ELECTROMAGNETISM: HOW TO BUILD YOUR OWN ELECTRIC CAR

By Fernando Olmos

5/23/13

Lesson Outline

Day 1 Brief Presentation on electromagnetism and

electric cars Do It Yourself (DIY) activity 1 – How to build

a battery Day 2

DIY activity 2 – How to build an electric motor

Wrap-up

Goals

Understand how electromagnetism principles apply to electric cars Learn how an electric motor works Learn how a battery works

Learn the basic concepts on how to build an electric car

Learn features of electric cars

Review of Electromagnetism I

An electric current produces magnetism, and a magnet can produce an electric current

Review of Electromagnetism II

Electricity creating magnetism Each electron has an electric field When the electron moves, it also creates a

magnetic field When electrons move through a conductor

(metal or coil of wire) the conductor becomes an electromagnet.

Review of Electromagnetism III

Magnetism creating Electricity Coil of wire placed near a magnet Change the magnetic field by moving the

magnet back and forth or spinning the wire Changing magnetic field produces and

electric current in the wire

How do Electric Motors Work? I

A current turns a conductor into an electromagnet

When the electromagnet is placed near a fixed magnet, the two sets of poles repel and attract each other

This produces a force that makes the conductor rotate (spin) at high speed, which turns a shaft

How do Electric Motors Work? II

How do batteries work?

First battery: voltaic pile by Alessandro Volta in 1800

Electrons move from one metal to the other metal through a saltwater solution

Saltwater solution is called an electrolyte Contains ions in solution from the

dissolved salts Ions react with the metals making

electrons. Metal are called electrodes

Electrical potential difference (voltage); one positive, one negative

Electrons move, creating an electrical current

Electric Car Features

Runs on an electric motor 100% pollutant emission free Gets power from batteries, wind, or sun Motor is way smaller than gasoline engine Quiet to drive Limited range (~60 to 100 miles) More frequent refueling Charging time takes hours

Electric Car Features