THIS IS THE OLD TXT VERSION
FOR THE HTML VERSION, SEE
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Ultra-simple Electric Generator
(c)1996 William Beaty
* 4 - 1cm x 2cm x 5cm ceramic magnet, Radio Shack #64-1877 $ .99
* 1 - #30 Magnet wire 200ft, Radio Shack # 278-1345 $3.99
* 1 - Miniature Lamp, 1.5Volt 25mA Radio Shack #272-1139 $1.29
* 1 - Cardboard strip, 8cm x 30cm
* 1 - Large nail, 8cm long or more
* Misc. - Knife or sandpaper to strip the wires
* Misc. - tape
* Optional: hand drill or electric drill
This is an electric generator which is capable of lighting a tiny
light bulb. The generator is made up of a hollow-ended cardboard box
with a nail through the center, many turns of wire wound around the
box, and four magnets clamped around the nail. When the nail and
magnets are spun fast by hand, the little light bulb lights up dimly.
First make the hollow-ended box. Score the cardboard strip like so:
___________________________________________________________________
| 8cm | 3.5cm | 8cm | 3cm | 7.5cm |
| | | | | |
| | | | | |
| | | | | |
|8 | | | | |
|cm | | | | |
| | | | | |
| | | | | |
| | | | | |
| | | | | |
|________________|________|_________________|_______|_______________|
_____8_________
_|______________ \
|\ 7 | \ 3.5
|3\ | \
| \_____________|___\
| | 8 |
| | |
| | |
| | | Fold it like this and tape
| | | it securely.
| | |
| | |
| | |
| | |
\ | |
\|__________________|
_______________
_|______________ \
|\ | \
| \ | \
| \_____________|___\
| | | Use the nail to poke a hole perfectly
| | | straight through the center of the
| | | box, going through both sides and all
| | (hole) | three layers of cardboard. Then pull
| | | the nail out and use it to widen all
| | O | the holes slightly, so when you put
| | | the nail back through, it will be a
| | | bit loose and able to spin.
| | |
\ | |
\|__________________|
Pick the spool of number-30 magnet wire from
_______________ the kit of spools. This is the thinnest.
_|______________ \ Tape one end of the number-30 magnet wire
|\ | \ to the side of the box, then wind all of
| \ | \ the wire onto the box as shown. It's OK
| \_____________|___\ to cover up the nail hole. Pull the taped
| | | end of the wire out, then tape down both
\ | | of the wires so you have about 10cm
\\ | | of wire sticking out.
\\\====================|
\\\====================/___
|\\====================/ \
-----+-\====================/ \
/ | ==================== \
/ | | | \ Use sandpaper or the edge of a
| \ | | | knife to scrape the thin plastic
| \|__________________| | coating off 2cm of the wire ends.
| Remove every bit of red coating,
so the wire ends are coppery.
_______________
_|______________ \
|\ | \
| \ | \
| \_____________|___\ Spread the wire away from the
| | | nail hole and tape it in place.
\ | | Stick the nail back through the
\\ | | holes and make sure it can spin.
\\\====================| Take your four magnets, stick
\\\========---=========/___ them face to face in two pairs,
|\\========(\\)========/ \ Then stick the two pairs inside
-----+-\===========(_)======/ \ the box and on either side of the
/ | ==================== | nail so they grab the nail. Push
/ | | | | them around until they are some-
\ | | | what balanced and even, then spin
\|__________________| | the nail and see if they turn
freely. If you wish, you can
stick 2cm squares of cardboard
between the magnets to straighten
them, and tape the magnets so they
don't move around on the nail.
_____ magnets
|_____| _____________
|_____| |_____________| 2 magnets
=================|| NAIL |_____________|
|_____| ______O______
|_____| |_____________| 2 magnets
|_____________|
SIDE VIEW OF THE
NAIL AND MAGNETS VIEW FROM THE END
Make sure that the ends of the generator wire are totally cleared of
red plastic coating. If there is a bit of plastic left, it can act as
an insulator which turns off your light bulb circuit.
Twist the scraped end of each generator wire securely around each wire
from the small light bulb. One generator wire goes to one light bulb
wire, the other generator wire goes to the other light bulb wire, and
the two wire connections should not touch together.
.
