Week 13 Group Blog

Week 13 Group Blog

6. Group task: Explain your group RG setup.
Our group's circuit will start with Nick's circuit. Nick from the previous group will lift a weight of of a button to start our circuit. Once our Nick's circuit is started, a 555 timer will start pulsing. This 555 timer is hooked up to an op amp, photocell, and a transistor. These components will make a motor spin, and then with light from a phone shining directly on the photocell, make the motor spin even faster. (See Nick's individual blog 13 post). Once this motor is spinning faster, it will be able to lift a weight off of the button that starts Mary's circuit using a pulley.

After Nick sets off my circuit I will have 3 displays showing the numbers 393. From there the displays will lead to an XOR gate. The gate will have a combination of 1 and 0 as inputs so the output will produce a 1 and that will connect to a relay. The relay will light an LED which will help to generate power to a motor. The motor will releases golf ball from behind a gate and the golf ball will travel down a ramp and hit Alec's switch which will start his circuit up.

Mary's circuit will inevitably release a golf ball to flow down a ramp which will collide into my switch and activate the circuit. It is unclear right now what is happening electrically with the circuit. However, that is a summed up version of the mechanical process.

7. Group task: Video of a test run of your group RG.
There is no group video because the other circuits are incomplete. We have a group of and only 2 power supplies so it is difficult to work on the projects at the same time. For that reason, that project is theoretically working. However, we have no footage, or attempts at the circuit. This is, as stated before, because of the lack of resources.

Mary Stepho's Blog for Week 13

1)

My circuit will start by a switch which isn't shown when that switch is triggered by the person before me my circuit will turn on 3 displays. The displays will have the numbers 393 written on them. That will go to an XOR gate. The input of the XOR gate will be 1 and 0 so the output will become a 1 and that output will travel to a relay. From the relay the output of it will send current to an LED. The LED will go to a photocell and that will power a motor to spin. Once the motor is spinning it will release a ping pong ball that is placed behind a gate and the ball will roll down a ramp I made and that will set off Alec's circuit. 

2)

Failed attempt

Success Attempt

3) I had one failure and that was my LED was placed correctly so that caused my motor which needs my LED to turn on fail. I re-looked at my circuit and figured it out. I also learned that I do need to add something extra to my circuit because it isn't the most complicated out of everyone else's.

Alec Omell Week 13

Video Explanation about my Rude Goldberg system

Picture of the main electrical components of the circuit

Picture of the cart the cart that will activate the display

Picture of the winding mechanism

Picture of the motor, switch and strain gauge. The strain gauge will be displayed on the oscilloscope 

Video of successful attempt

Video of a failed attempt

Challenges:

One of the more challenging aspects of the Rube Goldberg system was the mechanical portion of the project. The building of the circuit was the easy part, for me. However, trying to figure out what pieces to use on the motor, the type of string, the diameter of wheels, etc. A lot of trial and error was used to figure out what I should use. I did you prior knowledge to infer on certain parts. I wasn't going to pick a really large wheel for example because their would be more friction. 

The string that cranks the wagons in gave me a huge headache. It continuously got tangled and I tried using different string, different motors, different tensions. Finally I came to the conclusion of the correct string, with the correct motor speed and motor piece that winds the string.

Group Task:

Mary's circuit will inevitably release a golf ball to flow down a ramp which will collide into my switch and activate the circuit. It is unclear right now what is happening electrically with the circuit. However, that is a summed up version of the mechanical process.

There is no group video because the other circuits are incomplete. We have a group of and only 2 power supplies so it is difficult to work on the projects at the same time. For that reason, that project is theoretically working. However, we have no footage, or attempts at the circuit. This is, as stated before, because of the lack of resources.

