This course provides students with an understanding and experience in semiconductor-based electronic devices. Students will troubleshoot and analyze passive and active circuits that focus on product implementation.
Please submit your documentation link here: Form
This class served as a quick introduction to Diodes and their basic functions. We built a test circuit using a standard 1N4001 rectifier diode and placed it in series with a small resistor. By utilizing a sinusoidal voltage from the function generator, we were able to look at the signal effects of the diode in this simple circuit. This class served as an exploration with function generators and basic use of the oscilloscope. Next class we will look further into the uses of the oscilloscope and more applications of diodes.
Diode Intro - Schematic
Diode Intro - Fritzing
How Does a Diode Work? - LearnEngineering
This class took diodes to another level. Looking at half wave and full wave rectification using standard 1N4001 rectifier diodes, we built the basis for a power supply. Next class we will build a full 5V power supply for future projects and utillize linear regulators, like the LM7805 . Below are some of the basic calculations for our bridge rectifiers:
We are spending the class period building 5V power supplies that we can use throughout the remainder of the semester. We will use the base schematic to begin and also build a safe enclosure for our power supplies.
Power Supply - Schematic
Power Supply - Fritzing
Please submit your documentation link here (if you have not done so): Form
Inside Transformers - JB Calvert
We are finishing the final pieces to the power supply. The power supply along with your documentation needs to include the following:
Completed circuit, soldered to protoboard or pcb
Safe Enclosure with terminals (MakerCase)
Fuse protection, Power-On indication, Switch
Oscilloscope - Transformer, Full Bridge, and Linear Regulator
Original schematic of finalized design
This class introduced bipolar-junction transistors (BJT) and characteristics of BJTs. We looked at the 3904 NPN transistor as a model for a common, general purpose transistor.
This class was devoted to finishing the soldering and enclosure on the power supply. We reviewed the NPN transistor circuits and looked at a few examples. We built a small switching circuit that tested our equations against the error and leak of the 3904 NPN transistor.
We reviewed our properties of the NPN Transistor and looked at the basics of saturation and cutoff voltages by driving various currents through a basic circuit. The main objective of this class was to develop a circuit that:
Find the saturatation and cutoff points utilizing a 3904 NPN transistor and a variable load
Look at forward and reverse bias using the diode funtion on your DMM
Create a switching circuit - What are the saturation and cutoff points/What is the active region of the transistor? Test all of the voltages and use our calculations to compare real values with ideal values
Create a safety component to your circuit that will detect reverse bias
Draw a schematic of your circuit and indicate voltages at various components as well as the current in both legs of your circuit
Here is a document with the examples we used in class:
Transistor Equations v1
This class was spent making sure we can recreate and compare actual values of our transistor switching circuit to the values in the datasheet or those collected. Refer to last class information for more details on what you should be documenting or have present for next class. We will compare values and troubleshooting strategies next class.
We looked further into calculating values for saturation and cutoff for our NPN transistor. The datasheet will help provide a sense of where to look when selecting values to saturate your base ont he transistor. Play around with these values and see if you can find these points.
Saturation/Cutoff Equations v1
We introduced signal amplification in this class. We built a basic circuit using the function generator as our signal input and stuck to the 3904 NPN transistor to modify the signal. This class was meant to be an experimental class looking at the functions of the waves on the oscilloscope by playing with the frequencies on the function generator.
Amplifier Equations v1
During this class we focused on building a simple signal amplifier. We worked on a small mono speaker schematic and some 8 ohm speakers while looking at our waveform on the oscilloscope. We are going to take this project to a higher level and introduce modifications and protection.
Basic Amplifier Schematic
Look up LM380/LM380N datasheet
Adjust capacitor values from original schematic
Change potentiometer type
View outputs on oscilloscope
Further research on LM380 amplifiers
Design schematic/pcb/protoboard for amplifier
Build a small compact speaker with built-in amplifier
Other modifications... stereo, switches, battery, indicator lights, sound-level meter, etc.
You must optimize this circuit design!
Justify your design decisions
We are working on finalizing and finishing our amplifier designs in class. The circuit should be soldered to protoboard and fully tested. The tests should include a range of frequencies and a nice clean view of the frequency on the oscilloscope for documentation. Please make sure to adjust your schematic for your particular modification. You should also build an enclosure next class for your product. I would encouragea laser cut simple box with an interface to your product. Refer to the last post for more information on what to include in the project. Schematics are listed above as well.
This was the last class to work on your amplifier design project. We will share our additions and projects during the next class. Most of you are close to finishing soldering and putting your project in an enclosure. Next class we are going to start Bias Circuits with Transistors and begin our last project of the semester.
We spent the class sharing our amplifier designs and comparing the projects with each other using "Sweet Caroline" as our testing song. There was a short introduction on DC operating points and voltage dividers with BJTs. Your last lab project will be slightly open-ended applying transistor knowledge to an application. Your goal is to modify a control signal and use a transistor as a switch to operate an external application. More details to follow.
DC Operating Point - Notes
We worked on comparing amplifiers and types. The below link is a great overview of transistors. We spent the class period developing schematic for our projects that includes a switching circuit and signal amplification.
Amplifiers - Sparkfun
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 with Oscilloscope, show input and output signals
Your Presentation will include:
Demo of the working prototype
Issues along the way?
Don't forget to include all of the above in the submitted documentation. The documentation will be due at the end of class. Presentations will start at exactly 5:45 PM. Presentations will be 5 minutes in length. See you then.