Week 3: Circuits
Overview
Using breadboards, wires, and a battery, we created a device to warn the user if they have any covid symptoms. LED's and an alarm correspond with the number of symptoms (0=green, 1=yellow, 2=red, 3=alarm).
Design Process:
To start the week, we worked on a circuit to help with the college admission process. A student would have to take either the ACT or SAT, and also take either physical geology or psychology. We created a truth table and a schematic (seen in the "College Admission Device" section) to visualize our ideas and arranged the circuit. After this, we began on our main device. We brainstormed about how we could set up and, or, and not gates to correspond each light with the amount of symptoms. After trial and error, we created a design on Circuit Lab (seen in the "Circuit Lab" section). Once we had our design finished, we started on the circuit. We got our wires mixed up a few times, but ended up finishing the device. Each light worked properly, and all of them turned off when all three symptoms were detected. However, the alarm didn't ever sound. We tried testing the alarm by plugging it directly into the battery, but it still didn't work. We believe the alarm was short circuited during the process.
Biomedical engineering and electrical engineering:
Biomedical and electrical are both engineering fields that are crucial to the development of medicine and electronics. They design devices to help people, as well as making their daily lives easier. Some examples of things biomedical engineers create are artificial organs, medical equipment, and develop medical drugs. Some examples of things electrical engineers make are radars, navigation systems, and other communication systems.
More on Biomedical and electrical engineering from our research paper: Design Process of Commercial Circuits
Series Circuits
A series circuit is the most simple type of circuit that has a connection from the power source to one or more resistors like a bulb. The resistors in a series circuit are connected directly to one another like a chain with the power/electrons from the power source flowing through the circuit from first resistor to last. Series circuits can be useful for simple applications such as string lights or circuits with a switch. A downside to series circuits is that there is voltage drop which is a result of the power gradually being lost throughout the circuit. We can see this happen in the first image where the yellow bulb is brightest and the brightness drops after the yellow bulb to the red, then to the green.
Parallel Circuits
The second type of circuits is parallel. Each component in a parallel circuit draws power directly from the power source rather than the preceding component like in a series circuit. Each component has its own branch and the voltage runs through each branch. In parallel circuits, voltage drop is not as present and we can see that in the pictures as all three bulbs are lit pretty well and the same as each other.
Truth Table:
Schematic:
College Admission Device:
We created a truth diagram, schematic, and circuit to determine whether a student should be admitted into college. To meet the requirements, the student must either take the ACT or SAT, as well as take either physical geology or psychology.
Truth Table:
Red Light (2 Symptoms):
Alarm (3 Symptoms):
Covid Detection Device:
We created a truth diagram, CircuitLab design, and actual circuit to activate LED's and an alarm based on covid symptoms. The green LED will light up when there is no symptoms detected, the yellow LED with one symptom, the red LED with two symptoms, and the alarm with three symptoms. Sometimes the LED's wouldn't light up, and sometimes multiple would light up when they weren't supposed to. We believe this was due to some of the wires being fried.
Green Light (0 Symptoms):
Yellow Light (1 Symptom):
Circuit Lab:
To the right is our circuit lab design. There are three switches (each with a different symptom) that connect to and gates, or gates, and not gates. Based on the amount of symptoms, voltage will be sent to an LED, which will make in light up. We had some trouble with the voltages, but we were still getting the right binary values for each light.
My Movie 10.mp4