Sunday, March 12, 2017

Blog 8 Group 1

Draw and explain a Rube Goldberg design that will include the following components:
* Digital
* Motor
* Relay
* Opamp
* Temperature sensor
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.

 Figure #1: Before the circuit begins, the blue LED shows that the relay has yet to be switched so there hasn't been enough power supplied to the temperature sensor/amplifier.
 Figure #2: After heat is supplied to the temperature sensor, there is enough power that switches the relay over to the other side triggering the rest of the circuit.  Between the number 4-9 on digital display causes the motor to be activated.
 Figure #3: Once the motor is activated it takes two rotations to cause enough line to be pulled to cause the wheels to be pulled onto the force sensor causing a resistance that would trigger another part of a circuit.
Figure #4: Shows the whole circuit setup before extra heat is added to the temperature sensor.
Video #1: Shows how the circuit works as heat is applied to the temperature sensor.

Issues Faced:Easily the biggest issue that we faced was trying to get the temperature sensor to output the correct value to the OPAMP to cause the relay to switch.  We had to adjust the resistors multiple times, and also interchanged out our OPAMP to a larger one cause the first one couldnt output enough power.

We also had an issue with the relay.  It took us a while to realize which inputs go into the relay.  We were unknowingly misusing the pins on the relay.  Once we figured that out and adjusted the gain for the OPAMP the circuit worked the way we wanted it too.

Figure 1: Rube Goldberg circuit schematic 


  1. nice job this week. we had a very similar circuit except our digital display only showed number 7, the number group we are, rather than running a count 1-9. We had a similar issue with the temperature sensor as our first one was broken and it took us a while to realize thats what the issue was. also our amplifier wasnt the correct one and the relay had difficulty using the signal

    1. Yes we didn't realize that the opamp didnt not have enough current for the surge required to switch the relay

  2. I like this circuit. You included the motor and OPAMP early on which I think was smart. I didn't do that and it gave me trouble. It is also good that you did that because the options of expansion are endless with the way you have the circuit right now. Good job!

    1. Yes, good observation alec we 100% did this on purpose as we realized early that this would be the most difficult part of our circuit and by placing it first made it the easiest to troubleshoot.

  3. I really like how you had the blue light as on which shows that the circuit hasn't received enough power to turn on the relay. That's awesome! Also it's really cooler that you had the count set from 4-9 which would start the car. Really high tech and cool! I think you guys did a great job on the circuit but I think it would be cool to maybe implement the circuit onto the car instead of the string, so the car can move on its own without the string :) great job though circuit looks very good..

    1. Thanks Drake we will keep that in mind

  4. I like how easy it should be for the group after you to begin their rube goldberg, as long as they can incorporate a force sensor.

    We also had issues with the temp sensor, they seem very finicky.

  5. We also had issues with the temp sensor. We found that no matter how much heat we applied, we had issues supplying voltage to other apparatus from the temp sensor. We found that the most a temp sensor could provide was 1 volt when being applied 5 V. We solved this with an opamp and a large voltage going to the opamp to get the voltage transmitted to a more usable value.

  6. I see the motor spinning but not the car and the pressure sensor. Otherwise, good job.