Friday, April 7, 2017

Blog Report Week 12 - Liam

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

1. Use at least 5 of the following components:

a.) Transistor
b.) Op-Amp
c.) Relay
d.) Temperature sensor

e.) Photosensor
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 week 12 tasks:

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

Original Schematic: design layout of my RG circuit.

Updated Schematic: design was updated because it was not complex enough, added dominoes.

2. Explain your setup.
  • In my Rube Goldberg circuit, I start off with a 5V power source connected to a temperature sensor. 
  • The is hooked up to a LM324 Non-Inverting Operational Amplifier, the voltage gain       [ Av = 1 + (2000Ω / 274Ω) ] = 8.3V. The op-amp requires a voltage supply equal or greater than the gain, so it’s (V+) is 10V. 
  • The output from the Op-Amp then flows into (pin 2) of a relay, by heating up the temperature sensor it will trigger the relay within a few seconds. (Pin 1) has a 5V "fixed" power source to ensure that enough voltage and current is supplied to components after the relay. 
  • Once the relay triggers to (pin 4), the output will go to a 555 timer which will create a step-function frequency or better known as a clock rate, which will power a motor up to a motor (mechanical component). 
  • Since the motor’s power supply is impulsive, the attached arm must be set vertically so that gravity’s potential energy along can combine with the rotation speed to build enough momentum to overcome the initial resistance and stresses the motor faces when running. 
  • Once the motor starts to spin, it begins flicking/flipping a strain gauge (you can see the signal output generated by this on the oscilloscope shown in video 2), which leads into the next circuit/portion of the Rube Goldberg.

3. Provide photos of the circuit and setup.

Photo 1: Overview of entire Rube Goldberg setup.

Photo 2: A closer look at the components wiring.

Photo 3: A depth of view close-up on the circuits components.

Photo 4: A look at the mechanical component (Motor)
and Strain Gauge to next portion of circuit.

4. Provide at least 2 videos of your setup in action (parts or whole), at least one being a failed attempt.

Video 1: Rube Goldberg Circuit - Test Failure

Video 2: Rube Goldberg Circuit - Successful Completion

5. What failures did you have? How did you overcome them?
  • I struggled to get the relay to work properly, apparently using the 5V power source for both pins 2 and 1 will create an issue where the relay repeatedly turns on and off multiple times per second because the amount of voltage being drawn from past the relay creates an insufficient amount to continuously power the relay. I was able to solve this by using a separate 5V "fixed power source.

  • Hooking up the 555 timer to a motor works fine, except for when there is a load or opposing force on the motor, since its power supply is impulsive and not constant flow it created a problem where the weight of the arm was too much resistance for the motor to initially overcome. I was able to solve this by setting the arm vertically each time I ran my Rube Goldberg. 


  1. I like the complication in the circuit and drawing is nice. I would like to see a better drawing of the mechanical part. Also, your mechanical part needs to be more complicated.

  2. I like your mechanical part a lot. Using that motor to activate an arm to work the strain gauge was a really cool design. How do you plan on heating the temp sensor from the previous circuit? Was it hard to get those components of the circuit to work together? I had issues creating my circuits relay power as well.

  3. I like you project, and I have similar issue with the relay, you have to give 6V or more to pin 1 to start the the relay. I think you can add an other mechanical part causes by spinning arm or any different part. I like that you use the temperature sensor which was complex for us.
    Good job

  4. Your project is well done. My circuit is pretty similar, the difference is that I used a photo sensor in order to change the voltage necessary to switch the relay. The mechanical part could be somewhat more complicated, but Im excited to see how it all turns out at the end.