Slashdot Mirror
Low-Budget Electronics Projects For High School?
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?
Astable multivibrator is a simple circuit, useful (flash lights at high RC values, make sounds at higher values), and teaches the basics of transistor, capacitor and resistor in a practical manner
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).
I'd start with a crystal radio, although there are designs far more compact than the one on Wikipedia. Next, perhaps a simple transistor amplifier (for which you can use the crystal radio as an audio source), then it might be time to move on to the thousand and one projects you can build around a 555 timer chip and some LEDs.
All of these are low power, low cost, and produce a visible or audible result for immediate gratification.
Mal-2
How is the Riemann zeta function like Trump rallies? Both have an endless number of trivial zeros.
I just taught a unit on electronics. We used breadboards and the 555 ic to build optical theremins. I have the entire curriculum done. contact me through /.
another option, and I just mentioned him on another story the other day... is take a look at the old forest M Mims III books. They are the books that they used to sell for a couple bucks at radioshack. You can still get them from his website, or a few other places (saw them at Fry's the other day) although they cost a few dollars more now. I started reading his books in the 4th grade and I have worked and played with electronics ever since. Each of his books have schematics (and a guide on how to read them) for many projects which can be built for a few dollars on a breadboard. I would suggest looking at something with a simple linear analog IC like a 555 or 556 timer.
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.
Obama is a twitter sock puppet
I am working on some similar projects for 11-12th graders though my budget is more in the $10 per student range. There are challenges with doing this without (a) soldering - and the risks, and (b) lead exposure. Anything intended for kids younger than 13 needs to be Pb-free to meet CPSC guidelines and avoid liability issues. For 9th graders you might need to check ASTM regs also regarding choking, entanglement, etc. It's a bit of a bear and it becomes harder the younger the kids get. I am using largely recycled components from junk cellphones and other sources (TDMA cellphones in particular are available dirt cheap and have lots of interesting projects) - http://www.larwe.com/technical/2260lcd.html documents some of my reverse-engineering though it doesn't explain why I'm doing it). A couple of interesting projects that can be made without soldering (just twisting wires) - Use a Hall effect sensor or reed switch, in combination with a light (LED, bulb, whatever) and a handful of small magnets to demonstrate making a "recording". Glue the magnets onto a strip of paper, or just use a piece of tape sticky-side up. Pull the tape past the sensor and watch the bits as they're read out on the bulb. Works best if you color say all the north poles red, so they can work out what is 0 and what is 1. - Make a light-following robot with two pager motors. There are a load of designs around, this one is not the simplest but is illustrative http://www.geocities.com/SouthBeach/6897/photovore.html If you want to liaise further, feel free to contact me using that website.
Why is this tagged 'domyjobforme'? There's a negative connotation there.
This is an (awesome sounding) teacher looking for suggestions on how to expose kids to something worthwhile.
You aren't doing his job for him until you're working for his salary, on his budget, and care enough about your students to step outside the curriculum once in a while for education's sake.
What is this, the Hipster Olympics? Do we win by looking down our noses at people?
Make all those 'dead' batteries run little torches:
http://www.emanator.demon.co.uk/bigclive/joule.htm
No sig today...