Nick Polega Week 13

Nick Polega Week 13

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

2. Explain your setup.
My setup begins with a weight being lifted off of a button, which will start my circuit. Once the circuit is receiving power, a 555 timer will begin pulsing. I made its pulses very very short because I want the motor to spin the arm like an analog clock would. The pulse signals from the 555 get amplified by the non-inverting op amp to about 9 V. This signal goes to the emitter of a transistor. This all causes the motor/analog clock to take about 6 or 7 pulses (or ticks) per 1 revolution. Also attached the the transistor is a photocell at its base with a flashlight mounted above it. While the photoresistor is covered the motor spins fast enough to knock over dominoes but not fast enough to lift the weight. Once the dominoes are knocked off the edge of the table, The base of the transistor has a higher current, therefore so does the emitter. This causes the clock/motor to spin much faster and smoothly. This will lift a weight off of a button which will start Mary's circuit.
3. Provide photos of the circuit and setup.

4. Provide at least 2 new videos of your setup in action, one being a failed attempt.

This was my one of my many failed attempts. The string got caught in the gears that turn the motor, causing it to bind up.



This was my most successful attempt. As you can see, The motor doesn't really have enough power to lift the weight. I am working on a solution for this now.

5. What failures did you have? How did you overcome them?
One of the failures I am currently working to overcome is that my motor will not lift the weight up as high as I want it to. It lifts it a little bit, but I would like my circuit to work nearly 100% of the time before the class demo. I will try to overcome this by using less string and maybe greasing up the pulley. This leads me to my next obstacle, which is getting the circuit (especially the mechanical parts) to be sturdy and work 100% of the time. I am overcoming this my redesigning aspects I feel are weak and also doing a bunch of test runs. The final obstacle will be getting my group's/the class' circuit to all run smoothly. The whole class is in the process of this currently but it seems as if collaboration is key. Something else worth mentioning, this is my 4th circuit I've designed. I had trouble the last couple weeks coming up with a direction that would be sufficient to the rubric and also work well. After class on Friday, Alec stayed a couple hours afterwards to help me figure something out. I am happy my design now.

Mary Stepho's Blog Week 12

1) This is the computerized version of my Circuit Schematic

2) Here are more in depth pictures and both of my attempts with 1 failed attempt.

This is my circuit from the left.

This is my circuit from the front.

This is my circuit from the right.

Here is a video showing my first attempt which failed. The switch, displays, op-amp, relay, and LED, and photocell, and transistor work fine. I came to realize that my motor wasn't connected correctly. I placed one of its end in the power supply when it was supposed to go to ground.

Failed attempt as explained above.

This is my second attempt which was a success, because I fixed my earlier problem of the error in motor connection to my breadboard.

Successful attempt as explained above.

3) There were 2 tricky things I had to figure out in this lab. One was how was I going to be flashy at the end, because I am the last person, and how was I going to make everything work.

I addressed the first problem with Kaya. I decided instead of knocking down domino's to spell out 393 I would instead make a rig that will let out a helium balloon. I am still in the process of designing that rig, but my circuit works perfectly.

The second problem was how was I going to make all of these components work with one another. I decided to list all of the components I wanted to use, and then went back to previous weeks as referencing to what I was using. This helped a lot because it reminded me of how these components like the photocell or relay, etc..., are set up. So then I mimicked those blogs and made it fit my personal circuit and that solved my second problem.

Alec Omell's Blog Week 12

A computer drawing of the circuit diagram

Fig1: Switch that activates the whole system

Fig 2: The OP amp, transistor and photo cell that supply current and voltage to the motor

Fig 3: The motor that winds the string and pulls the carts towards them

Fig 4: the cart collides with ramp and the ball rolls down

Fig 5: DMM measures the voltage being output by the straingauge

Fig 6: the strain gauge is measuring the force of the motor

Fig 7: A setup of the function motor piece that properly winds the carts

FIg 8: the secondary cart that will be used to activate a phone

Fig 9: The primary cart that will be used to transport the ball

First Attempt at the Rude Golderberg system

Second Attempt at the Rude Golderberg system

Third Attempt at the Rude Golderberg system

Video Explanation about my Rude Goldberg system

One of the more challenging aspects of the Rube Goldberg system was the mechanical portion of the project. The building of the circuit was the easy part, for me. However, trying to figure out what pieces to use on the motor, the type of string, the diameter of wheels, etc. A lot of trial and error was used to figure out what I should use. I did you prior knowledge to infer on certain parts. I wasn't going to pick a really large wheel for example because their would be more friction. 

