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The Electric Motor is starting to look more and more like the direction in which the future of automobiles is heading. Not only are they more efficient than the internal combustion engine, but they also produce less pollution in terms of our atmosphere and in terms of sound pollution. These engines are also able to accelerate the car almost uniformly giving them a safer and stable ride.

Some examples of electric cars use a gearbox to control their speed. Different gear ratios give the car different top speeds. In a four-speed gearbox, for example, the first gear would be the smallest and not allow the engine to travel as fast as the second gear would due to its larger size. The third gear would then allow an even higher top speed and so on until in the fourth gear it reaches its final top speed.

The motor works using an Electromagnet and a Field magnet. The power from the Battery is sent to the Brushes. The Brushes are usually two pieces of spring metal that simply make contact with the Commutator by brushing against it when it spins with the Armature. The Commutator wraps around the Axle and is attached to it through two separate pieces of metal. Each piece of the Commutator is connected to a piece of wire that wraps around the Armature or Rotor, in a direction away from the Axle. Once the wire gets to either end of the Armature, it goes straight back down and connects with the wire from the other end.

With all of this connected to the Armature, it creates an Electromagnet. Electromagnets have a very simply principle behind them, by running an electric current through a wire, you create an artificial magnetic field that can be turned on and off by stoping the flow of electricity. A field magnet is a permanent magnet that sits around the Electromagnet (Armature) inside the motor. This is what causes the motor Armature to spin.

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Figure 1 - This image shows the armature within its field magnet

While the Armature is spinning, the Brushes, having their own charge, change the charge on each end of the Armature. When the Commutator spins around and the brushes swap around and connect to the opposite side of the Armature, it swaps the polarity of each end of the Armature (Electromagnet). This then causes the Armature to spin around and seek the other end of the Field magnet. This process is a chain reaction that keeps the Armature spinning until the electrical current is stopped.

The efficiency of an electric motor is approximately 95%. This is opposed to an Internal Combustion engine which has an efficiency of approximately 20%. The electric motor is efficient due to the fact that there is only one type of change in energy. The electric engine only has to convert electrical energy from the power source, into kinetic energy of the armature which spins the wheels of the vehicle directly.

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