Electric Motors

   Electric motors are everywhere but most recently electric motors have been transitioning into the automotive world with battery powered cars and cars that use less fuel than a normal composition engine but how does an electric motor actually work? An electric motor uses electric energy from a battery to make mechanical energy which makes the motor move. Their are two ties of electric motor an AC (alternating current) and a DC (direct current) the difference is that the DC motor ( the one we built for the project)  has a commutator and a set of brushes while an AC motor has no brushes or commutator and goes faster as well as has a better life expectancy. 

An AC Motor

    

A DC Motor

I am going to be focusing on how a DC motor works but an AC motor works around the same way. First two wires are set up that connect to the electrical source (battery) when it is turned on a current is sent through one wire into a brush which then transmits the current to the commutator ( a cylinder on the shaft that has two metal metal strips on it at opposite points). The brush touches on of the metal strips lets call them them the commutator strips A and B. Commutator strip A is also connected too the armature which when current flows through it creates and electromagnet and then back out onto the opposite side of the commutator and into commutator strip B.  The other piece of wire connected to the battery goes through a base magnet directly under the armature and is then connected to a brush which is  connected to commutator strip B. Finally when the battery is turned on the brushes transfer the current into the commutator and the armature powering it as well as the base magnet. This causes the base magnet and the electromagnet (armature) to interact with each other forming a magnetic field that pushes the armature away from the left and draws it toward the right causing rotation. When the armature rotates so does the commutator and when it rotates around 90 degrees that brushes lose contact with the commutator strips but the armature still moves because of momentum. when the commutator turns around 180 degrees the commutator strips A  and B are facing the opposite brushes which cause the armature to now create a different electric field where the armature is pushed away from the right and drawn toward the left. Their is a another break in the commutator strips and then the cycle repeats itself causing a full rotation over and over again.