Simple Motors

This week, our class took a leap and designed our own motors. We followed a fairly simple design, which was powered by a 1.5 volt battery and a small magnet. Paper clips were attached to each end of the battery and held a coil of wire; they helped complete the circuit and connect the positive and negative ends of the battery. 

Th current flows from the battery, up one paper clip, through the wire and the motor loop and then back down the other paper clip and back to the battery. Each part of the motor functioned in a different way. The battery supplied voltage to produce a current. The coil of wire, or the motor loop as it is labeled in the diagram above, provided a pathway that allowed current to flow. The paperclips connected the wire to the batter and completed the circuit, also allowing current to flow. The magnet, placed on top of the battery, created a magnetic field that put magnetic force on the motor loop and caused it to turn.

Here is a picture of our actual motor:

We scraped one side of the wire that connected the coil to the paper clip. We did this because we needed current to flow when the loop was in one orientation and not the other. We wanted it to flow while the loop was turning in one direction without causing the loop to turn in the other direction as this would be counterproductive.

The motor turned because of the magnetic pull created by the magnet. The loop had to be vertical. This is because all the charges in the wire were moving the same way, but since the wire was coiled the current would technically be in different directions (this is important when using the right hand rule). The vertical loop felt the force of the magnet in opposite directions on the top and the bottom sides so there was a torque on both ends of the wire, causing it to rotate. If the loop was horizontal, it would not feel this force in a perpendicular way and there would be no rotation. Along the bottom of the vertical loop, the current was going to the right. (This is form the viewer's perspective in the photo above). According to the right hand rule, the magnetic field would be in the upward direction, and the force on the wire would be towards the viewer. On the top of the loop, the current would be going back the other way, the magnetic field is still in the upward direction, and the force on the wire would be in the opposite direction, away from the viewer. Since the sides of the wire are pushed in opposite directions, the wire rotates. When the wire flips and the current is still going in different directions, the magnetic field continues to act on it in this way.

Here is a picture of the hand position for the "Right Hand Rule":

My pointer finger represents the direction of the current, my middle finger represents the direction of the magnetic field, and my thumb represents the direction of the force. In order to find one of these, all you have to do is put your right hand in this position and turn it in the correct way to align with the current, force, or magnetic field given.

This motor is very small, in fact it is too small to effectively power anything. However, it can be used for educational purposes and effectively displays the basic concepts of a motor and how a simple motor is built and works. Plus it is pretty cool to watch- check out this video of ours in action!