Electric Motors

Electric Circuits zAn electric circuit is an electrical path that begins at a power source and ends up back at the power source. zThe component that is being powered by the source is called the load.

zIf the circuit isnt complete, electrons will stop flowing, which will turn off the electricity.

Direct Current (DC) zIn a DC circuit, electrons flow in one direction from the negative terminal to the positive terminal.

Alternating Current (AC) zThe electrons that flow in an AC circuit alternate. z(In other words they go back and forth)

Conductors & Insulators zConductor - A material whose atoms easily give up their outer electrons, letting an electrical current flow easily through the material Insulator - A material whose atoms hold their outer electrons tightly, resisting the flow of electrical current through the material

Electricity and Magnetism zElectricity flowing through a wire creates a magnetic field around the wire.

Electricity and Magnetism zA coil of wire that has an electric current passed through it becomes an electromagnet. By having more coils (wraps) you increase the magnetic field.

What do we know about magnets? zOpposite poles attract and like poles repel. zInside an electric motor these attracting and repelling forces create rotary motion.

Motors in your kitchen… zThe fan over the stove and in the microwave oven zThe disposal under the sink zThe blender zThe can opener zThe refrigerator - Two or three in fact: one for the compressor, one for the fan inside the refrigerator, as well as one in the icemaker zThe mixer zThe tape player in the answering machine zProbably even the clock on the oven

Motors in your basement or garage … zThe washer zThe dryer zThe electric screwdriver zThe vacuum cleaner (Dustbuster or Shop Vac) zThe electric saw zThe electric drill zThe furnace blower

Motors in your bathroom… zThe fan zThe electric toothbrush zThe hair dryer zThe electric razor

Motors in your car…. zPower windows (a motor in each window) zPower seats (up to seven motors per seat) zFans for the heater and the radiator zWindshield wipers zThe starter motor zElectric radio antennas

Other places too! zSeveral in the VCR and DVD player zSeveral in a CD player or tape deck zMany in a computer (each disk drive has two or three, plus there's a fan or two) zMost toys that move have at least one motor (including Tickle-me-Elmo for its vibrations) zElectric clocks zThe garage door opener zAquarium pumps

HOMEWORK zArmed with your new knowledge of electrical motors and the experience of building one, you are going to use your motor to teach someone else how it works. Your lesson can be given to any adult and must be completed _________ ___________. Your student needs to fill out the brief description of your lesson on the sheet provided.