I am trying to make a hand crank generator with my son. We have magnets and copper wire, how do we do it?

Question

Is the coil wound with 2 wires hanging out if so which is positive and which one is negitive I am trying to make a hand crank generator with my son. We have magnets and copper wire, how do we do it?

Answer 1

The problem with a simple generator is that it will be difficult to detect the weak output. Generators are rather precision devices to be efficient, even those "Science demo" types that light up a small bulb are engineered well.

Forget about generating Direct Current (a + and a - output) that requires  commutator brush set or an external rectifier. You might be able to make a simple device that would generate an AC voltage you could detect with a speaker or earphones. Just make a coil of wire (100 turns ?) and figure out a way to spin the magnet within the coil. The magnet should rotate across the coil, not in line with it, and the coil should be wound to fit the size of the magnet. You will need a gear or pully to spin the magnet fast in order to generate an audible sound.

There are some electric science kits for kids and parents. Try Edmund Scientific at www.scientificsonline.com. Good luck!

Answer 2

Yes, but voltage at the ends of  "2 wires hanging out"

will alternate: the end of each wire will go from "+ to -"

and "- to +" with a sine wave magnitude-->like the

voltage in your home.

I'm assuming you realize that "the two ends" need

to be attached to the sliding contacts on your

crank device. Necessary, if you plan on measuring the

voltage or using the energy.

Wrap your wires "like rectangles-->better" in a clockwise

direction.

The more warps the better: more voltage

Add some tape to hold the wraps.

place each magnet so that their field's go like this:

south-------------------->north

---------------------------->

---------------------------->

---------------------------->

---------------------------->

---------------------------->

The two ends:   ^      ^ "sticking out"

The long side of the rectangular coil should be perpendicular to the field above.

Turn as fast as you can! May need a micro-volt meter

to measure

Have a good day.

Edit: Make sure you use insulated magnet wire: Radio shack

Thin gage should be ok. Wrap around the edge of some rectangular form like plywood or iron.  Need anymore help, let me know.

Answer 3

I seem to recall seeing an old boy scout book with a motor or generator made out of paper clips and wire etc.  Might be worth searching for.

The tricky part is, you won't have positive or negative - you'll have alternating current.  As the N pole of the magnet swings past the coil, you'll get one wire +, and the other -.  As the S pole swings past, the wires will change polarity.  What used to be + is now -, and what used to be - is now +.

Note that a magnet sitting still beside the coil won't create electricity - something has to be changing or moving.

This is okay if you are trying to light a small flashlight bulb.

If you are trying to replace a battery in some other device, you might need at least 1 diode in "series" to convert the AC to DC.

Picture an analog clock sitting on a dinner plate.  Pretend the second hand is a bar magnet, and the dinner plate is a coil of wire.  This is the configuration you'll want to aim for.  Of course, a more advanced system could include a second plate (coil)  on top of the clock, parallel to the bottom coil, and connected in series.