Electric motors are machines that convert electrical energy into mechanical energy operating by using an interaction between a magnetic field and currents to then produce a force known as rotation. There are two sources of power for electric motors, direct current (DC) from batteries or alternating currents (AC) from electrical generators and power grids.
History of the motor
Electric motors first came about in the 1700s where they were simple electrostatic devices running on Ampère’s force law. This law talks about the force of attraction or repulsion between two current-carrying wires, which then generates a magnetic field. Big names like Benjamin Franklin and Michael Faraday had a part to play in the electric motor’s humble beginnings.
50 years after Faraday’s experiments, Zenobe Theophile Gramme was the person who introduced the version of an electric motor that made a commercial impact. Electric motors today are made of several components including, the bearings, rotor, stator, which may be a permanent magnet, windings and commutator. The space between the rotor and the stator is known as an air gap, which has negative effects on the motor’s performance. The motor’s power, or torque is determined by the voltage and length of wire in the stator. The longer the wire, the stronger the magnetic field, leading to a stronger motor.
Today motors are used all around us. They exist in our home appliances, such as in fans, clothes dryers and refrigerators. They are used in transport, powering trains, electric cars and other electric vehicles, such as Segways and golf carts. Electric motors can also be found in big industrial equipment such as in forklifts and hydraulics used to lift bulky loads.
STEM and motors
STEM refers to the study of Science, Technology, Engineering and Mathematics related subjects. STEM methods of teaching hope to interest students to become excited about Math and Science subjects. It uses real life situations paired with hands on and activity based learning in order to show students the theories and concepts that they need to learn. Learning about motors is very much in line with STEM ideologies, figuring out about electromagnetism at the same time applying these concepts to pick apart how simple objects around us work.
STEMmates and motors
We have recently launched our Electric Motor course as part of our school holiday program for 10-12 year olds. The course is an ideal extension to our Electromagnets workshop, allowing children to apply the knowledge gained there. Children are able to plan, build and modify simple electric motors using wires and magnets. Here they learn through asking questions and critical thinking. They employ systematic problem-solving and communication skills in order to carry out simple engineering design practices. Find out how your child can get excited about STEM subjects and learn how to build their very own electric motor. Check our Facebook and website pages for more information today.