Picture of the day

Could DSP produce some sort of modern art on some occasion ?

harmanics

Do you want to reproduce that ? Well, here is the recipe …

Get a function generator and set the signal pattern to ramp, sweep frequencies from 80 to 90 Hz with 0.1 Hz steps every second. Connect the output to PlainDSP* and starting from the example scripts write you own which will: look for the more intense signal in the 50 to 100 Hz window, interpolate the peak apex, search for target peaks corresponding to to the 2d up to the 10th harmonics. Plot the computed apexes for every scan and you will get this fancy drawing !

Converting a ramp signal to a frequency spectrum is a very convenient way of generating a whole series of harmonics (see spectrum sample below):

harmonics

while for example, a square signal will produce only odd levels of harmonics (see spectrum sample below) !

harmonics_b

Once again, graphics allow a quick first pass data analysis and show that the device operates very nicely (see this other example in previous post).

* Some tweaking might be necessary depending upon the input signal, please contact me for specific applications.

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