There are no quizzes, tests, or exams in our ACES program. Put another way, you are NEVER put into the position of having a dramatically limited amount of time to demonstrate the skills you have acquired. You can invest as much (or as little) time into your reports as you choose. In return for being granted complete control over the depth and quality of your submissions I can place a premium on detail, precision, and the pursuit of perfection. So, my advice to you if you want to become exceptional is to follow the written and oral instructions carefully and, beyond the required elements of each report, demonstrate tasteful and appropriate creativity and imagination to distinguish yourself from the mediocre. Good luck and, remember, the race is long but it's over quickly.
Reports. Required Elements
If you do not submit your report by the deadline specified, you receive a mark of 0. This is done as a favour to you to help you appreciate that the real world will dismiss you if you can not demonstrate responsibility and accountability. You are to archive ALL of your reports in the single Word document, ER.docx. The first page is your Title page, followed by a multi-page Table of Contents, after which your reports begin. EACH report will start at the top of the next new page and, unless otherwise specified, consist of the following sections, in the order listed,
The vast majority of us can tell the difference between quality and rubbish in an instant. As a young scholar you have to decide what your name will stand for. It should matter very little whether you enjoy a task or not; if you're going to attach your name to something it is a direct reflection of who you are.
Project 1.3. The Analog Oscillator (aka Astable Multivibrator)
The Square Wave, a highly orchestrated sequence of alternating high and low durations, is the backbone of modern, digital, communication. The purpose of this project is to introduce you to the transistor and to demonstrate how it can be combined with other familiar analog components to produce an oscillating signal with properties similar to the digital square wave.
- Clean the lens of your phone's camera, as you will be gathering media (photos and videos) throughout this project, from start to finish, in support of your DER project summary due Saturday November 16.
- This project will test your organizational abilities as much as your nascent electronics' knowledge and skills. Part of the task includes thinking deeply about what you're doing.
- After studying the schematic of the Analog Oscillator below left undertake your prototype (aka, blinker, Astable Multivibrator) on your breadboard. When you are confident the circuit has a chance of functioning, apply 9V power. Debug as necessary and document the results with your phone's camera.
You may wish to experiment with the rate at which the LEDs are flashing by adjusting the sizes of the resistors.
|Analog Oscillator Schematic
||PCB: Dry Fit
- Once you have obtained your media, you can request the additional parts that include a printed circuit board (PCB) and three terminal blocks. Disassemble your prototype and 'dry fit' the parts on your PCB (above right) in a manner similar to the image to the right (click to enlarge). This is an important step to appreciate the full scope of the task that lies ahead and to avoid the risk of soldering parts incorrectly that can be difficult, or near imposssible, to repair.
- With your soldering area fully equipped with easy access to the required tools and conscious of the soldering techniques and strategies discussed in class and in this soldering video, you may begin the soldering stage. Remember,
- Never solder with the power plugged in.
- Your soldering station should be kept no higher than 300°C.
- Keep the parts as tight to the surface of the PCB as possible. The reverse tweezers can help with this.
- The soldering tip should be clean and tinned.
- Any longer than 4s with the soldering tip on the leg of a component runs the risk of damaging the parts.
- Solder the smaller components first: resistors, then transistors, capacitors, slides witch then, finally the terminal blocks, ensuring they face outwards to permit LED lead access to the screw terminals.
- On multi-legged semiconductors, it is good practice to solder one leg, solder another part, then return to the original part. This practice minimizes the cumulative heat effect on parts.
- If you have invested care and thought into your efforts, plugging your 9V adapter into a temporary DC Power Jack should yield the desired outcome: a pair of blinking LEDS. If it doesn't function as expected, prepare yourself for the best part: debugging. Seriously, few activities are as satisfying as analyzing and repairing a faulty system. Use the large illuminated magnifying glass to check all your solder joints. Confirm your polarized parts are in the correct way. Use the DMM to to perform continuity, voltage, and integrity inspections. You WILL find the problem without the need to ask for my intervention.
- Once everything is as it should, present a working circuit to Mr. D. to get your Power Jack. Assemble it as you did for your Capacitor Visualizer.
- Finally, present both for your Analog Oscillator case and screws for final assembly.
- DER. Starting on a new page, add the Project name and complete sections under the subheading: Purpose, Reference, Theory, Procedure, Media, and Reflection. Text is developed in accordance with the recommendations for Technical Writing and reflective of your much-improved formatting abilities. Graphic manipulation is undertaken according to the specifications laid out in the Engineering Report General Guidelines.
- Attach your DER to an email to handin with the Subject: The Analog Oscillator (aka Astable Multivibrator) by the deadline.
Project 1.2. The Capacitor Visualizer
Along with resistors, capacitors belong to a family of components known as passives in that they do not introduce a new source of energy into a circuit. Capacitors serve a number of useful functions in both DC and AC circuits. In completing this project you will strengthen your understanding that the capacitor (in series with a resistor), plays in the timing aspects of analog DC circuitry.
This project takes time to undertake properly, so be patient, and start early.
The schematic, below left, is of a straightforward test circuit that, in my view, best illustrates of the functional behaviour of an electrolytic capacitor in a DC circuit. You are familiar with the concept of a voltage divider from your first project. Looking at the junction (node) between S1, R1 and R2, we introduce the notion of a current divider as the current splits into two branches due to their parallel configuration.
