Electromagnetic Devices

Galvanometer

• A device that uses a solenoid to measure small amounts of current

How Galvanometers work

• Solenoid creates magnetic field when current goes through

• That magnetic field tries to line up with permanent magnet’s field

• Moves pointer in the process

• More current, more pointer moves

Motors

Electric motor is a device that changes electrical energy into mechanical energy that is used to do work.

Uses an electromagnet to turn an axle or rotor

Electric motor

http://spot.pcc.edu/~mfarrell/EET272/electric%20motor.gif

What kinds of devices use motors?

You are going to create this motor

How does the motor work?

• Coil has insulated side of wire and uninsulated side

• Current flows through wire = electromagnet• Coil turns to try to line up with magnet field• When coil turns, contact is broken (hits

insulated side of wire)• Momentum of coil will continue to move the

coil however until it hits the uninsulated part again – process repeats