Software used in the previous semester included Fritzing and Inkscape. Here are two refresher videos to help you get back into using the software:
Intro to Fritzing: Schematics
Fritzing & Inkscape: PCB Isolation
Please submit your documentation link here: Form
We reviewed basic resistor series-parallel circuits from the previous class. We finalized our review of series-parallel and voltage divider applications by building a Wheatstone Bridge. Everyone was given a random resistor and compared values utilizing a multimeter and potentiometer. These basic labs will help us learn troubleshooting and circuit analysis techniques.
Wheatstone Bridge - Schematic
Wheatstone Bridge - Fritzing
Today we discussed circuit analysis basics and some circuit design. We did some troubleshooting and developed an understanding of Thevenin and Norton Equivalent Circuits.
We will begin troubleshooting using a circuit that uses a light dependent resistor/photocell and 10K resisitive soft potentiometer to determine the optimal instensity of a 10mm super bright LED comparing it with the environment and user interaction.
This class is focused on finishing our light products, developing a circuit, schematic, physical model, and pcb/perfboard layout.
Below are the basic needs to build the mini lamp project with two 10mm LED Lights:
Bill of Materials:
10-24 x 1.5" Pan Head Bolts, Nuts (x8)
Photoresistor, Trimmer Potentiometer, SPST Switch, 9V Battery/Holder, 10mm Bright LED (x2), Resistors
Please submit your documentation link here (if you have not done so): Form
We are going to look back on superposition and source changes before looking into Thorton and Thevenin Equivalent cicuits in network analysis. Superposition states that voltages and currents in a multisource circuit by calculating each of the individual circuits per source and combine the results.
Please check out these examples:
Superposition Examples - Problems
The lamp project should be finalized by the end of next class. Make sure to look for some lab time to complete this. Add all of your research and testing into your documentation so that it is clear and concise.
We focused on finishing our lamp project. Everyone should have begun soldering their components together and had working prototypes on the breadboard. Remember to make sure that your adjustment potentiometer has a decent range in comparison to the LDR. The remainder of the class was spent reviewing Superposition, Supply Change and Thevenin's Theory.
We have completed our analysis of DC Circuits using Superposition, Supply Changes, Thevenin Voltage Theory, and Norton Current Theory. Below is the example problems and equations we used in class for your reference:
Thevenin and Norton Theorem Examples/Problems
We are not going to have anymore time to work on the lamp project officially in class so make sure that you complete the project and include your final version in the documentation. We are going to look at magnetism and inductance in the coming 2 weeks. This will lead us into the AC portion of the class. Next class we will have the chance to look at magnetism and build components in an ideal fashion calculating the proper voltage, current, wire wraps, and conductive materials to complete a task. One topic suggested was building a portion of an automatic pinball shooter using solenoid. We may develop parts of a larger whole using solenoids to accomplish a task.
We will not be holding a physical class, but we will be beginning our introduction to magnetism. I will be hosting a chat from 4-5 PM tonight on Google Meet. The meeting code is oarfymxsie.
We will start in Chapter 8 of Paynter - please read as a background. We will move to Chapter 10 - Inductance at the start of the next class. We will focus on Faraday's Law of Induction. As a follow up please view this wonderful lecture listed below on Electricity and Magnetism by Walter Lewin. As our next project we will be designing an application for a solenoid. For the next week, think about what you want your solenoid to accomplish. We will be measuring these with galvanometers and our DMMs. Come to class prepared to begin testing out your theory. We will discover the relationship between windings of magnet wire, size of the solenoid, current draw, and voltage applied to the circuit to create a linear force.
For next class, please read the material above, watch the below videos for more context, and write up your ideas for how a solenoid will work and be prepared to justify it with an application. The previous post from last class has good animations on solenoids. I will expect everyone to share their ideas so that we can all properly calculate the requirements for optimizing a solenoid for our individual applications.
We began our journey into creating solenoids for an application. Your goal is to build a minimal and efficient solenoid that can be optimized for your application. The basic components include magnet wire, a non-conductive layer material, and a conductive core. For your application you should look into researching why your solenoid will work the way it does. You should build a prototype to find a baseline for your research and implement your solenoid after that. Be sure to include the number of wraps, what guage magnet wire, the length, and see if your actual solenoid matches a calculated force for the application. We will be finishing these next class and conclude the basis for magnetism before spring break.
We spent the class finishing our solenoid designs. We reviewed magnetism prinicples and how to control functional devices. We shared our designs with the class and developed additional needs and tests for our design. What worked? What went wrong? We spent the latter portion of the class finishing our designs of solenoids and building our documentation. This class serves as an introduction to the basic magnetism principles. Next class we are going to go into Alternating Current and Voltage.
Magnetism - Class Notes
Magnetic Forces - Khan Academy
We had a guest speaker, Gigi Davis, from Career Services share information and services on internships, jobs, help with resumes/interviews and resources at PVCC that can help you aqcuire jobs and internships. Her email is firstname.lastname@example.org.
The latter portion of the class we introduced alternating current. We spent a little time talking about basics of alternating current. I will post the notes below.
Spend the next week deciding on your final project that brings multiple concepts from this class and ETR113 into your design. You will create a basic schematic for your project and select the proper components for your operation. I will go over more details next class, but come prepared to defend your idea next Tuesday. If you have questions, please email or meet with me during office hours.
Today we spent class reviewing our Alternating Current Concepts and comparisons on calculating alternating voltages and current. We reviewed creating simple projects in Fritzing and how to begin a simple PCB. Below are the lab concepts covered in class:
View a sinusoidal wave on the oscilloscope using the function generator. Create a wave with a peak voltage of 2V and on the same oscilloscope a wave that is 90 degrees offset from that original wave.
View a square wave on the oscilloscope using the function generator. Create a wave that has a 50% duty cycle. Create another wave that has the following attributes: V=2v, tw=1ms, T=10ms...What is Vavg?
View a triangle wave on the oscilloscope with the function generator. Find a triangle wave that has a slope of -5 v/s.
Identify your problem. What are you trying to solve? What already exists? How can you build on existing circuits?
Link your project to what was learned in ETR113/114. How does this demonstrate some of the overarching themes in electronics that we discovered?
Begin your schematic and bill of materials. You should have a prototype schematics of materials that we can select out of the lab space and if we do not have it - let me order it ASAP.
Begin a prototype on breadboard or start your PCB design so we can test it. Your completed project should have some enclosure, a circuit board, and full documentation on how to build your product.
No class due to college cancelling classes! Work on your independent project!
We focused on creating a finalized schematic and introduced calculating values for capcitors. Please utilize lab hours to complete your work on your indepedent projects. You should have a finalized schematic, PCB design, and prototype. The ideal solution includes a finished circuit board. You will demonstrate your working circuit in class and also describe your project in full, technical detail during the final exam. If you need anything, please schedule time with me or come in to work on projects.
This marked the final class to work on projects. The criteria for completion are below.
This was the final class to work on your projects.
Your project should include:
Breadboard with working circuit
Bill of Materials
Purpose of circuit and components
Testing and areas for future growth
Your Presentation will include:
Demo of the working prototype
Tests performed on the finalized board
Issues along the way?
Don't forget to include all of the above in the submitted documentation, including datasheets and schematics. The documentation will be due at the end of class. Presentations will start at exactly 4:15 PM. Presentations will be 10 minutes in length. See you then.