Students: Kevin Kim, Shiori Sasaki, Simon Khuvis
Our proposal aims to produce an ethereal atmosphere through which visitors may navigate, disturbing sensors embedded in the installation, causing the optical landscape to change. Our prototype uses stored solar energy (means to be determined) to power arrays of LED lights connected to a circuit that can modulate both the amplitude of the light, and the speed at which the amplitude changes, to produce a kind of “breathing” effect. The LED lights are strung through transparent hoses which will be suspended overhead, like the tentacles of a jellyfish, for example.
Testing the ability of the newly purchased photovoltaic (PV)cell to power the LED at a constant level. The PV charged a capacitor bank through a diode, to
prevent discharge in the wrong direction, and when a button switch was depressed, the chargestored in the capacitor bank would flow through a driving circuit for an LED. Completely charged, this allowed roughly one second of full-brightness operation. A major shortcoming of this method was that the driving circuit, which kept the LED brightness constant, was quite inefficient, and drew too much power on its own, leaving little for the light. Componentsincluded a 4.5V, 0.5W photovoltaic cell from Radio Shack, and standard parts (breadboard, signal diode, 2.5V shunt regulator, 2N3904 NPN BJT transistor, miscellaneous resistors and yellow LED).
One of the main reasons we had settled on solar power as our method of choice for the exhibition is its reliability. In other words, we wanted to have a feasible source of power so that we could focus on the aesthetic and social components of the light itself. To that end, and now equipped with the knowledge that the PV cell could, in fact, power the LED, we set about building a new prototype. Here we wanted to demonstrate the dynamic nature of the light itself, in relation to the social context in which it is located. A bicolor LED was used, and the two colors—green and yellow—were programmed to fade into one another slowly using a digital circuit, an effect reminiscent of slow, gradual breathing, and inspiring the same kind of calm. It was also proposed that a sensor could be used to detect the presence of people interacting with the light, and change the behavior (frequency of the change, etc.) accordingly.Components included a battery pack (hacked calculator) and standard parts from the EE labs (breadboard, signal diodes, two 7555 timer ICs, 4030 quad XOR gates IC, and a yellow-green bicolor LED).
At this point, we felt that it was important to combine the off-grid elements with a perfected version of the fading circuit. We switched from the digital system in the last
prototype, back to analog, and purchased a bright white LED. We also put the PV cell back but we did not attempt to store the energy from the panel and release it later. Components included a
glass jar, the PV cell from the first prototype, a bright white LED purchased from Radio Shack, and standard components from the lab (7555 timer IC, diodes, op amp IC, 2N3904 transistor, miscellaneous capacitors and resistors).
This design allowed for interaction with the exhibition in much the same way as the curtain, if so desired, and also allowed for a social aspect, in that the patterns of the lights in the curtain could change based on the number of people walking though the curtain together. If we fabricated multiple “curtains” to be installed throughout the block, the block would appear to be glowing, breathing, oscillating, and so on, as attendees of the event passed through it. Though we initially imagined the curtain as a linear element, we later discussed the possibility of installing the light-tube modules in more of a “field” configuration.