re-cyclelight is a regenerative brake-light system by Alexander Kozovski and Becky Kazansky.
Featured in Best Student Green Designs on Inhabitat
Bikes are a part of our daily lives. Sustainability is a concept we hear about so much that its meaning has become diluted. Alex and I set out to make a small intervention in our daily lives — which involve bicycles — in order to see what that big concept could mean for us.
We decided to create a bike lighting system powered by the kinetic energy from braking the bike. Regenerative breaking isn’t a new thing: Scandinavian train systems have generated a surplus for local electrical grids for a hundred years with a system that utilizes the friction produced from breaking.
Dynamo systems for bikes often require an installation into the hub, generate power with each pedaling cycle, and cause an additional amount resistance for the rider. We wanted to make a system as non-invasive as possible; something you could ideally clip into the pre-existing setup on your bike.
To use the brake calipers to drive generators to produce power.
Discreet unit of 2 geared motors per caliper, connected to an array of LEDs.
Activating the brake(pressing on the lever) puts the motor shaft to the wheel(tire). The friction turns the motors, thereby generating power to light the LEDs.
*The motors are placed on the caliper in front of the brake pads.
This is done for safety as engineering redundancy: If motors fail for any reason, the bike reverts to the default mechanism of the brake caliper.
Final Design Implementation:
Once installed, we found that each motor outputs at its highest revolutions approx 12V at 1 : 24 gear ratio; more than enough to power our circuit positioned under the seat.
We like that our device is only actuated when needed. It requires very little effort from the user, as it takes advantage of lost energy that would normally be converted to heat by friction.A standard dynamo design would affect the user during the entirety of the ride, requiring extra effort to generate power.
This design, allows both the control/actuation and the power generation to happen at the same moment, thereby not requiring a separate control mechanism (i.e switch) to power the circuit. This makes for both robust/efficient minimum constraint design.
The mini gear head motors we used were well sized for the application (1.26″ x 0.63″ x 0.63), but the output shaft was very delicate 0.275″-long, 3 mm-diameter . The assembly process required us to remove the output gear from the shaft of the motor enough times that the pin holding it in place wore down, causing it to wobble. In the end, we used just one motor to generate power to our “STOP” LEDs.
We wish to use both motors as a pair to generate more power for other applications. Adding capacitance can expand the function of the lights beyond moments that the breaks are actuated.
One idea is to utilize an LED projector (paired to a smart phone) to visually provide directions in the form of projected directional arrows and serve as a headlight to light the way at night.
Posted: May 12th, 2011
Categories: Sustainable Energy
Tags: Nature of Code
Comments: 1 Comment
A game not for a rainy day
SUNTRIAL was featured at the 2011 Come Out and Play Festival on Governor’s Island.
SunTrial is a fast-paced strategy game based around light collection. The game is played on a field with 5 checkpoints and uses custom solar-powered game pieces (Sun Disks). The Sun Disks allow teams to collect sunlight and easily track their scores. Two teams compete by exposing their side of the Sun Disk to collect light. Players must be careful, however! Too much sun exposure causes the dial on the disk to reset, costing the teams valuable points.
Rules of the Game
Objective: Two teams of light collectors, Orange and Blue, fight to get the most points across 5 sun disks by exposing them to sunlight.
5 checkpoints on a field arranged in an x, with a disk at each checkpoint.
There are 8 players, 4 on each team.
Each game round is timed.
Time is kept by a referee.
Each disk has an Orange and Blue side.
Each side has a solar panel and a score-keeping dial.
The sun-facing side collects light, which causes the dial to advance.
To change your score, expose your side of the disk to the sun.
The dial ticks up to 6, then goes back down, so watch out!
Check on all your disks by running around the playing field.
There is a tagging zone around each checkpoint.
You can tag a player on the opposite team while they are in the tagging zone in order to stop them from interfering with the disk.
When you tag an opposing player, you both have to leave the tagging zone!
You can’t guard the disks.
You can’t visit the same checkpoint twice in a row.
At the end of gameplay, the number on your dial is your point value for the disk.
Add up the total on all the disks for your final score.
putting the game pieces together:
Sundisk is a competitive team-based game about capturing light.
Game pieces: solar-powered disks spread on the ground.
Each disk has two functional sides, with counters (powered with motors that receive their power from sunlight) dynamically displaying the teams’ scores. The goal is to get your counter to move from 1-5, but not past 5. If it moves past 5, it resets to 1.
Side A powers Team 1′s counter, Side B powers Team 2′s counter.
Capturing enough light triggers the motor to turn a bit and increment the team’s counter.
Players need to run around and flip disks over to catch light advantageously for their team.
The team with the most points after a period of play will win the game!
Strategy enters into the game because each disk will have a solar panel on each side. Team counts can go up to a point before they start going down again. Players will have to determine what will be more beneficial for their team: flip the disk so that their team is gathering light (and hopefully gaining points) or flip the disk so that their opponents are gathering light (and hopefully losing points after passing the threshold).
Metrics for success:
Becky and I have fairly simple metrics for success:
* Do our disks function? The circuitry is just a simple miller engine, so we want to build something that won’t break when roughly flipped. If our disks don’t function accurately and reliably, then we don’t have a successful game!
* Are our disks durable? Since we anticipate reckless flipping of our disks we need to carefully consider scratching and durability. Excessive scratching on the surface could affect how much light reaches the solar cells, so it is especially important that we choose durable, scratch resistant materials.
* Are the disks aesthetically appealing? Since the circuitry is fairly simple we think the look and feel of the disks should be exceptional!
* Is the game simple enough for pickup games? Games with a lot of rules have a higher level on entry for casual players. We need to strike a balance between simplicity and clear, challenging, compelling rules.
* Is the game fun? Perhaps most importantly, we want this game to be fun! If it’s not fun, then we will have completely missed the mark.
We are as of yet unsure what materials we will specifically use for the construction of the disks, but we know we are going to make a Miller Engine as outlined by Solarbotics. Ideally we’d like to use a dual-shaft motors inside each disk (so we can display team points on both sides of the disk), something like this motor.
Here is a list of possible parts for the miller engine:
* 3904 NPN Transistor
* TC54 Voltage Detector
* 4700 uF Capacitor and 4.7 uF Capacitor
* Dual Shaft Motor
* Solar Cell
* Shottky Diode
BEAM BOT DOCUMENTATION: