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IT DOESN'T WORK? - - DEBUGGING!

SPIN IT FAST, IN THE DARK. Sometimes your generator is working fine, but you're not spinning it fast enough. Or perhaps the dim glow of the light bulb is being missed in a brightly lit room. So, go into semi-darkness. Then spin the thing REALLY FAST. Try cranking it with an old-fashioned hand-crank drill (electric drills don't go very fast). Or try sticking a little wheel on your nail, then rub it on the spinning tire of an upside-down bicycle (don't go too fast or the bulb will burn out.)

ADD LOTS MORE WIRE. If your coil has more turns, then the bulb lights brighter. The Radio Shack wire is 200 feet long, which gives about 250 turns. If you could wind more turns on your coil, then your bulb would light up at lower magnet speed. Buy two kits of wire from Radio Shack, then use both spools of #30. Scrape the red plastic coating off all the wire ends. Then twist the end of the new spool to the end of the old one. This creates a single longer wire. Be sure to wind the extra wire in the same direction as before.

Better source of wire: buy a large "Solenoid" from a mail order company, then use Vice-grip pliers to pry open the metal bracket. Remove the the big coil, peel off the tape, and wind it on your generator. Try this one:

ELECTRONICS GOLDMINE:
12V solenoid $3.75
DON'T USE OTHER MAGNETS, use the large 2-inch rectangular magnets sold by Radio Shack, #64-1899. Or try Edu. Innovations, or CMS. They cost about $2 each, and have no holes through the center. Don't use the smaller 1 inch Radio Shack magnets. Most other magnets are way too weak and will not work unless you spin the magnets incredibly fast, at thousands of RPM (revolutions per minute.)

USING SMALLER MAGNETS
If you can't wait for mail-order of the correct magnets, instead you can use twenty of the 1" magnets 64-1879. Glue them together to form two large magnets. Here's how I did it. First I formed four magnets: I glued twenty magnets in four separate stacks of five magnets each. I used 5-minute epoxy. Before the glue hardens, adjust the magnets so the sides of each small stack are flat, and wipe off the excess epoxy. (To make the sides flat, I laid each stack down on aluminum foil, pressed them down to align the magnets, then peeled off the foil when the glue was hard.) Next, glue two of these 5-magnet stacks together side by side so the stacks are repelling each other, then hold them together until the glue hardens. That way the N pole of one stack is near the N pole of the other, and S is near S. Do the same with the other two stacks. This gives you two large magnets, each made up of ten small ones. Each magnet should have two holes on each flat pole face. Clamp the magnets on either side of your nail as usual. These aren't as powerful as the four "high energy" ceramic magnets, so you'll need twice as much wire for your generator.
DON'T USE A DIFFERENT BULB. This generator cannot power a normal flashlight bulb, it needs the special 25-milliamp, 1.5-volt bulb sold by Radio Shack. Also try using a red LED. Don't use a normal flashlight bulb, since that kind of bulb requires way more energy before it starts to glow. If you simply cannot find the Radio Shack 25mA bulb, you can use a 1.5V 40mA bulb, but add twice as much magnet wire to your coil (buy two of those kits of magnet wire.) The generator needs more than 200 turns wrapped around it. Five hundred turns is better, that way you won't have to spin the magnets so fast.

STACK THE MAGNETS SO THEY STRONGLY ATTRACT. Make sure the magnets are stacked to create two strong poles, otherwise the generator won't work. Do this: stack up all four magnets so their widest faces are clinging together. Then jam the nail through the crack in the middle of the stack. Then take this apart, and re-assemble it inside the generator in the same way.

CLEAN THE WIRE ENDS THOROUGHLY. If the generator refuses to work, inspect the spot where the wires twist together. The generator coil has a very thin red plastic coating, and you must clean ALL of this coating off the wire ends before twisting them to the light bulb wires. Also, the tips of the light bulb wires must be stripped clean of plastic. The metal wires must touch together. If there is plastic between the metal of the generator wire and the light bulb wire, the circuit will be "open" and no charge will flow.

Be sure to follow the instructions and diagrams. You MUST wind the coil so the coil goes across the side of the box which has the nail hole. If you wind it so no coil is crossing the nail-hole side of the box, then the magnetic fields won't cut across the wires, and no electric voltage will be created.

Also, don't wind the coil over the open end of the box, otherwise you won't be able to get your fingers inside to make changes to the magnet.

If you cannot spin the magnets fast enough with your fingers, try a "twist drill" or hand-crank drill. Clamp the nail in the end of the drill and spin the magnets as fast as you can. An electric drill may work too, but most electric drills don't move as fast as the hand-cranked type.

