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 arenâ€™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 wouldnâ€™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 Arduinoâ€™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”
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?
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