User:Batmaneatsgrass/project 1

My Instructor's user page which points to this.

Project 1 : Light Switch Turner

Week1 Narrative
During week one, I looked for various similar projects online to see if we can use any existing ideas - basically, we want a robot that turns the lights off after it receives a ranged signal. It would also have to be something fully made, so the user wouldn't have to mess with the wiring of his/her house. It would have to be easily attachable to the wall.


 * One idea I found was to have a robot that moves at the sound of a clap. A drawback is that it would turn the light on/off whenever any sound would be made, including talking, which would be annoying. Since the concentration of the project is "usefulness to lazy people" rather than "obnoxiousness" the clapper idea stopped here.
 * Another idea is to have a robot arm that moves the switch. While it would be visually appealing, the arm would require a great amount of power and would likely not be easily mountable on a wall. I did various searches on google like "types of robot arms" and "articulated robot kit" but found nothing on a smaller scale. I decided that even a small multi-jointed arm would be too difficult for a beginner-level group of individuals with no electronics experience to make.
 * The next idea was to make a one-jointed robot arm, or to simply have a stick that connects to a motor which then turns and causes the stick to hit and turn the down or up. I decided to go with this idea and, after looking at pictures of different motors, drew out how the motor and stick would be attached and how they would function together.

Week2 Narrative
''' For week two, my job was to figure out what type of motor is needed to turn a toggle light switch back and forth. To figure out which motor was needed, I first went on a DC Motors tutorial site and found out what determined how powerful a motor was.

Voltage
 * Difference in charge between two points
 * Non-polarized means motor can reverse voltage
 * Most DC Motors operate between 6V and 12V
 * More voltage means more torque
 * Voltage rating shows motor is most efficient running at that voltage. 6V motor needs a 6V battery

Current
 * Rate at which charge is flowing
 * Too little and motor won't work, too much and it might break
 * When getting a motor, pay attention to operating current, which is how much current a motor draws under normal torque

Resistance
 * A material's tendency to resist current
 * Material heats up when resisting

To reverse direction, a motor must reverse voltage, which is more difficult for a DC motor to do than an AC motor. Here I decided that I need to obtain a stepper motor for this project.

Week3 Narrative
''' During this week, I had to find out how much force it takes to turn off a toggle light switch. In order to do that, I came up with an experiment. I would tie a string with a loop on one end to the switch and keep hanging weights until the switch turned off. Then, I would record the total mass in grams and later convert it. I did this with three switches to reduce error and the results were different from what I expected. Two of the switches turned off when 700 grams were hung from them and one switch turned off when 650 grams were hung from it.

Week4 Narrative
''' Our class started late on our first project so we didn't get a week 4.