More love here for a full size wireless KB with full size cursor keys as well as the numeric keypad.
Think big, Apple! Make mine solar powered with backlighting. Thank You!
Just wondering, but if you were using a computer in the dark, like say an iMac, couldn't the light coming out of the screen be enough light to power a solar-powered wireless keyboard?
it's solar power... not artificial-light power![]()
Did I miss something in school? Photons are photons, no? Probably there aren't enough photons from the screen to do much good, but I don't believe that CCFL-emitted photos differ from any other kind.
But maybe you were making a joke.
While photons are, well, photons, they exhibit both properties of particles and waves - since they're the base construct of light. The latter being the important part.
Light (and well, all electromagnetic radiation) comes at different wavelengths. And the different materials that make up photovoltaic cells/photodiodes react to specific wavelengths.
Ideally, solar cells would react best to ultraviolet light which is of a shorter wavelength, and consequently has greater energy allowing for the production of electricity thanks to the photoelectric effect. It's also the reason why they put solar farms out in the middle of nowhere in deserts - lower chance of clouds that would obstruct and filter the UV radiation.
While there are photodiodes that can react to visible light (like for light sensors) it's not practical for use to produce electricity since these are only designed to detect the miniscule amount of electric potential caused from the visible light spectrum.
</science class>
If I'm reading this Sanyo material ("Radiant spectrum of light source and spectral sensitivity of solar cells") correctly, the most important difference is the light level itself, where the LUX values of sunlight are orders of magnitude greater than that standard office levels. This seems to argue for quantitative differences, not qualitative ones.
http://semicon.sanyo.com/en/amorton/feature/index.php
The sensitivity of amorphous cells ("a-Si") maps quite well to white fluorescent radiation, which is of course visible radiation rather than UV.
One tail of the Sanyo a-Si cell extends into the UV range (less than 400) but it's clear that their peak is positioned firmly in the visible range. Sanyo is a main-line manufacturer of cells, so I'd think that the spectral sensitivity of their cells is pretty much the norm.
But perhaps you know otherwise.
Actually, a-Si is used in thin solar film which is an example of a low energy solar cell. Probably due to its reliance on the visible light spectrum. Thin solar films are commonly used on calculators for example - and it easily goes without saying that they don't require a lot of power. As such, it's no surprise that they manufacture a lot of it - there's a lot of calculators out there
Aside from that, it's of no real surprise that an increase in light intensity can increase the potential for an electrical reaction in photocells - cause well, its in increase in energy to cause a reaction.
But, this is really diverging from the topic in this thread lol.