Electric Motors

How they work and where they are used.

By: Prajesh Prajapati

Inside a Electric Motor

Armature or Rotor Commutator Brushes Axle Field Magnet A DC power source

Basics of a Motor

An electromagnet is the key part to a motor An electromagnet is a created by wrapping a

wire around a metal rod with many loops, and then connecting it to a battery

Then it will become a magnet

with a north and south pole

Basics of a Motor Ctd.

In this case the nail would only turn half way and stop

Motor needs to be constantly moving Moment it stops the poles need to be reversed Change direction of electron flow in wire Swap positive and negative connection to

battery Then motor will spin freely

Applying it to a Motor

The nail is replaced with the armature It is a electromagnet made by wrapping wire

around two or more poles of a metal core Reversing the polarity is accomplished by the

commutator and brushes Contacts of the commutator are fixed to the axle Brushes make contact with communator

Diagrams

Putting it together

Slight Differences

Electric motor usually has three poles Prevents motor from getting stuck In a two pole motor, commutator shorts out the

battery when “flip” occurs No shorting in a three pole motor

Where they are used

Fans Washers Electric screwdrivers Refrigerators

References

http://www.solarnavigator.net/electric_motors.htm

http://www.howstuffworks.com/inside-motor.htm