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Spreadsheet Oscilloscope |
It is not always easy for students to visualize the concepts of "amplitude" and "frequency".
For example, when using an oscilloscope changing the "amplitude" of a test signal changes its size on the Y-axis, or height. The Y-axis (vertical axis) is conventionally used to display voltage.
"Frequency" is a measure of how often events occur. Therefore a higher frequency allows less time for each event (more events in a second means each event lasts less time). Students learn the relationship T = 1/f. Since in conventional use the X-axis (horizontal axis) of an oscilloscope depicts time, a higher frequency actually squeezes the cycles closer together.
Sine waves are probably the most common signals used for AC circuit testing. The equation v = V sin(2πft) helps us recognize that both the peak voltage (V) and the frequency (f) are values which will influence v as a function of time.
As an exercise both in displaying this relationship and in learning additional features of electronic spreadsheets, a Microsoft Excel spreadsheet has been built in which the values of V and f are adjustable. A simulated oscilloscope display will then change to depict the new sine wave.
No, the screen clip above is not active. To test this spreadsheet on your computer, right-click here and choose "Save Link As" or "Save Target As". Un-zip the resulting file and open it in Excel. If you prefer a version which is already decompressed, try this one. How did it work for you? If you have ideas for enhancements to this experiment, please contact me at the address below. Thanks!
