Low-Budget Electronics Projects For High School? 364
SciGuy writes "I am a physics teacher for 9th graders. I really want to teach them modern electronics (something beyond the light bulb and battery). My hope is for a project that: 1) Is fun 2) Teaches about circuits that are relevant to their life. 3) Doesn't rely too heavily on a black box microcontroller. Individual components would probably be better. (I realize that #2 and #3 are probably contradictory. They will already be programming in my class but I want them to understand the circuitry behind modern tech.) 4) It must be as cheap as possible. Yay, public school. Unless some of the parts can be scrounged or found at home, I would probably want to keep the project around $5." What would you build?
Do they still Sell 100-in-1 kits? (Score:5, Informative)
When I was middle-school age, I had a *great time* with these kits sold by Radio Shack. They were basically a bunch of cheap electronic components fixed on some sort of board, with connections, and a bunch of wires you could use to connect the components together into different circuits. It even came with a book with like 40 or 100 (I don't remember the number, really) different circuits 'plans' for simple types of things you could do with the kit and discussions about how the circuits worked.
They cost like $10 or $20 back then (probably be $30 or $40 now, not sure though).
I would *highly* recommend looking into something like this. They are maybe a bit more expensive than you discussed, but they are re-usable and allow you to create lots of different things. Heck, you could maybe even figure out how to use multiples of the kits and maybe a few additional components to create something a bit more impressive to demonstrate to the class how larger electronics systems are created by configuring each kit into a specific type of circuit, then joining the kits together (that is, each kit becomes one 'components' of a larger system, maybe).
Nice book (Score:4, Informative)
SIMPLE, LOW-COST ELECTRONICS PROJECTS
http://www.elsevier.com/wps/find/bookdescription.cws_home/677563/description#description [elsevier.com]
A simple oscillator (Score:4, Informative)
I'd recommend a simple oscillator project. You can use it to either flash two LEDs or create tones for a speaker. It covers the use of transistors, resistors, and capacitors. The cost should be very low, and the project can be put together without solder in several different ways. Here is one article with an example.
http://www.arrl.org/news/features/2003/10/30/1/ [arrl.org]
Re:Good Luck (Score:4, Informative)
I don't think soldering irons are a requirement for this idea. Breadboards, or even springboards, would be much more appropriate, I think. Cost per student goes up, but overhead goes down.
Re:Do they still Sell 100-in-1 kits? (Score:3, Informative)
They still have these but I can't imagine them having the longevity to stand up to ninth graders. After using mine for a few months most of teh spring had become elongated and knobs lost.
Optical Theremin (Score:5, Informative)
Virtual Reality (Score:2, Informative)
Re:555 Timer (Score:3, Informative)
Getting shocked as a teenager builds character. I should know!
Re:Good Luck (Score:4, Informative)
Re:use spice (Score:5, Informative)
If you go to jameco.com you can get component grab bags, or my favorite are the component kits. For example the resistor kit has a selection of common values and a nice plastic storage thing that keeps them nice and neat. Give every student a few LEDs from a grab bag, a 555 timer chip, a battery, some jumper wire, a handful of capacitors and resistors from a couple of component kits, and the schematics to make a simple LED flasher. Then the different students will have different values of resistors and capacitors, and will get different results. Then you can time the flashing of each students project and chart the values of resistor, capacitor, and time. Explaining simple RC circuitry is a good place to start teaching somebody electronics.
The Mims books also get into digital, you could buy some simple nand gate chips and show the students all the different ways to use them, use simple push buttons for input and LEDs for output to save money. It may not be super exciting, but you could build an inventory over a couple years to do something really cool. Use TTL chips, not CMOS because the students will ruin CMOS with ESD. The possibilities are really endless. Any students who really get excited can buy a handful of parts online and build all sorts of neat stuff from those books. There are circuits for opto communications devices, a shortwave radio, a break beam sensor, you name it, its in there.
Scrounge, Circuit Bend, talk to local Radio Shack (Score:3, Informative)
Have them bring in an annoying electronic toy and have them wire a volume control into it. For that matter, have them bend circuits on all the electronic crap that surrounds us today.
Finally, talk to your later Radio Shack / Fry's / whatever, and see if you can get them to sponsor the class with some free gear and projects.
If you end up with some more coin, try a TV-B-Gone:
http://www.adafruit.com/index.php?main_page=index&cPath=20&sessid=5bf624d376f9c6c44a119200f35c990d [adafruit.com]
AdaFruit has a lot of good stuff. One thing I saw at a Make Faire was a project where you quickly build an oscillator using a paper circuit board and a pencil line drawn on a paper to have a quickie musical instrument.
Lewin Edwards (Score:5, Informative)
Light + sound + electricity = awesomeness (Score:2, Informative)
Unfortunately, I don't remember the circuit exactly, but one of the most interesting demonstrations I saw was transmitting sound from an iPod using an LED shining on a solar panel, amplified with what I believe was a single transistor and a 9-volt battery, and finally played through a speaker.
Cheap solar panels are fairly easy to come by, courtesy of Edmund Scientific and the like. The other parts can all be scavenged from various cheap sources and broken things. Incidentally, I'm also in favor of high-schoolers learning how to properly solder, as I didn't do until college.
