Bardia BaheriBardia Baheri

Rotary High Voltage MotorRotary High Voltage Motor

Physics projectPhysics project

How to build?How to build?

In order build this rotary motor we will need two cans of coke and In order build this rotary motor we will need two cans of coke and a plastic plate a pen and a Styrofoam cup and some wire and a plastic plate a pen and a Styrofoam cup and some wire and some aluminum.some aluminum.

Using the safe high voltage power we get by placing a sheet of aluminum foil on the face of a television or computer CRT screen, it spins a Styrofoam cup around at a respectable speed.                                                                                       

                              

                                                                                          

To build this motor, these materials are To build this motor, these materials are needed: needed:

Two empty soda cans. Two empty soda cans. A Styrofoam cup.A Styrofoam cup. A ball-point pen. A ball-point pen. A couple square feet of aluminum foil. A couple square feet of aluminum foil. Two paper clips. Two paper clips. A hot glue gun. A hot glue gun. Cellophane tape. Cellophane tape. Two wires. Two wires.

We start by spreading glue over the outside of the Styrofoam cup. We start by spreading glue over the outside of the Styrofoam cup. Put just a thin layer on, so it dries quickly. Before it dries, cover Put just a thin layer on, so it dries quickly. Before it dries, cover the cup with aluminum foil. Press the foil flat against the cup, sothe cup with aluminum foil. Press the foil flat against the cup, so

With a sharp knife, neatly cut a half inch strip out of the foil on With a sharp knife, neatly cut a half inch strip out of the foil on both sides, so you have two patches of foil, one on each side of both sides, so you have two patches of foil, one on each side of the cup, that do not touch one another. the cup, that do not touch one another.

any wrinkles are pressed down.any wrinkles are pressed down.

The cup is going to be spinning upside down on the point of a ball-The cup is going to be spinning upside down on the point of a ball-point pen. To keep the cup centered on the pen-point, and to point pen. To keep the cup centered on the pen-point, and to provide a low friction bearing, we need to glue something hard to provide a low friction bearing, we need to glue something hard to the center of the bottom of the cup, something that has a little the center of the bottom of the cup, something that has a little dimple in it to sit on the pen-point.dimple in it to sit on the pen-point.

                               

                                                                                         

The end of the pen is glued in the exact center of the bottom of The end of the pen is glued in the exact center of the bottom of the cup, as shown below. Note the little dimple.the cup, as shown below. Note the little dimple.

Next we make the stand for the motor. Start with a paper plate, Next we make the stand for the motor. Start with a paper plate, and glue the bottom of a ball point pen to the exact center of the and glue the bottom of a ball point pen to the exact center of the plate, so the point stands straight up .plate, so the point stands straight up .

Glue the two soda cans upside-down onto the plate, leaving Glue the two soda cans upside-down onto the plate, leaving enough room between them for the Styrofoam cup to rotate easily enough room between them for the Styrofoam cup to rotate easily without touching either can. There should ba about a half of an without touching either can. There should ba about a half of an inch gap between the cup and either can.inch gap between the cup and either can.

Straighten two of the bends of a paper clip (leaving one end bent Straighten two of the bends of a paper clip (leaving one end bent as in the photo below) and tape them to the cans as shown. Bend as in the photo below) and tape them to the cans as shown. Bend the wires into an S shape, leaving enough room to place the cup the wires into an S shape, leaving enough room to place the cup on top of the pen.on top of the pen.

Here is a picture of the stand:Here is a picture of the stand:

Now put the cup upside-down onto the pen-point. Make sure the Now put the cup upside-down onto the pen-point. Make sure the dimple fits onto the pen-point. The wires should be about a half dimple fits onto the pen-point. The wires should be about a half inch away from the cup, with the point being closest to the cup. inch away from the cup, with the point being closest to the cup. Nothing should be touching the cup except the point of the pen.Nothing should be touching the cup except the point of the pen.

Connect a wire from the can on the right to a large sheet of Connect a wire from the can on the right to a large sheet of aluminum foil pressed against the screen of a TV.aluminum foil pressed against the screen of a TV.

Connect another wire to the left can, and connect the free end to Connect another wire to the left can, and connect the free end to

a good ground connection, such as a cold water pipe, or the metal a good ground connection, such as a cold water pipe, or the metal frame of a computer. In a pinch, you can just hold onto the free frame of a computer. In a pinch, you can just hold onto the free end, since your body is a good enough ground for this little motor.end, since your body is a good enough ground for this little motor.

When you turn on the television, the foil will pick up a high When you turn on the television, the foil will pick up a high

voltage, and the little motor will start spinning. As it slows down, voltage, and the little motor will start spinning. As it slows down, turn the television off, and the motor will get another kick, and turn the television off, and the motor will get another kick, and spin faster. You can keep this up as long as you feel like turning spin faster. You can keep this up as long as you feel like turning the TV on and off. the TV on and off.

How does it work?How does it work?

One of the cans which is on One of the cans which is on the right is charged with high the right is charged with high voltage from the face of the voltage from the face of the TV when the TV turns on (The TV when the TV turns on (The picture shows the electrons picture shows the electrons on the surface of the TV). This on the surface of the TV). This means that the electrons are means that the electrons are pushed onto the can with a lot pushed onto the can with a lot of electrical "pressure". The of electrical "pressure". The electrons all have the same electrons all have the same negative charge, and so they negative charge, and so they repel one another.repel one another.

Electrons shown in blue color.Electrons shown in blue color.

At the point of the wire the electrons are most crowded, and so there is the highest At the point of the wire the electrons are most crowded, and so there is the highest pressure. It is so high that the electrons can get pushed right off the wire, landing on pressure. It is so high that the electrons can get pushed right off the wire, landing on the air molecules near the wire. These air molecules are now also negative, so they the air molecules near the wire. These air molecules are now also negative, so they are repelled by the extra electrons in the wire. They move away from the wire, and hit are repelled by the extra electrons in the wire. They move away from the wire, and hit the aluminum foil, where the electrons leave the air molecules and collect on the foil. the aluminum foil, where the electrons leave the air molecules and collect on the foil.

The electrons on the foil are repelled by the can The electrons on the foil are repelled by the can on the right, which still has an excess of electrons. on the right, which still has an excess of electrons. The electrons in the can on the left are repelled by The electrons in the can on the left are repelled by the electrons in the foil, so they move away from the electrons in the foil, so they move away from it, leaving behind the positively charged nucleus, it, leaving behind the positively charged nucleus, which attracts the electrons in the foil. With the which attracts the electrons in the foil. With the right can repelling, and the left can attracting, the right can repelling, and the left can attracting, the foil is pulled to the left, and the cup rotates.foil is pulled to the left, and the cup rotates.

Electrons shown by blue and positive charge shown by red color.Electrons shown by blue and positive charge shown by red color.TV (power source) is located on the right and the left can is grounded.TV (power source) is located on the right and the left can is grounded.

Half a revolution later, the charged foil is next to the wire that is Half a revolution later, the charged foil is next to the wire that is attached to the ground. The electrons from the foil charge the air attached to the ground. The electrons from the foil charge the air around the wire, and the electrons can move from the foil through around the wire, and the electrons can move from the foil through the air and the wire, to the ground. This leaves the foil uncharged,the air and the wire, to the ground. This leaves the foil uncharged,

so it is not repelled by the can on the right as it moves by. And so it is not repelled by the can on the right as it moves by. And this whole process makes the cup to rotate.this whole process makes the cup to rotate.

The EndThe End