The string that cranks the wagons in gave me a huge headache. It continuously got tangled and I tried using different string, different motors, different tensions. Finally I came to the conclusion of the correct string, with the correct motor speed and motor piece that winds the string.

Nick Polega Week 12

Nick Polega RB Idea

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

2. Explain your setup.
My plan starts with the ball from Alec's circuit knocking down dominoes. The dominoes will split into two paths, with staggered timing (to demonstrate the AND gate). One path will end with a domino falling on the FORCE RESISTOR and the other will end with a domino attached to a cloth covering the PHOTO-RESISTOR. When this happens, these two components will have a small enough resistance at this point to have voltage flow to the AND GATE. This gate will do two things once it has an output: allowing a message to display across the six 7-SEGMENT DISPLAYS and acting as the positive input on the NON-INVERTING AMPLIFIER. This will amplify the voltage enough to switch the RELAY. The now switched relay will power a MOTOR to spin and lift a weight using a pulley. The lifting of this weight will trigger the next RB.
Edit 4/11/17: I was unable to figure out the AND gate and the photoresistor correctly before the deadline. I am still interested in incorporating these elements into my circuit perhaps with my group's help. Also, two more non inverting amps were needed to get the displays as bright as I wanted them.
3. Provide photos of the circuit and setup.
4. Provide at least 2 videos of your setup in action (parts or whole), at least one being a failed attempt.
5. What failures did you have? How did you overcome them?
My biggest problem was coming up with a decent circuit design. At first, I was trying to use a solar panel to begin my circuit. These kept breaking on me repeatedly so I lost a lot of time trying to fix/find a new one. After taking a deep breath, I eventually just decided to scrap my previous design altogether. This led to a lot of time lost but I overcame it by talking/taking suggestions from classmates and managing my time more efficiently after class Monday.

Week 11

Part A: Strain Gauges:
Strain gauges are used to measure the strain or stress levels on the materials. Alternatively, pressure on the strain gauge causes a generated voltage and it can be used as an energy harvester. You will be given either the flapping or tapping type gauge. When you test the circle buzzer type gauge, you will lay it flat on the table and tap on it. If it is the long rectangle one, you will flap the piece to generate voltage.

1. Connect the oscilloscope probes to the strain gauge. Record the peak voltage values (positive and negative) by flipping/tapping the gauge with low and high pressure. Make sure to set the oscilloscope horizontal and vertical scales appropriately so you can read the values. DO NOT USE the measure tool of the oscilloscope. Adjust your oscilloscope so you can read the values from the screen. Fill out Table 1 and provide photos of the oscilloscope.

Table 1: Strain gauge characteristics

Flipping Strength	Minimum Voltage	Maximum Voltage
Low	.6 V pk-pk	1.4 V pk-pk
High	1.32 V pk-pk	3.54V Pk-pk

Table 2: Buzzer gauge characteristics

TappingStrength	Minimum Voltage	Maximum Voltage
Low	2.4 V	2.8 V
High	5 V	6.2 V

Flipping test with high strength Max value 

Flipping test with low strength Max Value

Flipping test with high strength lowest value

Flipping test low strength low value

Tapping test low strength, low value

Tapping test low strength, high value

Tapping test high strength, low value

Tapping test high strength, high value

Part B: Half-Wave Rectifiers

1. Construct the following half-wave rectifier. Measure the input and the output using the oscilloscope and provide a snapshot of the outputs.

Schematic of the Half Wave rectifer

2. Calculate the effective voltage of the input and output and compare the values with the measured ones by completing the following table.

Table 3: Showing the RMS values calculated and measured

RMS Values	Calculated	Measured
Input	3.53 V	3.6 V
Output	3.53 V	2.07 V

3. Explain how you calculated the rms values. Do calculated and measured values match?

To measure the RMS value you take the appropriate voltage, in this case 10 V. Then you divide it by square root 2.

