Tuesday, April 11, 2006
I am not satisfied with the amount of inherent noise in my implementation of the interface used for Music for Two Desk Lamps. So in a bid to create a less noisy version, I have today wired up a 1.0V, 0.25A solar module (instead of the previous 0.5V module used). The result? A higher output system, so that less gain has to be used on the audio input.
However, when testing this new model, there was still lots of noise! Hard filtering was used (see picture) to get rid of some of it. After some quick trials, I figured out that the noise was caused by the electrical light bulb in the room where the computer is! Maybe a solid state wave is present in the light energy output of the globe (due to the 50Hz of the AC circuit, perhaps??), and this is then transduced into the audio signal via the solar panel. Maybe different types / brands of lights have different upper harmonics present in their noise, or sound different through other means?
Such a wave was not present when testing the panel in natural sunlight- and this also, of course, gave a much higher output than the electrical lamp. The results of all this are quite promising.