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Newbie in need of Science Fair Help...Please

Discussion in 'Electronic Basics' started by Gill, Oct 13, 2004.

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  1. Gill

    Gill Guest

    Hi, I'm hoping someone out there can help me. I have a seventh grade son
    who must do a Science Fair project. He has chosen to do a project based on
    "Alternative Energy". His goal is to power his GameBoy using some form of
    power other than batteries or electricity. Any and all alternative energy
    sources are being considered.

    The problem is that we have been unable to find any information that will
    help us to achieve his goal. We have been to the library a number of times;
    we have checked the book store; stopped in at Radio Shack; and have surfed
    the Internet - all without luck. We are able to find books and websites
    about Alternative Energy but they all just tell about what other energy
    sources are out there (water, solar, static, etc.) but not information on
    how to harness that energy and convert it to power for a particular device.

    I have read article refering to a man who converted his TV to be powered by
    in kids pedaling a bicycle but I can't find a "how to" for that either.
    We've all seen the in Science books about powering a digital clock or
    flashlight battery with a potato or lemon...could a series of potatoes
    supply the 3 volts needed? We have tossed around a number of possible
    approaches, including: potatoes; bicycle power; solar power; hand crank;
    possible incorporation of a car alternator; and many more.

    Any information on where to find instuctions for harnessing and converting
    alternative energy (or any other insight you might have) would be very much

    Thank you,

  2. A Game Boy is likely to not like unregulated power, so you may want to
    consider that. A diode bridge, a filter capacitor, a zener diode, and
    the appropriate dropping resistor would possibly do the trick in the
    right configuration. They may be internally regulated, though...maybe
    someone here knows if that is the case.

    I don't know what the voltage requirement is (6 VDC?). Perhaps some
    kind of miniature windmill turning a generator, or motor connected in
    reverse, driven by a variable fan? Hmmm...that may be out, as
    something is needed to drive the fan...some kind of hand-cranked or
    foot-cranked affair, maybe.

    My son just informed me that a Game Boy is 2 cells/3 VDC...that's good
    news, because it puts it closer to the range that the fruit and
    vegetable battery can possibly provide, although I don't know if
    you'll get enough power without a fairly substantial series/parallel
    setup, and .

    I'll try to check into this a bit more later; it looks like you've
    done your share of research, so it isn't like you're asking for
    someone to do the project for you (which would be frowned upon most
    times at least).

  3. Rich Grise

    Rich Grise Guest

    Design a VR suit that's coupled with cranks and levers and pushrods and
    stuff to a generator, so the game is powered by the player's own movements.


    Good Luck!
  4. CFoley1064

    CFoley1064 Guest

    Subject: Newbie in need of Science Fair Help...Please
    Hi, Renee. Glad to help.

    First of all, voice of experience. Don't use the Nintendo -- it's too
    expensive. You don't want to put anything in your kid's science project that
    you can't afford to risk by smoking, losing, or having stolen. The Game Boy
    qualifies on all three counts, especially the last. In addition, Game Boys
    require a two part adapter -- one part replaces the battery, and the second is
    the AC adapter. You'll have to buy one of those to get to the point that you
    can apply power. Looks like too big of an investment. Go to Wal-Mart and get
    one of those $10.00 LCD screen handheld games instead. Make sure they've got a
    few in stock so you can buy two. But before you do, determine what kind of
    alternative power you want to do, and how many batteries you're trying to
    replace. Most of these handheld games require two (3V), 3 (4.5V), or 4 (6V) AA
    batteries. By the way, it also might help while you're at Wal-Mart to get one
    of those cheapie $10.00 digital voltmeters. You'll need it for the project,
    because it will help you to get data (necessary for an A in any 7th grade
    science project) as well as providing a check on your power sources before you
    plug anything in. Remember, connecting power backwards with any of these
    things usually means you let the smoke out.

    The lemon idea with pennies and zinc mail is interesting. You're creating a
    battery cell with a potential of about 0.9V. The problem is, the cell is only
    capable of providing a couple of mA before it bogs down. Most of that has to
    do with the surface area of copper and zinc which comes in contact with the
    acetic acid of the battery. Let's say you've got 3 lemons in series, which
    would make a 2.7V battery. You would then choose a two battery handheld LCD
    game, connect your batteries together with small alligator clips, and hook your
    lemons battery up to the + and - battery clips inside the game with the free
    ends of the test leads (view in fixed font or M$ Notepad):

    | Game |
    | Connect Lemons to Battery |
    | Clips Using Gator Clips |
    | |
    | + - |
    | |
    | |
    .-----' '--------.
    | |
    | |
    | .-. .-. .-. |
    '-----( L )--( L )--( L )------'
    '-' '-' '-'
    created by Andy´s ASCII-Circuit v1.24.140803 Beta

    If the battery bogs down, you might have a problem. One way to solve it is to
    put a couple of 3-lemon battery strings in parallel. Make sure you've got the
    polarity straight.