555 ICs are God. (Score:5, Informative)
I suspect with a handful of 555 ICs, descrete circuits, ICs and switches (or just touch wires together), you can easily create a whole host of illustrative experiments that show the idea behind modern gate circuits. And I'm sure you can easily do it all for a few dollars worth of components, though unfortunately breadboards can be quite expensive. (Around $8 for a small breadboard through Digikey, though you may be able to find cheaper.)
Re:555 ICs are God. (Score:1, Informative)
The 555 is a great suggestion. I'd buy 556s for just a little more: two 555s in one IC (50pcs for $9.30 incl. shipping on eBay.)
breadboards can be quite expensive. (Around $8 for a small breadboard through Digikey, though you may be able to find cheaper.)
You'll find them for much less on eBay. Jumpwires included, too.
Re:A-stable multivibrator (Score:1, Informative)
Give the kids a 6V battery, a 7-segment display, and a 7-segment display controller such as the CD4056B. The kids should work in small groups so that they can share a breadboard.
Give them the schematic to show them how to put together the display and its controller. The kids should not have to be responsible for sifting through datasheets and making everything work- that is your job.
Each display has 4 input pins that accept a 4-digit binary number. Tell your students to experiment with the four input pins and write down what they see on the display for certain input combinations. e.g. students enter the number 0010 and the display lights up "2," or they enter 0101 and the display lights up "9."
You won't need to apply any special signal to the converter to make this work, other than a DC voltage source (the battery). No resistors, capacitors, inductors are needed for this project.
When you order the supplies for this project, order them in bulk and do NOT order from Radioshack. You should order the components from a vendor such as Jameco or Digi-key to avoid paying a 5000% markup.
This is one of the cheapest projects that actually teaches your students reasoning skills and gives them practice reporting data.
Someone probably knows a better 7-segment display driver than my old fuddy-duddy one, so if you have an idea, speak up!
Re:555 ICs are God. (Score:4, Informative)
Re:A-stable multivibrator (Score:5, Informative)
I teach middle school aged kids electronics at a local workshop, building things such as that, and I can tell you it's very doable to make projects for cheap that kids can build and understand.
The main issues that I have found is the board on which you lay out projects. Breadboards are expensive, and not permanent. PCBs don't allow kids to experiment with their own circuit designs, and unless you are going to take the time and money to let them design their own boards that might not work and then etch them, it's more trouble than it is worth. We use a more traditional breadboard concept that is just an actual, wooden board. Then we have kids use copper tacks and strips to lay down the circuitry, and then they solder things directly to that.
As other people have mentioned, soldering irons are a bit annoying, and a couple kids might get some mild burns, but as long as you don't mind the initial cost, it's totally doable.
One of the great things about the drawdio project, is it allows you to hook it up to a oscilloscope and show the kids more about sound, or hook the piezo speaker up to a computer and run some FFT software, so they can see and hear how the resistance changes the pitch.
Other things to look into are basic transistor circuits, things with opamps, counters, or things with binary to decimal or binary to seven segment LCD chips.
Light bulbs are old, make a Joule thief... (Score:5, Informative)
Make all those 'dead' batteries run little torches:
http://www.emanator.demon.co.uk/bigclive/joule.htm [demon.co.uk]
Options at $5 each (Score:3, Informative)
At $5 each, there are few options. Rainbow Kits [rainbowkits.com] are a possibility. The "blinking lights" and "1W audio amplifier" kits are both under $5.99. That's about as low as you can go.
Re:Light bulbs and batteries (Score:5, Informative)
Deciding I needed a PWM for a project, I wanted to build my own to learn about electronics...so I went to radio shack and bought their $79.99 Electronics Learning Lab.(this kit alone is HOURS of amusement and learning)...but what I learned quickly is that following the Mimms book was very wasteful...the explanations of what is happening is scant...the diagrams are great, but blinking leds and making buzzer noises just ISN'T practical to a freshman in High School(I've taught them Freshman computing and mentored them in many aspects of I.T.)...
Below are some sites I've come across searching for 'simple enough for a basic solderer' and with readily available components(strip parts out of busted old computer power supplies/vcrs/radios/etc)..
http://www.electronics-lab.com/projects/audio/023/index.html [electronics-lab.com]
something fun and useful...a 'hearing aid' =) ... the entire site is useful
http://www.aaroncake.net/circuits/ [aaroncake.net]
some things more complex...
http://sci-toys.com/index.html [sci-toys.com]
fun and educational .. some real easy stuff...and some more challenging stuff...
Hope this post ranks high enough for you to find it.
Re:A Theremin (Score:4, Informative)
The problem with the Theremin is that to make a working example based on the principle of the original (capacitive coupling between the hands and antennas changing the frequency of an LC oscillator) is actually a fairly complex project - you have to understand about how LC oscillators work, the superheterodyne principle (the pitch oscillator is the difference frequency between a fixed and variable RF oscillator), transistor amplifier principles, etc. Of course, they can be built from kits, but just building from a kit doesn't really provide any insight into the functioning of the circuit.
A project that maintains the spirit of the original but might be easier for 9th graders to get a handle on might be the optical theremin [instructables.com]. It only uses a few parts, and the basic operation of the 555 timer and light dependent resistance should be approachable for newcomers to electronics.
Re:Using the criteria ... (Score:3, Informative)
Non native speaker here. When your Dutch is half as good as my English German or French, please report back. Until then go fuck yourself AC.