4. Construct the following circuit and record the output voltage using both DMM and the oscilloscope.

Table 4: Showing the varying output voltages obtained through different measuring mediums with 1uF

	Oscilloscope	DMM
Output Voltage (p-p)	5.4 V	1.47 V
Output Voltage (mean)	5.5 V	5.77 V

5. Replace the 1 µF capacitor with 100 µF and repeat the previous step. What has changed?

Table 5: Showing the varying output voltages obtained through different measuring mediums with 100uF

	Oscilloscope	DMM
Output Voltage (p-p)	.16 V	.02 V
Output Voltage (mean)	6.83 V	6.75 V

Part C: Energy Harvesters

1. Construct the half-wave rectifier circuit without the resistor but with the 1 µF capacitor. Instead of the function generator, use the strain gauge. Discharge the capacitor every time you start a new measurement. Flip/tap your strain gauge and observe the output voltage. Fill out the table below:

Table 6:

Tap Frequency	Duration	Output Voltages
1 flip/second	10 Seconds	.26 V
1 flip/second	20 Seconds	.43 V
1 flip/second	30 Seconds	.4 V
4 flips/second	10 Seconds	.44 V
4 flips/second	20 Seconds	.506 V
4 flips/second	30 Seconds	.514 V

2. Briefly explain your results.

The longer we flipped the stress the gauge the more the capacitor was being charged. Therefore, the DMM was reading higher values. The same is also true for when we flipped it 4 times a second. The flips generate a voltage, and the capacitor stores the voltage, while simultaneously draining. The more frequent the flips for a longer duration will produce an overall higher voltage.

3. If we do not use the diode in the circuit (i.e. using only strain gauge to charge the capacitor), what would you observe at the output? Why?

The output would be smaller because there isn’t a big rush of electricity flowing through the circuit. The diode we used in the circuit was meant to mimic a half-wave rectifier. We see that when we view our sin waves because there is no negative part this is because of the diode. When the diode is taken out there will have negative values since there is no half-wave rectifier being applied to the circuit.

4. Write a MATLAB code to plot the date in table of Part C1.

*Code we used to get the Half-Wave Rectifier Graph*

x=[10 10 20 20 30 30];
y=[.26 .44 .43 .506 .4 .514];
plot(x,y)
xlabel('Time (seconds)');
ylabel('Vout (V)');

grid on

Half-Wave Rectifier Graph

The graph of the half-wave rectifier using MATLAB.

*Code we used to get the Half-Wave Rectifier Graph*

x=[10,20,30];

Va=[0.26,.43,.62];

Vb=[.44,.506,.514];

plot(x,Va,'--k')

hold on

plot(x,Vb)

legend('1 flip/second','4 flip/second')

xlabel('Time (s)')

ylabel('Output Voltage (V)')

title('Half-Wave Recitifier')

Half-Wave Rectifier Graph

This is the graph of both of the Output Voltages, but they are separated.

Blog Week 10

Blog Week 10

1. Open MATLAB. Open the editor and copy paste the following code. Name your code as FirstCode.m

Graph created by the code given in the blogsheet

2. What does clear all do?
~~~~ Clears all predefined variables

3. What does close all do?
~~~~Closes all open windows such as graphs.

4. In the command line, type x and press enter. This is a matrix. How many rows and columns are there in the matrix?
~~~~ 1 row and zero columns

5. Why is there a semicolon at the end of the line of x and y?
~~~~ the semicolon prevents the data from being displayed after "ENTER" is hit.

6. Remove the dot on the y = 2.^x; line and execute the code again. What does the error message mean?
~~~~The dot is needed so that the operation can be applied to each of the values in the matrix

7. How does the LineWidth affect the plot? Explain.
~~~~ It affects the width of line. Smaller integers result in a more narrow line segment.