    Another option would be a bike generator. You can get these inexpensively from
    many sources. One good source is the retired guy down the street who fixes up
    and sells used bikes as a hobby. He's probably got a couple of these
    generators in his junkbox, and will be willing to part with them for a couple
    of bucks and a six of his favorite malt libation. If you've got an exercise
    bike lurking around, you can hook up the bike generator to provide a power
    source. You may come up with another way to crank the generator besides
    spinning on a bike tire sidewall, but that's up to you. Bicycle generators
    usually put out AC (alternating current). They will typically produce 6 Volts
    AC at up to 1/2 Amp. You won't need anywhere near that much current, so you're
    OK there. What you will need is a way to rectify that power, and regulate it
    so it has a steady voltage like a battery. This is one which is particularly
    good for a 6V toy (4 AA batteries) or 4.5V (3 AA batteries). In order to get
    safe DC power from the generator AC, you will need something like this (view in
    fixed font or M$ Notepad):

    | | ____
    | | D | | +
    | o-----o--->|---o---------o--|7806|--o--o
    | Bike | | | | |____| |
    | Generator | | D | | | |
    | | '---|<-----. +| | +|
    | | | | --- | --- 6 Volts
    | | D | | --- | ---
    | | .--->|---' | C1| | C2|
    | o-----o | | | |
    | | | D | | | |
    | | '---|<-----o-------o----o-----o--o
    '-----------' -

    created by Andy´s ASCII-Circuit v1.24.140803 Beta

    The 6 VAC is retified by the 4 diodes labelled D. Charge is stored on
    capacitor C1 such that the DC voltage input to the voltage regulator will be
    near the peak DC produced by the generator (about 9VDC). The 7806 voltage
    regulator drops and smooths out the voltage to 6VDC, with cap C2 required to
    ensure stability of the regulator. I would choose 1N5819 diodes for D, a
    1000uF 25V cap for C1, and a 10uF 25V cap for C2. All of these, along with the
    7806 regulator and perfboard to put the components on, are available from or Radio Shack. E-mail me if you need help getting the components
    together. Please put "Science Project" in the heading, or it will get sent to

    The above circuit is good for a 4 battery device. If you want a 3 battery
    device, choose a 7805 regulator in place of the 7806. That will give you 5VDC,
    which is close enough to 4.5V for what we're doing here.

    A third option is solar power. Radio Shack has a 6V 50mA solar panel for $16
    USD which will fill the bill perfectly for a 4-battery device. You just hook
    up the red wire to the + and the black wire to the - battery terminals on the
    battery clips of the toy. Simple and straightforward.

    For your project, you might want to try to find a 3V toy and go with the lemon
    battery, as well as the 6V toy and go with the generator and rectifier/voltage
    regulator. I'm not sure what kind of data you can get from the solar cell
    that's useful in a science project. Remember, by 7th grade they're supposed to
    be able to do a paper with hypthesis, data, and writeup. With a cheapie
    voltmeter you will be able to get voltage readings, and you might be able to
    get something of a DC current reading, too. That will be enough for what you

    When doing these things, it's really good to teach the First Axiom Of
    Engineering Projects, taught to me by a wise engineer years ago:

    *** HURRY EARLY ***

    Hopefully this isn't due tomorrow next week (unfortunately, that was the case
    with both of my kids). Deciding what to do and getting the components together
    is a good first step, and should be done as soon as possible.

    Good luck
  5. Gill

    Gill Guest

    Thank you Tom for your help. My husband thought that a diode would need to
    be used...he seemed to remember that bit of information from his highschool
    days. Yes, we've been trying to do research...that's why it has been so
    frustrating not to have made more progress to this point. It's great
    getting different perspectives from others...we appreciate the feedback and

  6. Gill

    Gill Guest

    Well Rich...we like the VR suit idea...unfortunately if we haven't been able
    to find the needed info for harnessing alternative energy, I guess I'm not
    too hopeful for finding VR suit instructions...

    Maybe we can save the VR idea for my son's highschool years.

    Thanks :)

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