## Saturday, March 11, 2017

### Lab 8

Draw and explain a Rube Goldberg design that will include the following components:
* Digital
* Motor
* Relay
* Opamp
* Temperature sensor
* LED
The setup should be considered to last 30 seconds.
Make sure to include enough photos, videos, and explanations for each “transition” or step. Explain your circuits. Put at least 2 issues/problems/struggles you faced during the project.

Video: Explanation of entire circuit and how it should work

Video: Final Rube Goldberg set up
Problems:
As you can see when watching our final video, we only managed to get half of our set up to work. The heat sensor did not function as it was suppose to and ended up giving a negative voltage reading, and at other times, changing nothing in the circuit, gave a positive voltage. We tried changing out the temperature sensor and nothing changed, we then added a third power source of the same voltage to see if that would help at all, but unfortunately it did not.

Another problem we had was getting enough pressure on the pressure sensor to make the led light up. We noticed that we would need a much heavier object to land on the sensor than the small dominoes, so we made our own thinking it would be heavy enough. It did light up the led, but just barely and had to be positioned just right to fall on the sensor or it would hit the table or breadboard and not function.

Circuit Drawing:

Figure: Circuit Drawing

For this project, the diagram shows 2 separate circuits involved in completing the process: one involving just an LED, a force sensing resistor and a voltage source, and the other involving several components. The aforementioned complex circuit involves a temperature sensor, which will increase voltage through an opamp in order to trigger the relay. this allows current to flow to the 555 timer, which triggers it to start oscillating. the output of the timer is connected to the decimal counter so that it counts after the timer has been triggered. With the lowest and highest significance outputs connected to an AND gate, the output of this gate should be positive at 9 seconds. this positive output should then trigger the motor to turn. In our actual circuit, as seen above, this causes dominoes to fall, which should then theoretically trigger the pressure sensor in the other circuit to turn the LED on.

1. I really like your guys setup. it was unique how you used the dominoes as a middle section of your circuit. I also really liked how you used the and gate so the motor only triggered when it was at #9. We had issues with our temperature sensor as well, it took as a while to figure out the whole setup.

1. The temperature sensor definitely caused some complications, but this will hopefully change with experience. I am glad you liked our set-up.

2. i really like your project and how did use all the component and i like how did use the and gate to make the motor works when the seven sigma display reach #9

3. I like how did you setup you project especially how to connect the sigma with and gate when it reach specific number. I think you need to add more pictures for all components you used.
Good job.

1. Thank you for your feedback, and I see what you mean about the pictures, so we will keep that in mind.

4. i like that you used the digital component that sorted signals on significance (i cant remember what its called). also ive noticed a lot of groups had issues with the temperature sensors, including my own group. Do you have any ideas why this was? we also had issues with the pressure sensor resistor, it was making our voltage negative which was causing issues with our relay. nice job this week!

1. My only theory about the temperature sensor is that the connections to other components of the circuit like voltage sources and capacitors may have contributed to widely varied readings. This may also be the cause of the issue with the pressure sensor, but I am uncertain on both counts.

5. WOW! I think you did a great job on your Rube Goldberg circuit :) I really like how you had the counter go up to 9 and once the counter hit 9 it started the fan which knocked over the dominoes and triggered the pressure sensor. We had the same problem with the pressure sensor as well as we had troubles with having enough pressure to turn on our counter. I think your circuit is also super detailed and it looks really awesome!

6. Did you guys try testing your temperature sensor isolated from the rest of circuit? I am interested as to why your output was negative because if compared to ground that seems nearly impossible unless the input voltage is negative or of course the component is broken and from what I understand you guys tested that.. Would like to know how you guys ultimately fixed this problem!

7. The video that you posted explaining your circuit went into great detail and was an excellent addition to the blog. I am sorry that your circuit did not work as you had wished, ours did not either. I am not sure how strict Kaya was on the 30 second time limit, but you may want to consider something that takes a little bit longer for the next Rube Goldberg circuit. Overall, good descriptions, clever idea, and good blog.

8. Nice job trying to explain how your circuit would work in theory, in the future you wouldn't necessarily have to use the decimal counter, along with the Logic gates, unless of course you were actually timing something. We were able to alternatively use power through the 7 segment display with a more manual method for our RG. Sorry your circuit didn't work, it took a lot of time to get ours to work properly.

9. Good explanation of your problems.