DEBUGGING

DON'T USE DIFFERENT PARTS. This generator cannot power a normal flashlight bulb, it needs the special 25-milliamp, 1.5-volt bulb sold by Radio Shack. 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 of wire 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.

DON'T USE OTHER MAGNETS, use the large 2-inch Radio Shack rectangular magnets #64-1899. 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.

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. Two hundred feet of wire gives about 250 turns wound on the cardboard. 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. That gives you over 400 turns. (The more turns of wire in the coil, the brighter the bulb will light.) Be sure to clean all the red plastic off the ends of the extra wire that you've added.

FREQUENTLY-ASKED QUESTIONS

A rechargable battery requires more than one volt DC, while this generator creates half a volt AC. It would be easier to charge a supercapacitor, since supercapacitors don't need a minimum voltage. But they do need DC.

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 to work. 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.

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 a 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 flashlight bulbs or LEDs can this generator light up?
7. Will small cheaper magnets work better? How about supermagnets?
8. 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:

• What is a hypothesis?
• Writing the Hypothesis
• Form Your Hypothesis
• Projects basics

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