8. Type help plot on the command line and study the options for plot command. Provide how you would change the line for plot command to obtain the following figure (Hint: Like ‘LineWidth’, there is another property called ‘MarkerSize’)
~~~~plot(x,y,'LineWidth',6,'LineSpec',-or)

9. What happens if you change the line for x to x = [1; 2; 3; 4; 5]; ? Explain.
~~~~ It turns into a single column matrix starting at 1 and ending at 5

10. Provide the code for the following figure. You need to figure out the function for y. Notice there are grids on the plot.

x = [1 2 3 4 5];

y = x.^2;

plot(x, y,':sk', 'LineWidth', 6,'Markersize',20)

xlabel('Numbers', 'FontSize', 12)

ylabel('Results', 'FontSize', 12)
grid on

GridLineStyle ':'

11. Degree vs. radian in MATLAB:
a. Calculate sinus of 30 degrees using a calculator or internet.
Sin(30)= 1/2
b. Type sin(30) in the command line of the MATLAB. Why is this number different? (Hint: MATLAB treats angles as radians).
By default MatLab uses radians

c. How can you modify sin(30) so we get the correct number?
~~Sind(30)

12. Plot y = 10 sin (100 t) using Matlab with two different resolutions on the same plot: 10 points per period and 1000 points per period. The plot needs to show only two periods. Commands you might need to use are linspace, plot, hold on, legend, xlabel, and ylabel. Provide your code and resulting figure. The output figure should look like the following:

t=linspace(0,.125664,10);
y=10*sin(100*t);
plot(t,y,'-or')
hold on
clear t
t=linspace(0,.125664,1000);
y=10*sin(100*t);
plot(t,y,'k')
xlabel('Time (s)')
ylabel('y function')
legend('Coarse','Fine')

13. Explain what is changed in the following plot comparing to the previous one.
~~ The FINE graph has a limit set so that its max value is capped at 5

14. The command find was used to create this code. Study the use of find (help find) and try to replicate the plot above. Provide your code.

t=linspace(0,.125664,10);
y=10*sin(100*t);
plot(t,y,'-or')
hold on
clear t
t=linspace(0,.125664,1000);
y=10*sin(100*t);
k=find(y>5);
y(k)=5;
plot(t,y,'k')
xlabel('Time (s)')
ylabel('y function')

PART B: Filters and MATLAB

1. Build a low pass filter using a resistor and capacitor in which the cut off frequency is 1 kHz. Observe the output signal using the oscilloscope. Collect several data points particularly around the cut off frequency. Provide your data in a table.

~~We need a 7.5k resistor to achieve a cutoff frequency of approximately 1kHz

Table created from the frequency and the associated output in a low pass circuit

2. Plot your data using MATLAB. Make sure to use proper labels for the plot and make your plot line and fonts readable. Provide your code and the plot.

Graph created from the table above. The code used is provided below

****CODE*****

x=[.1 .2 .3 .4 .5 .6 .7 .8 .9 1 2 3];

y=[3.655 3.603 3.525 3.424 3.3 3.177 3.04 2.904 2.767 2.6 1.62 1.07];

plot(x,y)

xlabel('Freqency (KHz)');

ylabel('Vout (V)');

grid on

3. Calculate the cut off frequency using MATLAB. find command will be used. Provide your code.

R=7500; C=22*10^-9;
Cutoff=1/(2*pi*C*R)
----------------------> 964.5754 Hz

4. Put a horizontal dashed line on the previous plot that passes through the cutoff frequency.

Graph with dashed line across the cutoff point. This graph is identical to the graph above

5. Repeat 1-3 by modifying the circuit to a high pass filter.

a)Table for high pass filter

Table created by frequency and the associated output of a  high pass filter circuit

b)Graph for a high pass filter

Graph created from the table above. The code used is provided below

***CODE***
%%
x=[.1 .2 .3 .4 .5 .6 .7 .8 .9 1 1.5 2 2.5 3];
y=[.35 .687 1.007 1.303 1.572 1.811 2.02 2.203 2.361 2.495 2.912 3.063 3.082 3.034];
plot(x,y)
xlabel('Freqency (KHz)');
ylabel('Vout (V)');
grid on

c)Calculate Cutoff of high pass filter

R=7500; C=22*10^-9;
Cutoff=1/(2*pi*C*R)
----------------------> 964.5754 Hz

~~This cutoff is the same for both low pass and high pass filter.