Investigation 4.1 Electric Motors

Some questions to reivew what we know!

In class, we looked at three main parts of the dissected motor:

1) Casing

2) Shaft Component

3) Cap

​The metal casing contains the two permanent magnets of the motor.

Casing

The shaft component contains the shaft, the electromagnets and the commutator.

Shaft Component

​The cap contains the two brushes which connect to the outer wires.

Cap

The term for those flat ends of wire is brush.

The current runs in through the wires from the battery, through the brush, to the commutator.

The current passes through contact between the brush and commutator.

The commutator has three gaps.

Depending on where the commutator is in the rotation, it’s touching only two contact points (brushes), so two parts will receive the electric current and one part will not.

Two sections of current will pass through the commutator to the electromagnets and one will not at any given time!​

Only two sections of the electromagnet are turned on at one time; when turned on, these sections repel from the permanent magnets in the case, causing the shaft to rotate

As soon as the shaft rotates, the commutator is in a new position and one section will turn on while another turns off

The cycle will continue, turning the shaft over and over again.