Faraday Motor

faraday_motor.pdf

Michael Faraday’s Homopolar Motor:

Research done by Zoe, Sowmya, and Bela

  • Invented in 1821 (discovered right before electromagnetism) → Michael Faraday
  • First electrical motor to be built
  • Also known as unipolar motors
  • Simpler structure, higher rotor strength, and lower iron loss in rotations
  • Direct current (DC) and Low voltage
  • Used in modern day plating, turbines, and toys.
    • Plating: used in generators installed for electroplating process plants
      • Has evolved to have high enough voltage to operate heavy machinery despite low power outage
    • Turbines: used in high-torque wind turbines
      • Provide low cost means of converting wind to electricity due to reduced need for multidirectional gears
      • Require less maintenance than bipolar motors
    • Toys: small engines in toy cars are an example of the homopolar motor
      • Spinning wheel create force → magnet spins and creates electric field
      • Electricity is flowing in one direction to power the car (the engine specifically)
  • Can be inefficient due to counterflow of current, causing inefficiency of early homopolar motors
  • Homopolar motor is driven by Lorentz Force → this force provides a torque around the axis of rotation (parallel to magnetic field)
  • Powers motor in one direction
  • Useful for demonstrating scientific forces such as electromagnetism
  • Otherwise kind of useless due to high electrical currents, poor efficiency, and inability to get much useful power out of it
  • Magnet and compass (deviating the needle) → do the same with copper wire and AA battery → demonstrate electromagnetism

“The magnet’s magnetic field pushes up towards the battery and the current that flows from the battery travels perpendicularly from the magnetic field. This causes the creation of a force perpendicular to both the magnetic field and current. This force, known as the Lorentz force, is exerted on the copper wire (the conductor) causing it to spin” (CSUB)

Questions:

  1. What’s the difference between a homopolar generator and a homopolar motor?
  2. Were homopolar motors the beginning of cars → possible relevance between modern cars and the motor?
  3. Can homopolar motors or even just remnants of it be found in everyday inventions? (pulleys → elevators)

Vocabulary:

Electromagnetism: the physical interaction among electric charges, magnetic moments, and the electromagnetic field

Torque: a twisting force that speaks to the engine’s rotational force and measures how much of that twisting force is available when an engine exerts itself

Lorentz Force: the force exerted on a charged particle q moving with velocity v through an electric field E and magnetic field B

Formula : F = q( E + vB)

F = force

q = electric charge

E = external electric field

vB = velocity times magnetic field

Do It Yourself (DIY) Homopolar Motor:

By Vanisha Nagali

*Use the link below for step by step instructions*

HM Instructions