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Motorin': Whats Your Price for Flight

The trade-offs of electric motors Evan Widloski and Will Hime

The Era of Electricity Electricity has changed the world drastically in the past 150 years, and one of the many ways it has is the introduction of Electric motors. Motors play a huge role in our lives. From taking us where we need to go, to grinding up coffee beans in the morning, there are many kinds of motors and they all serve different purposes. But what differentiates motors from other motors? And how do these motors function?

What will be covered • brief history of the electric motor • explanation of electromagnetism • construction of a motor • comparison of several types of motors and their advantages • conclusion

History of Electric Motors • First electric motor created by Faraday in early 1800's • Consisted of wire hanging down into a cup of Mercury with a magnet in the middle • When a current passed through the magnet, the wire began to revolve around it. Farraday's First Motor http://www.sparkmuseum.com/MOTORS.HTM

History of the Electric Motor • It wasn't until about ten years later that motors took on a more practical format. • Rev. William Ritchie began experimenting on a motor with coils. • This, in function, is similar to modern motors

http://www.sparkmuseum.com/MOTORS.HTM

Electro-Magnets • Electro-Magnets consist of a electrified metal coil wrapped around a semi-magnetic metal. • The electrified wire creates a magnetic field that amplifies the field of the object, thus creating a powerful magnet. • However, this magnet can be powered off if the need arise, which is more convenient than a permanent magnet. • The Magnetic field of an electro-magnet is not omnidirectional like that of a rare earth magnet, it is in one direction and also rotational. http://electronics.howstuffworks.com/motor1.htm

Anatomy of an Electric Motor • motors consist of a series of electromagnetic coils which are fired in a sequence to drive a central shaft, or rotor • the rotor is surrounded by magnets. this provides an opposing force for the rotor to “push off of” - stator • motors need a way for the coils to push and pull at different times, not just push constantly. this is accomplished by a

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animation

Types of Electric Motors Brushed Motors • use small brushes to switch current back and forth Brushless Motors • uses sensors and electronics to switch current back and forth

Brushed Motors Brushless Motors • Brushless Motors use a cylinder of magnets surrounded by a ring of coils. • The coils are charged, which spins the magnet. • This is basically the inverse of a brushed motor • It also cause little to no friction as no contact is made between surfaces. • This setup is superior in high-speed applications or at highly variable speeds

Brushless Motors • Brushless Motors use a cylinder of magnets surrounded by a ring of coils. • It also cause little to no friction as no commutator is required • This setup is superior in high-speed applications or at highly variable speeds • Requires an electronic control, which can easily double its price

Brushless Motors (cont.) • Brushless Motors use a cylinder of magnets surrounded by a ring of coils. • The coils are charged, which spins the magnet. • This is basically the inverse of a brushed motor • It also cause little to no friction as no contact is made between surfaces. • This setup is superior in high-speed applications or at highly variable speeds

Conclusion Pros Very Good for high-torque situations.

Brushed

Powerful Tough and reliable

Cons not very fast

heavy/bulky could possibly have "too much" torque and break parts or strip gears

Sensitive to excessive vibration

Brushless

High-Speed waterproof versatile

Expensive (requires separate speed control)

will stall if to much torque is put on it "Smart"

Works Cited • http://www.sparkmuseum.com/MOTORS.HTM • http://electronics.howstuffworks.com/motor1.htm • http://www.animations.physics.unsw.edu.au/jw/electricmotors.html • http://www.walter-fendt.de/ph14e/electricmotor.htm