Spin the magnet REALLY fast and the bulb will light dimly. If it
doesn't work, try spinning it in a dark room so you don't miss the dim
glow. If needed, adjust the position of the magnets so they don't hit
or scrap the cardboard. This thing has to spin *fast*, and if the
magnets whack the cardboard and stop, you won't see any light. (IF IT
DOESN'T WORK, SEE "DEBUGGING" BELOW)
Once you get it to work, try clamping the point of the nail into the
chuck of a hand-crank drill. Spin the magnets fast with the drill and
the bulb will light brightly. Don't go too fast or you'll burn out the
bulb, or fling magnets all over the room. You can try this with an
electric drill as well, although electric drills don't spin as fast.
Note: your generator produces Alternating Current, not Direct Current.
The output voltage is about 2 volts max, so there is no shock hazard
at all.
_________________________________________________________________
HOW IT WORKS
All metals contain a movable substance called "electric charge". When
a circle of wire surrounds a magnetic field, and the magnetic field
then changes, a circular voltage appears and forces the movable
charges in the wire to rotate around the circle. In other words,
moving magnets create electric currents in closed circles of wire.
This is a basic law of physics, and is the basis of electric
generators. When the charges within the wire are passed through a thin
light bulb filament, their speed greatly increases. The fast-moving
charges heat the filament by a sort of electrical "friction". They
also heat the wires of the generator a bit, but since the generator
wires are so much thicker, most of the heating takes place in the
light bulb.
OTHER THINGS TO TRY:
Disconnect one wire from the light bulb. Spin the magnet. While still
spinning the magnet, have a friend touch the wires together so the
bulb lights up again. Is the nail still as easy to spin? Keep spinning
the magnet while your friend connects and disconnects the bulb. Feel
any difference in how hard you must spin the nail?
SO WHAT?
When you crank the generator and make the lightbulb turn on, you are
working against electrical friction in order to create the heat and
light. You can FEEL the work you do, because when you connect and
disconnect the bulb, it gets harder and easier to crank the generator.
Think of it like this. If you rub your hands together lightly, the
skin stays cool, but if you rub your hands together hard, your skin
gets hot. It's hard to heat skin, it takes work. And it's hard to heat
the lightbulb filament, it takes work. You twist the generator shaft,
the generator pushes the wire's charge slowly through the tiny
filament, and if you don't keep spinning the magnet, the magnet will
be slowed quickly.
FEEL AN ELECTRON
When your hand spins the magnet, you can feel the extra work it takes
to light the bulb. This happens because your hand is connected to the
flowing charge in the bulb, and when you push on it, you can feel it
push back on you! Your hand twists the nail, the nail spins the
magnet, the magnet pushes the invisible magnetic fields, the fields
push the movable charges, the charges flow slowly through the light
bulb filament, and the tiny filament causes friction against the flow
of charge and heats up. But then the reverse happens! The charge can't
move much because of the tiny filament, so it resists the pressure
from the magnetic fields, which in turn resist the pressure from the
magnet, which resists the twisting pressure from the nail, which
resists the twisting pressure from your fingers. So, in a very real
way, you can FEEL the electrons in the light bulb filament. When you
push them, you can FEEL their reluctance to move through the narrow
filament!
A CHALLENGE: there is a simple way to convert your generator into a
motor. It involves putting some insulating paint on part of the nail,
then using a 6V battery and using the generator wires as "brushes"
touching the nail. Can you discover the trick?
WARNING: Keep the magnets away from computers, disks, color TV sets,
and wallets and purses containing credit cards. Try this: Keep the
generator far from your color TV, turn on the TV, start spining the
nail so the magnet is spinning fast, then bring the generator about
2ft away from the TV screen. DON'T BRING IT CLOSER!!! Keep spinning
the magnets, and you'll see a cool wobbling effect in the TV picture,
along with some color changes. The field from the magnet is bending
the electron beam that paints the picture on the screen. Be careful,
if you bring the magnet about 15cm away, the iron sheet inside the TV
picture tube will become magnetized and the distorted colors will be
permanent.
DEBUGGING
If the generator refuses to work, inspect the spot where the wires
twist together. The generator wire has a very thin red plastic
coating, and you must clean all of it off the wire ends before
twisting them to the light bulb wires. 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.
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.
Don't substitute the magnets or the light bulb with a different type.
Don't use fewer magnets. Weaker magnets may work, but you won't be
able to spin them fast enough by hand, and a motor will be required.
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 the wire that's there, making sure to scrape the
wire ends well 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 #30 spool to the coil you have already made,
then wind all the wire onto the coil.
_________________________________________________________________
Mail me at: billbeskimo.com
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