Greg’s “cameleon lamp”, he writes –
Concept: To design a light that mimics a color if shown to it. Design: lamp driver. LEDs are very efficient as they only emit one frequency of light, and because of this the light produced could be perceived as flat and lifeless. Instead i used tungsten bulbs because unlike LEDs they aren’t flat and lifeless. Because the Arduino cannot provide enough current to power a tungsten bulb without damaging the Arduino chip, I had to use transistors to turn a separate power source on to power the bulbs. This also meant that the lamp wouldn’t draw too much current from the laptop. To do this i connected the pwm pins to base of the transistors, and grounded the transistors to the Arduino’s ground in series with diodes to prevent current flowing back through the tungsten bulbs from the Arduino. Because i used the pwm pins i could dim the bulbs the same way one can dim LEDs in the Arduino code.colour sensor. Because I wanted the lamp to detect colors and mimic them, I prototyped a simple color sensor.
Making furniture interactive – The cameleon lamp Link.
6 thoughts on “Making furniture interactive – The cameleon lamp”
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Do I understand correctly that he uses incandescent bulbs to get broad light spectra, but then filters them back down to single wavelengths with gels so he can re-mix them? Seems a little silly to me.
What type of transistors would you use in a project like this? I understand some of the fundamentals of transistors, but I always have difficulty in figuring out how to choose appropriate ones, especially since many are apparently interchangeable. Any good links for the non-EE tinkerer? Thanks!
Borgie – for driving high-power incandescent lights, you need a high power transistor, maybe even a power Darlington. Typical devices include the TIP41, 2N3055…basically, anything in a T0220 package ;)
Read the datasheets, check out the ‘Hfe’ and ‘Ic(max)’ values (for this job Ic(max) should be at least 250mA)
AP – Very true…does seem a bit odd going there-and-back-and-there-again. Perhaps we could recommend a high power LED or two? How about the Luxeons?
http://www.luxeonstar.com/sub_category.php?id=1431&link_str=1431