Lab 12

Blog sheet Week 12:

This week’s blog sheet will be individual but you will post it on your group blog.

Your individual Rube Goldberg (RG) setup should satisfy the following:

1.       Use at least 2 of the following components:

a.       Transistor

b.       OPAMP

c.       Relay

d.       Temperature sensor

e.       Photo sensor

f.        Motor

g.       Display

h.       Strain gauge

i.         Speaker

j.         Microphone

k.       Solar panel

2.       Use a new circuit: It can be a modification to one of our lab circuits.

3.       Let your system complete its task in no shorter than 10 seconds.

4.       Make sure you are compatible with your preceding and following RG stage.

Your blog sheet 12 tasks: Tyler D.

1.       Provide the computer drawing for your individual RG setup.

Breadboard Car

2.       Explain your setup.
        The first step I took was to make the frame of the car and wheels using the components similar to LEGO pieces. Then I mounted a breadboard to the top of the frame as seen in figure below.  The next step was to power the car and the first video below displays the car moving along the table top. After this was complete I made the timer circuit on a separate breadboard to make sure I could get it to function properly. As you can see in the second video I have the timer set up so when power is applied to it an LED lights up for around 8-10 seconds before it shuts off.
       The next step was to apply the pressure sensor to the circuit so that when pressure is applied the timer would start and then after a given period of time it would shut off. Unfortunately you can see in the third video that the pressure sensor fails to activate the circuit so I will be trouble shooting this problem on Monday.
        The overall goal is to have Vince drop an object on the pressure sensor of the car and then it turn on and roll for 10 seconds at a slow speed and then stop over Tyler's pressure sensor to continue the RB circuit.

3.       Provide photos of the circuit and setup.

Initial Breadboard car setup

Timer/Shutoff Circuit

4.       Provide at least 2 videos of your setup in action, one being a failed attempt.

Breadboard Car in action

Timer Circuit powering LED for 8 seconds

Failed Attempt using Pressure Senor to Trigger Timer

5.       What failures did you have? How did you overcome them?
       The failures that I had was the unknown reason for the pressure sensor to not activate the circuit. This is the reason I did not add the pressure sensor inputs going to the 555 timer. I did not want to add them in the schematic if it did not work.  I will update the schematic once I get it to work. I also have not added the 555 timer circuit to the breadboard on the car because I was going to make sure I can get everything to work more spread out on a larger breadboard. Once I can get the pressure sensor to trigger the timer I will also replace the LED part of the circuit and add the amplifier which will connect to the motor. I did know this was going to work and be implemented so I added it to the schematic.

      Your blog sheet 12 tasks:  Tyler L.

1.       Provide the computer drawing for your individual RG setup.

Computer drawing of my circuit

2.       Explain your setup.

                   In my setup I will be using a 10V power source which runs through a pressure sensor to an non-inverting amplifier using a 1.4 kilo ohm resistor as R2 and a 273 ohm resistor as R1.  The non-inverting amplifier runs to a motor which has a string taped to it. 
                  When the pressure sensor is triggered the motor runs slowly, pulling on the string which is tied to a catapult using rubber bands as a source of tension.  When the catapult reaches around a 90 degree angle the string will slip off a smooth metal rod and launch the ping pong ball sitting in the basket.

3.       Provide photos of the circuit and setup.

My catapult

A previous idea for my circuit with a smaller motor

A previous idea for my circuit with a smaller motor

My current circuit set up

4.       Provide at least 2 videos of your setup in action, one being a failed attempt.

A video showing my circuit with the motor attached.

                                          A video showing my circuit without the motor.

                                           A video demonstrating how my catapult will work.

5.       What failures did you have? How did you overcome them?
                The greatest issue I am facing is that the OpAmp and output are not what I'm expecting.  When I do not have the motor grounded I read an output of 7 volts, which is sufficient to run the motor.  However when I ground the motor I read an output of 1 volt which is not sufficient to run the motor, and without the motor grounded it won't run anyways.  I am not sure why this is occurring and it is a continuing source of frustration.