Part of Unit: Personal Computers and Components
Lesson Plan Overview / Details
Power supplies can often be an overlooked component to a personal computer, but its an important one! This lesson teaches students about the different kinds of power supplies, how to replace one in the computer, and creating a guide to buying and replacing a power supply in a computer.
- depends of in-class research allotted
- 3 - 5 Class Periods
California Career and Technical Education Standards
- ED.E.E7.2 Install and configure the main computer hardware and software components.
- ED.E.E7.4 Know the function and interaction of basic computer components and peripherals.
California Academic Content Standards (Reinforced)
Objectives and Goals
- Students will learn what a power supply is and its function in the computer system.
- Students will learn the pin layout for a power supply connector.
- Students will learn proper installation and preventative maintenance of a computer power supply.
Activities in this Lesson
- Start Me Up - Hooks / Set
Display the cartoon in class as the students enter. They will get the idea that today's lesson is going to have something to do with power or electricity. You can discuss with them why power is important, how it affects their everyday life. How long have they ever had to go without power? How well can they function (eat, entertain themselves, shower, etc) without power?
Video - show video on testing a power supply with an inexpensive Power Supply Tester that can be picked up on ebay or a PC tool website like newegg.com. The video shows a simple way to diagnose a bad power supply, a valuable tool any PC Repair tech should have in their pocket.
Remind students that any time they are dealing with power supplies, they are working with electricity, and they must take all the proper safety precautions.
- Don't forget me - Lecture
This is a vital but often overlooked component in the computer system. The computer will not function without it! Since the previous section of this lesson showed students an easy way to test a power supply, students may not think it is very important to know the details of how a power supply works, but its not as simple as just plugging in a tester and replacing bad PSU's. For one, they need to know more for the A+ certification test.
In this section, you are going to tell your students the basics of what a power supply is and its role in the computer system. Include the following items:
-- What is a power supply, how does it function in computer, turning on/off (physical switch and software signal, role power button plays now)
-- Type of power supplies, AT, ATX, types most commonly used now
-- Warnings of working with power supplies (safety issues)
-- Cleaning the power supply (compressed air, which way to blow air, having computer off)
-- Voltages/wattage rating on power supply
-- How to detect problems (smells, smoke, noise, spontaneous rebooting, heat)
It is helpful if you have power supplies that can be passed around and handled by the students as you discuss and describe these items. Have open computers so they can see where the power supply is installed in the computer and show them the connectors and how other parts of the computer are connected. Safety is an important issue, review with them safety rules of working with electricity, what they should and should not touch, whether they should attempt to open the power supply and repair vs. buying a new one.
- Connectors and pins - Demo / Modeling
Have connectors available for students to look at while you are reviewing the material. Have students create a guide to the pin layout. Have them write it out on paper. Recreating it in Excel is very easy, students can add labels and colors easily, save the diagram and have it available for study and reference.
Good website that shows pin layout:
- Practice Time - Lab / Shop
Have the room set up with equipment so students can practice working with power supplies.
Station 1 - installing/uninstalling power supply in the computer
Station 2 - cleaning the power supply (finding some old, really dusty computers for this really helps get the point across) Have cans of compressed air available for students to use.
Station 3 - identify pin connectors (give students blank chart that they have to fill in)
Station 4 - set up some malfunctioning power supplies (that are not safety hazards) for students to see/hear what symptoms might arise if the power supply is going bad
Let the students work in pairs or small groups going around to each station and getting hands-on practice. Make sure to monitor the class and their use of tools and compressed air and that they are practicing safety first. Don't let them actually plug in the computer to outlet and turn in until you have checked their work and are supervising.
- Does it work? - Closure
If you are able, purchase a power supply tester for students to actually see one, hold it, and try it out. This works great if you have a document camera and can project the tester on a screen for the whole room to see. Otherwise if you have a small class, they can gather around a work area and you can demonstrate the tester.
Inexpensive testers can be purchased on the internet, try ebay (I've seen one's in the video for $5) or amazon at various prices.
Review with students what lights should come on with a good power supply. Test some bad PSU's and see if they can hypothesize what will happen. Do a few things like have the power cord unplugged from wall or have the switch on the power supply turned off, see if students notice these things.
Buyer's Guide to Power Supplies
- Assessment Types:
Develop PowerPoint presentation titled “Buyers Guide to Power Supplies”
Have students research on the internet and use information from class activities to create a presentation with the following slides:
- Title slide
- What power supply does in a computer
- Different types of power supplies
- Wattage ratings on power supplies
- Noise or no noise
- Power efficiency
- Determining the right type and number of connectors
- Stores that sell power supplies (get pictures and prices)
- Steps to changing the power supply (including safety)
- Ending slide
Include graphics, slide transitions, animations as appropriate. Spelling/grammar/capitalization counts!
Grading is based on the information/accuracy of presentation, as well as design of presentation. I put more weight on the information and the research the students did, than the actual design, depedning on the level of students. If these are students that have previously taken an Office class and should be aware of how to properly design a presentation, then I make the info/design weights more equal. Since this is their assessment of understanding the lesson, I make the total score a significant amount. Allow 2-3 class periods for research and design. Presentations can be made in class, if you have time, posted on websites or common drive where students can view each other's work.