AC VOLTMETER. If you have an electronic voltmeter, set it to measure two volts AC, then connect it to the generator wires and spin the generator. The light bulb needs a bit more than 0.50 volts AC in order to light dimly. At 1.0V it lights brightly. If your generator's voltage is lower than 0.5V, you need to spin it much faster, or you need strong magnets, or you need to add lots more turns of wire.

DON'T SUBSTITUTE THE MAGNETS OR THE LIGHT BULB WITH A DIFFERENT TYPE. It needs strong magnets and a low-voltage, low-current incandescent bulb. If your generator doesn't work, check the parts again and make sure you have the right type of magnets and the right type of light bulb. Don't use fewer magnets. Weaker magnets may work in theory, but you won't be able to spin them fast enough by hand, and a high speed motor will be required in order to spin them. Don't use an LED. A red LED could work in theory, but you need at least 1-1/2 volts to barely light one up (the green or blue kind need even higher volts.) The light bulb is better because it lights up at less than 1/2 volt. (If you really must light up an LED, use the red kind, and also add about three more spools of #30 wire to your generator coil.)

Perhaps your luck is bad and you got a dead light bulb. To test it, get any new, fresh 1.5V battery (the size doesn't matter.) Take the bulb off the generator, then touch one wire form the bulb to the top of the battery and one wire to the bottom. The light bulb should light up brightly. If it stays dark, the bulb is bad.

The generator can be improved by using more turns of wire. You used only the spool of #30 wire. With more wire, the magnets don't have to spin as fast to light the bulb. Connect the thinnest of the remaining spools of wire to one end of the wire that's already wrapped, making sure to scrape the wire ends totally clean before twisting them together. Make sure to wind the extra wire in the same direction as the rest of the coil.

Or, if you want to light your light bulb REALLY bright, buy a second kit of wire, hook the second #30 spool to the coil you have already made, then wind all the wire onto the coil. Be sure to clean all the red plastic off the ends of the extra wire that you've added.


FREQUENTLY-ASKED QUESTIONS

  1. CAN WE GREATLY INCREASE THE GENERATOR'S VOLTAGE?
  2. WIND POWER GENERATOR... HOW TO MAKE ONE?
  3. HAMSTER GENERATOR?
  4. CAN WE BUILD A POWERFUL GENERATOR?
  5. CAN IT CHARGE A BATTERY?
  6. WHAT'S MY HYPOTHESIS? (For science fair?)







1. CAN WE GREATLY INCREASE THE GENERATOR'S VOLTAGE?

Increase the voltage? Sure. Just use a machine shop to carve some close-spaced iron parts. NOT! Since the Simple Generator is designed for kids to build, it only puts out about half a volt. But here's how to increase the voltage by ten times:

  1. Use large supermagnets instead of large ceramic magnets (expensive, bought via mail order.) The stack of supermagnets must be the same size as the ceramic magnet stack.
  2. Instead of winding 300 turns of wire, wind 3,000 turns. Use wire that's about 3X thinner (like #40 gauge.) But does anybody have the time and patience for this job?!!
  3. Instead of spinning the magnets at ten times per second (600RPM,) spin them 10X faster at 6000RPM. You'll need some sort of gears to step up the speed. The magnets might fly apart, so glue them and wrap them in fiberglass resin. You'll also need real bearings and not just holes in cardboard. And scrape the plastic to balance the magnets so they don't vibrate the bearings to death.

See what's going on here? Most kids can't build a generator if they tried any of the above techniques.

BUT HERE'S A THOUGHT: do ALL of the above suggestions, but do each of them only half-way. Like so.

First build a tiny generator using small supermagnets on a needle stuck through a plastic pill bottle or 35mm film can. Then wind lots of turns of thin wire on the plastic bottle (500 turns is good, but more is better. Use thinner wire, like #35.) Finally, use some "invisible gears" to step up the generator speed. Build your invisible gears like so: first build a 6-inch rotating wooden disk with a hand-crank, then glue supermagnets on the rim of the disk facing outwards. (Space them about an inch apart, with all poles facing the same way.) Place the tiny plastic-bottle generator close to the wooden disk. The magnets on the disk will move the magnets inside the pill bottle.

Now spin the disk, and the generator spins fast. And you've improved the generator in three ways. The magnets on the wheel will spin the tiny generator at high speed without touching it. The strong supermagnets in the plastic bottle will give a stronger field than the black ceramic magnets. And the extra number of turns will create extra induction. All this together should produce a much higher voltage than the Ultra-Simple cardboard generator.

You coule even build two of the pill-bottle thingies, or three or six, then somehow position them all around the rim. Hook them all in series, then turn each coil so it gives out maximum volts.

2. WIND POWER GENERATOR... HOW TO MAKE ONE?

Sticking fan blades on this generator won't work; it turns too slowly and won't light the bulb. To run a bulb, this simple cardboard generator must spin VERY VERY fast. Fan blades probably won't spin it fast enough. SO DON'T LIGHT A BULB! Instead, buy an $5 AC voltmeter. For science fairs, instead of running a light bulb, you can just display the AC voltage created by the wind power.