We have discussed the charging of an empty capacitor and the effect this has on the capacitor in terms of its resistance (in AC circuits this property is referred to as reactance). In a DC circuit, a single RC Time Constant, denoted τ, can be expressed simply as,
where τ is measured in seconds, R is measured in Ω, and C is measured in F. Also discussed in class (p. 33) is the expectation that after 5 RC time constants the capacitor is virtually fully charged (5τ~99%). One of the objectives of this project is to observe and confirm the expected results.
- To achieve the best results for each of the numerous trials, the capacitor should be fully drained. In the Procedure section of your report, explain how this is achieved in the circuit to the right.
- On a breadboard, prototype the circuit above left as neatly as you can using the first pair of resistor-capacitor values in the table below. Connect the longer lead of the bicolor LED to the capacitor and the shorter lead to ground. This ensures the orientation that agrees with the schematic. Note: Be sure to drain the capacitor and measure the voltage with your DMM to be sure. Explain this step in your Procedure and explain any related issues you have in achieving this.
- Once connected, hold the momentary button down (for as is required) before releasing it. Note the behaviour of the LEDs in particular, and try to explain what electrical behaviour at work, throughout. Do this a number of times until you feel you understand the principles.
- Now, more formally, using the timer on your phone, and through observation, record the approximate charging time for a fully discharged state until your eyes can no longer detect a visible state change in the red LED. A DMM can be used for more accurate results. Perform at least three trials with the first Resistor-Capacitor pair and record the average.
- For your DER, you are asked to duplicate the table that appears below. In the third column determine and enter the theoretical (expected) time to fill. In the fourth column, enter your observed result.
- Repeat Steps 3 and 4 for each of the remaining 2 RC pairs in the table. Again, perform a number of trials with each pair and record the average.
- For your DER summary of this Project, you MUST remember to obtain media of your prototype (both still images and video), before you dismantle it to solder together your completed device on the PCB provided. Be sure to watch the Instructional video, prior to soldering. Finally, demonstrate a WORKING version of your soldered PCB to me by Thursday October 31 to obtain a custom case for your device.
- In your DER, be sure to include the required sections listed above. You are to provide your own Fritzing schematic It is up to you to decide the supporting images and graphics that engage your readers and leave them with a solid understanding of the concepts. The table above is large enough to be center-aligned on your page.
- Attach your (corrected) DER to an email to handin under the Subject Line: The Capacitor Visualizer by the deadline.
Project 1.1. Voltage H-Bridge
One of the most important skills an Engineer must possess is the ability to communicate, both in spoken word and in written form, in a highly structured format. Developing this skill takes much practice and this is precisely why the Design Engineering Report plays such a crucial role in our program, your mark, and your future.
With the skills gained over the past few classes, you are ready to prepare your first Design Engineering Report (DER) submission. Furthermore, you are required to be familiar with the Guide for Technical Writing and, through practice and regular editing, your sentence structure will improve. Poor grammar and spelling skills detract from your presentation.
The Voltage H-Bridge circuit provides a vivid reflection of the fundamental voltage, current and resistance concepts we explored and analyzed over the first dozen classes. A schematic of the circuit appears to the right. The letter H is clearly visible in the depiction as the crossbar spans two voltage dividers (one variable and the other, fixed).
- Create the Word document, DER.docx that includes a Title page, Table of Contents and headers and footers as discussed and developed in class.
- Each Project writeup in your ACES career starts on a new page.
- For this project, start a new page, be sure the page numbering starts at page (Arabic) 1, and place Project 1. Voltage H-Bridge in Heading 1 Style at the top of the page. Subsections, styled as Heading 2, must include,
- Purpose one or two short, well-constructed sentences that underscore the precise concept(s) being highlighted in his project
- Reference include a hyperlink pointing to the URL of this project description and any other online resource(s) you explored with advantage
- Procedure discuss the concept of a voltage divider in general, how it is employed in this circuit, what purpose it serves, and how the entire circuit works. Finally, include a complete, 3" wide, background-shaded, Parts Table, and YOUR unique duplication of the schematic above right, created in Fritzing, 3" wide and right-aligned.
- Media formatted and captioned photos and (no more than) 2 minute video uploaded from your personal YouTube channel. By personal, I mean you do NOT use your RSGC email or other credentials to create this channel as your material will disappear after graduation. You can't afford to lose this work.
- Reflection this is the only segment written in the first person and includes any comments you have about the concepts, the build process, any challenges you overcame and personal time-management issues you were pleased with or need to address in the future.
- Technical writing is done on the present, active voice, NOT presented in the first, second or third person. See these do and don't examples.
- Develop your own Fritzing breadboard and schematic images for inclusion in your submission and store them in your images folder. Include them in the Media subsection together with high resolution, well-composed, and formatted photos.
- Create a short (1-2 minute) video of your circuit with accompanying explanations and annotations of the components. Upload to YouTube within your own personal channel (not RSGC's) and include a full URL link in the Media section. Some of our best videos appear on our ACES' home page carousel.
- Update your Table of Contents.
- Attach your Design Engineering Report (DER.docx) to an
email to handin with the Subject: Voltage H-Bridge by
the required deadline.
Remember, your text should be developed in accordance with the recommendations for Technical Writing.