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 ors.htm ors.htm motor.htm