as the calculations of divisions based on these interpretations. The dependence on definitions of phase and period is also noted.
eehelp150 said:Would the difference between 10cos and 5cos add a factor of 2 or 1/2 to the # of divisions?
You are making this difficult for yourself if you are attempting to answer this question without first sketching how the oscilloscope is displaying these two signals.eehelp150 said:Would the difference between 10cos and 5cos add a factor of 2 or 1/2 to the # of divisions?
a. Same frequencyCWatters said:No. The 10 and 5 give you the amplitude. For example at a peak, when cos(...) =1, one waveform has the value 10 and the other 5.
Hints:
a) Both waveforms have a common 104t term. What does that mean?
b) One also has another term pi/3. What does that represent?
B would shift the graph over to the right by pi/3?CWatters said:Correct.
Which of a and b shifts the trace left to right along the time axis relative to the other?
So how many divisions will these two traces differ?CWatters said:Correct.
Although I think V2 would be shifted left relative to V1.
1/3 of the period?gneill said:You have calculated the period of the signals (the time for one cycle). How much of one period does the phase angle represent? What is it in milliseconds?
Can you show how you determined the 1/3 value? Is pi/3 really 1/3 of a full circle?eehelp150 said:1/3 of the period?
0.209 ms?
Pi/3 is 1/6 of the total period, so would it be 0.105ms or 1.05 divisions?gneill said:Can you show how you determined the 1/3 value? Is pi/3 really 1/3 of a full circle?
That looks better!eehelp150 said:Pi/3 is 1/6 of the total period, so would it be 0.105ms or 1.05 divisions?