A wind generator might light a bulb or an LED if you wind more than 1000 turns of wire onto the cardboard. Or, you could try using two large (expensive and dangerous) supermagnets instead of four black ceramic magnets.


3. HAMSTER GENERATOR?

Can we build a hamster-powered generator? Maybe. But if you only wrapped 200 turns of wire on the cardboard, the hamster won't be able to run a light bulb. Hamsters can't run fast enough.

People have run LEDS using hamster generators with supermagnets and custom-wound coils. Or instead, just measure the hamster produced voltage.


4. CAN WE BUILD A MORE POWERFUL GENERATOR?

Store-bought electrical generators are exactly the same as motors. To see what a hundred-watt generator looks like, buy a large DC motor and take it apart. (Treadmill replacement DC motors can be found on eBay.) Or, just use a pre-built generator: spin the shaft of any DC motor, and electrical energy comes out through the motor cables.

But if you really really want to build your own professional generator, take a look at the do-it-yourself wind turbine hobbyist sites. They've designed "pancake shaped" generators which can be built without machine tools like mills or lathes. These generators work by passing some flat coils between powerful supermagnet slabs. They're designed to work at low speed, since wind turbines turn at low speed with high torque.

Note that a powerful generator requires a powerful source of "work" to spin it, such as a gasoline engine. Human muscles don't do much: if you hook a bicycle to an electric generator, an adult can produce about 50 watts, but it takes exhausting effort. Professional atheletes such as bike racers can only create a couple hundred watts (as with MacCready's Gossamer Albatross flying across the English Channel in 1979.)

  • http://en.wikipedia.org/wiki/Human-powered_transport

    5. CAN IT CHARGE A BATTERY?

    This AC generator makes the charges in the wires wiggle back and forth. It's alternating current.

    AC can light a bulb, but it unfortunately it can't charge a battery. To recharge a battery, you have to pump charges continuously THROUGH the battery and back out the other side. If you use AC, the battery just charges and discharges over and over again. The energy never builds up inside.

    Also, a rechargable battery requires more than one volt DC, while this generator creates only 1/2 volt AC. The voltage is too low because the generator turns slowly and also it doesn't have enough turns of wire to reach the battery-charging voltage. (NOTE: it would be easier to charge a supercapacitor instead of a battery, since supercapacitors don't need a minimum voltage. But they do need DC rather than AC.)

    To convert the generator to DC, just wire a diode in series. See making DC. A diode is like a one-way valve for charges. But most diodes need a bit of voltage in order to work. They won't work at all until the generator gets to around 1/2 volt. So you'll have to double the amount of wire on your generator. (Or if you're really ambitious, you could build an entire commutator assembly that fits on the shaft. A "commutator" switch is the usual way to create a DC generator. But a diode is much simpler.

    If you really want to recharge a 1.2 volt NiCad battery, add a diode to create DC. Then you must either spin the generator WAY WAY faster... or wind far more turns of wire. A thousand turns would be good.


    6. WHAT'S MY HYPOTHESIS? (For science fair?)

    Some science fairs demand that you write a "hypothesis." Real scientists simply think up questions to answer. Your hypothesis is your guess at what the answers might be. But these must be questions that your investigation can answer. Here are a bunch. Now think up some more on your own:
    1. Can this generator light two light bulbs wired in parallel? More?
    2. What amount of wire is necessary to light one bulb? How few turns?
    3. What AC voltage is created? (Get a cheap DVM digital voltmeter.)
    4. What's the maximum AC current?
    5. Can this generator drive a loudspeaker?
    6. Which types of flashlight bulbs or LEDs can this generator light up?
    7. How fast must we spin it when using two magnets instead of four?
    8. Will small cheaper magnets work better? How about supermagnets?
    9. Can this generator be converted into a motor? What volts needed?
    To create a hypothesis, just change the question into a statement. A hypothesis is a statement to be tested. If you want to find out how many bulbs this generator can light, then your hypothesis can be "THIS GENERATOR CAN LIGHT ANY NUMBER OF BULBS." Then if you find that it only can light several, you've answered your question.

    For science fairs, you'll get a higher grade if you do things with math rather than verbally. Make measurements and draw some tables and graphs. For example, you could figure out a way to tell how fast the magnets are turning. Maybe use a non-electric hand drill, so you can tell the revolutions per second. Then measure the generator AC volts for different speeds of magnets. Then plot a graph of RPM versus speed. That answers the question of maximum voltage. Or for a different experiment, always spin the generator at the same speed, but remove more and more turns of wire while measuring the volts. Then you can make a graph of number of wire-turns versus output voltage.

    Here are other websites about Science Fair Hypothesis:



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