Digital Electronics Final Project

This haunted house will use these devices to scare people more and give them more of a thrill when they go to the haunted house.

Control system 1 will be a a door closing behind someone as they walk into a room. It will close when a light sensor senses darkness when the person covers it, and a pressure sensor will be located underneath the tile that the person will stand on. The logic gates that will be used are the 'not' gate and the 'and' gate. We will use the 'not' gate because the light sensor usually senses light, but we want to to sense darkness. The 'and' gate is needed because we want it to work only when both sensors sense something. The door will only close when both conditions are filled.

Control system 2 will be a ghost popping out from a hiding place when someone walks into the room. It will pop out because we will have a microphone and a heat sensor that can hear someone's footsteps as they walk in. For this, we will used the 'or' gate because if one of them fails, we will have a back up to make sure that it works. The ghost will pop out if the microphone picks up the sound of footsteps, or the heat sensor senses one's body heat, or both.

Control system 3 will be the lights going out when a person walks into the room. The person will walk off of a pressure sensor, and another heat sensor will sense their body heat. For this device, we will use the 'not' gate and the 'and' gate. The 'not' gate is necessary here because the pressure is being released as a condition. The pressure sensor usually works when pressure is applied, not released, so we need the 'not' gate. The 'and' gate is needed because we want it to work only when both sensors sense something.

Electromotor

Electromotors work by electricity passing through the paper clips and into the sanded side of the armature. Then, an electromagnet is created. The north pole of the electromagnet and the south pole of the field magnet attract and the armature starts spinning. Then the non sanded side touches the paper clips, but since paint is an insulator, it shuts off the electromagnet. Momentum keeps it going, and as the sanded side touches the paper clips again, the electromagnet is turned back on. The poles of the magnet are reversed, and it keeps on going. Electromagnets are used in anything that rotates and is powered by a battery.

Design Proposal Blog Post

The vehicle is built to be able to travel both in land and in the air. We made it a scooter because that way more people will be able to use it as building it requires less money than a car or an airplane. The wings are taken from airplanes and the idea of rockets in the back  The thrust is from a controlled rocket engine. We did rockets because rockets have a large amount of thrust because of the hot gases pushing out and Newton's third law says that the opposite force will be big if the original thrust is big. But our rocket engine is controlled so that steering wouldn't be too difficult. My flight vehicle will have a large amount of lift because the area of the wings are large. This is true because of Newton's 3rd Law of motion. There is more area pushing down, so there is more pushing up as well. We have made the scooter as flat as we could so that we would minimize drag and the wings wide so that lift will be increased and the effects of the weight/gravity would be decreased.

Model Rocket

The thrust of my rocket was provided by the propellant in the engine and the hot gases that came out. The stability of the rocket affected the flight because of the fins. If the fins weren't stable, then the rocket would have more drag and would go as high as fast. Another factor that affected the flight of the rocket was the weight of the rocket. Looking at the results, since this rocket doesn't have much lift like an airplane does, the weight of the rocket affects the flight a lot. The lighter the rocket, the amount of time it took to get to the maximum was usually longer.

Glider Construction

We made gliders with foam, glue, and tape. We could add washers for weight, but it was pretty hard. We had limited time and materials. After constructing it, we were to fly it outside to for hangtime, accuracy, distance, and safe landing. We only had 10 trials for testing. Our glider had large wings for lift, so we didn't have too much drag. We added a washer for weight so it would be more stable. The airfoil had a large angle of attack, camber, and surface area. The tail controlled pitch, yaw, roll, and had an elevator. While constructing our airfoils, we kept Bernoulli's Principle and Newton's 3rd law of motion. After we defined the problem, we used our brains to think of good designs for airfoils that would generate lots of lift and little drag for the best glider. We narrowed down our glider some and added a washer for weight because it kept flipping over in mid air.

Results of Flight:
Hang Time Average: 1.34 seconds
Distance Average: 16.4 ft.
Safe Landing: 70%
Accuracy: 60%

My self evaluation is 12/12

Hot Air Balloon

Well, today we flew our hot air balloons that we built last class. Our balloons were made out of tissue paper and glue. We launched our balloon 3 times today. When we built them, we had about 50 minutes of time and we could only use tissue paper and glue. After we launched it once, we repaired the holes and launched it again. After that, we decided that we could make it stay in the air even longer so we added some paper clips to the bottom rim of the balloon to weigh it down a bit. Those were our revisions to make our balloon better.  Our balloon flew the highest then. After doing that, we could've made it better and better, making more revisions or maybe even a completely new balloon. Doing this would be an example of the design process being circular and our devices being ever changing in engineering.

 This is our first attempt at flying our balloon.

This is our second attempt, with the holes repaired a little.

This is our third and last official attempt with the paper clips in.

Design Process and Highrise Tower

Our project was to use the design process to make the tallest highrise tower that could withstand a fan in our class on high. The tower had to be at least 18 inches high and had to hold a tennis ball at the top. The height was measured to the tennis ball, and if the tennis ball or tower fell down, then your tower wasn't stable. The materials that we got to use for this project were paper, tape, popsicle sticks, and string. Our design wasn't the greatest, but it was really fun to make and we were at least hoping to get the prize for the most unique tower as our's was only 19 inches, which is barely tall enough to satisfy the criteria. Unfortunately, we didn't get the most unique, but at least our's didn't fall down.