Wednesday, April 26, 2017

Week 13: Justin Schafer

Week 13: Rube Goldberg Finalization

Problem 1:
Rube Goldberg Circuit Schematic

Problem 2: A Trebuchet launches a ball into a cup, which covers a photoresistor. This in turn increases the output of a transistor, which has it's output amplified by an non-inverted op-amp. If the photoresistor is covered, then a relay is switched, turning on a clock (555 Timer.) This clock's pulses are measured and counted by the 74193 Binary Decimal Counter. This chip then outputs the count into 4 bits of binary. The binary bits are connected each to a 7 segment display. When all the displays are lit up (all binary bits are at 1,) then the clock's pulses are blocked from the Decimal Counter via a relay that shorts the wire between the two. This produces a constant signal for the next Rube Goldberg part.

Problem 3: 
Trebuchet with sling removed to reduce speed of projectile.

Circuit implemented on bread board.

Giant Target Funnel


Problem 4: 


Problem 5: 
Some failures were due to inaccuracy of the trebuchet, this was solved with making a large enough target that missing is improbable. Another issue was inconsistent results when trying to use logic gates such as NOR to make flip-flop designs. This was solved by simplifying the design and using NAND gates instead.

Monday, April 17, 2017

Week 13: Dru Pikula

Number 1: Updated Computer Drawing


Number 2: Setup Explanation

From  past blog post, Week 12: Dru Pikula;
There is 2 photocell resistors that will allow the motor to spin when they are uncovered, the circuit will activate when photocell 1 becomes uncovered from being initially covered, which because of the voltage divider active the transistor and then the relay switch to allow the motor to turn on. The motor will active the physical/mechanical part of the Rube Goldberg not yet drawn, the motor will spin in a string on a rod object that will pull it off another, on the other rod another string will pull a block over the second photocell to turn off the motor after the motor activates the next persons circuit.

Only thing I changed is adding in the 555 timer and LEDs so that half of the leds will be on when the other half is off using the nand gate as a not gate on the 555's output clock signal. The Leds will be used as a pure visual element for the Rube Goldberg.

Number 3: Photos



Number 4: Videos 


Number 5: What Failures I had
A problem that did happen is the motor not sporting a a couple of times and pulling the string off of the pencils.

Number 6: Group RG setup
My RG Setup will be triggered by the previous with a bottle slowing falling off the table and pulling a  string which will uncover my first photo resistor.  My will trigger my group mates by pulling a string and a pin on his catapult to start his RG setup.

Number 7: Video of group test run
Partner didn't show up couldn't record video.

Monday, April 10, 2017

Week 12 Justin Schafer


Rube Goldberg Trebuchet:



For the Class Rube Goldberg project I decided to use a catapult. After researching different types, I settled on the trebuchet due to the physics that would be interesting to recreate on a small scale. I found the optimal ratios for the different components as well as a sturdy, simple design.

Autodesk Inventor Schematic:

For the electronic side of my design, I have two bread boards, one that is covered and one that is not.
The first one is covered by the target, in order to keep it dark. However, a small amount of light is allowed in through the funnel. When this hole is covered, the Photoresistor will increase in resistance, which will then activate a relay after being converted into the correct voltage via a Transistor and Operational Amplifier. The relay is then connected to a 555 Timer, which has its pulses counted by a Binary Decimal Counter. The output from the counter is transferred to the other bread board.
The second bread board converts the outputs of the Binary Decimal Counter to 5 7 segment displays that spell out "gOAL!" (Has to be lowercase g due to limitations of 7 segment display.)
Bread Board Circuits:
In order to ensure that the projectile of the trebuchet does not miss, the proverbial "side of the barn" approach was used. A box was made to completely cover the first bread board, and on top of it, a large wall was made. This large wall was then connected to a hole in the top of the box via cloth. This created a soft landing for the projectile, mitigating most of the momentum of the projectile and preventing it from bouncing out. When the ball is sunk into the whole, the photoresistor activates the circuit.
Target:


Sunday, April 9, 2017

Week 12: Dru Pikula

Number 1: Computer Drawing





Number 2: Explanation of setup
There is 2 photocell resistors that will allow the motor to spin when they are uncovered, the circuit will activate when photocell 1 becomes uncovered from being initially covered, which because of the voltage divider active the transistor and then the relay switch to allow the motor to turn on. The motor will active the physical/mechanical part of the Rube Goldberg not yet drawn, the motor will spin in a string on a rod object that will pull it off another, on the other rod another string will pull a block over the second photocell to turn off the motor after the motor activates the next persons circuit.



Number 3: Photos
Whole Circuit

Voltage divider and Photocells

Relay and Transistor
Slide to slide over photo resistor

Motor and string

Number 4: Videos
Video of circuit working
Video of circuit with mechanical parts


Number 5: Failures
The main failures I've have so far have been getting the transistor to activate the relay, that was solved by bumping up the voltage to a value that would work just by slowing increasing it until it triggered.

Sunday, April 2, 2017

Week 11:

Part A: Strain Gauges:
Circular Gauge:


Flipping strength Minmun Voltage (volts) Maximum Voltage (volts)
Low -2.5 4.8
High -3.4 10


Square Gauge:

Flipping strength Minmun Voltage (volts) Maximum Voltage (volts)
Low -10.2 7.5
High 8.32 12



Part B: Half-Wave Rectifiers
Number 1:

Number 2:

Effective (rms) Calculated (volts) Measured (volts)
Input 7.64 7.52
Output 3.44 5.39

Number 3:
To get calculated RMS value of the input we multiplied the peak by .707 voltage. And to get calculated RMS  output we decided the peak by pi. The calculated and measured for the input line up well enough but not for the output we assume it's because the rectifier didn't fully remove the negative voltage signal.

Number 4:
Output voltages from above circuit:

Oscilloscope (volts) DMM (volts)
Output Voltage (P-P) 5 3.7
Output Voltage (Mean) 6.5 6.28
Number 5:

Same output voltages from Num. 4 but with a 100 nanoF capacitor.


Oscilloscope (volts) DMM (volts)
Output Voltage (P-P) 0.24 0.0567
Output Voltage (Mean) 7.17 7.16

Part C: Energy Harvesters
Number 1:
Tapping Table:

Tap Freq Duration (seconds) Outout (rms mV)
1 Flip/Sec 10 242
1 Flip/Sec 20 413
1 Flip/Sec 30 513
4 Flip/Sec 10 280
4 Flip/Sec 20 742
4 Flip/Sec 30 773
Flipping Table:
Tap Freq Duration
(seconds)
Outout (rms mV)
1 Flip/Sec 10 230
1 Flip/Sec 20 290
1 Flip/Sec 30 640
4 Flip/Sec 10 840
4 Flip/Sec 20 1430
4 Flip/Sec 30 1600

Number 2:
The longer that you tap it and/or the faster you tap it the more the circuit seems to store generate more voltage and hold that voltage for longer.

Number 3:
If we don't use the diode in the circuit then the strain gauge won't charge the capacitor  at all.

Number 4: