Wednesday, April 5, 2017

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:

Moaad's Rube Goldberg
1.       Provide the computer drawing for your individual RG setup.  

Photo 1.1 Circuit set up

2.       Explain your setup.
The circuit will start with a force sensing resistor that will get some load from my partner then the output is going to the Amplifier that is connected to the 555 timer which gives the output to 74192 which send to the 7447. The 7 segment display will start counting. When it reach to 9 the motor will turn in by the AND gate which is prepared to. The motor will start the race by hitting a car after bombing a balloon. The car will go through a racetrack. I am ready to change the end if it doesn't help the next person. 

3.       Provide photos of the circuit and setup.

Photo 3.1 Force sensing resistor. 

Photo 3.2 amplifier.

Photo 3.3 555-Timer and 74192.

Photo 3.4 The 7-segment display, the AND gate, and the motor.

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

Video 4.1 The first failed attempt.

5.       What failures did you have? How did you overcome them?  

My biggest struggle in the class is when resistors touching each other. I take an hour trying to find the problem and then finally it was just two resistor touching each other. 
Other two failures and I'm still trying to overcome them are make 7-segment display counts and get enough current to the motor. 

Daniel's Rube Goldberg
2.       Explain your setup.

The photocell will be used in the rube goldberg circuit to switch on the 555 timer using a transistor. When the photocell is covered the voltage at the base of the transistor is about .2 V and when uncovered it is about 1V. The transistor powers the 555 timer to start counting and will count up to 9. When the 7 segment display shows 5 an and gate will switch on for pins A and C which is the binary number 0101. The and gate will power a small motor that knocks the domino off of the other photocell.
Another photocell resistor limits voltage to the op amp to about .8V when the photocell is covered. When uncovered the op amp puts out about 6.6V, which should be enough to switch the relay, the relay is hooked up to a motor that swings a wire around to knock a ball over to knock over some dominoes.

3.       Provide photos of the circuit and setup.

Displaying 20170405_204719.jpg

Image 3.1 Op Amp and photocell resistor

Displaying 20170405_145822.jpg

Image 3.2 Relay and transistor with Op Amp

Displaying 20170405_204712.jpg

Image 3.3 7 Segment Display and BCD(7447)

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

Video 4.1 Showing a failure of Rube Goldberg

Video 4.2 A Part of the Rube Goldberg circuit

5.       What failures did you have? How did you overcome them?  

I had a faulty Op Amp and also a faulty portion of my breadboard at the same time in the same location. This consumed a lot of time attempting to change out Op Amp with good ones with no success. I then put the original Op Amp back in on another spot on the breadboard and with trial and error I found that both the Op Amp and a portion of the breadboard was malfunctioning.
I Also had troubles with the 7 segment display resistors touching each other, but with some careful bending they were not touching anymore. 
The relay proved troublesome in that the voltage had to be around 6-7 volts for the coil to energize and switch the relay. This was achieved by setting the gain on the op amp to about 4. (R2 =330) (R1=100)(3+1=4).


  1. As we talked, you need to make your mechanical portion much more complicated. Technical drawing is missing.

  2. Moaad, I like your mechanical part idea. I hope you can implement it. Your circuit is a bit simple. I want it to be more complicated. You also need a technical drawing. Check others.

  3. For Daniels set up, I also was having some difficulty with getting the 7 segment display resistors touching each other, to fix this I separated them into different rows and fed wires to the display instead, it took out the problem of them touching for me even when they get moved around a bit.

  4. For Moaads circuit, I really like your idea for the car being shot through a racetrack. I had a similar problem with the counter, and it ended up being a really easy fix, just messed up the polarity of the capacitors so you might want to look those over.

  5. To Mooad, I like your RG setup, its very creative. The thing i liked most about it is that you used the force sensor's resistance as a load for your op-amp. Some of the descriptions for your setup get unclear around the AND gate, and balloon portions when you explained the setup in #2. I'm not sure if Kaya wanted a circuit schematic or a block diagram. But i'm sure either one is fine as long as its clear. For your videos feel free to ask anyone questions in the future, or to look over your circuit's layout; I'm sure they'd be more than happy to help.

  6. Moaad, I like that the race car idea is versatile in terms of how it can trigger the next step in the rube goldberg machine. I identify with the struggle of having the resistors touch when they shouldn't; in the worst cases i put a small piece of paper between them.

  7. Daniel, your circuit definitely seems sufficiently complicated for this project; it's impressive that you have so many components. I also had a bit of difficulty with one of my relays. For me the issue was that I needed a very large gain and didn't want to overdo it.

  8. Daniel I think that your approach of many mechanical triggers is exactly what Dr. Kaya is looking for as it is more aesthetiacally pleasing. I hope that the increased number of mechanical triggers dosn't affect the machines reliability.

  9. For Daniel circuit, I really like how complicated your circuit is. It is hard to find what is the problem if you are using a lot of component and that will consume a lot of time. Also, your mechanical project, it is sufficiently complicated and I think that worth spending time. For you OpAmp failure, I was trying to use an OpAmp but it didn't work and i didn't so I used transistor which did the job. Great RG set up.

  10. Moaad, I like your circuit and I like how you used your FS to to turn on the OpAmp. Videos are missing in your blog but I see how you planning to do your RG.I hope it works. To get enough current to the motor, I used a transistor and that worked. For the resistors, you could separate them before you finish your set up, It took me a lot of to figure out what was wrong with my 7-segment.

  11. Daniel, I really like the design of your circuit, it really implements a lot of good ideas into it. What resistors did you use to amplify your op amps? Seems like you have a good amount of power leap when you apply them. Your circuit will allow a lot of time and that is really good.

  12. For Moaad, It's really cool that you have a motor that will push a car at the end that has a balloon attached to it. That's kind of like mine! Your circuit looks complicated and creative!

  13. For Daniel, I like that you put a lot of time into making your circuit work. It's really cool that you use a ball to knock down the domino's instead of just the motor doing the work. I think your circuit is complicated too!