1. The Direct Current (DC) Electric Motor
What you need to know:
Electromagnetism
main parts of the motor
Flow of electricity through the motor
interaction of opposing magnetic fields

2. Starting Motor Fundamentals
An automobile uses many DC motors in various systems. The main application of a DC motor is the engines starter motor.
What the starter motor does:
Converts electrical energy from the battery to mechanical energy to crank the engine
Produces a turning force through the interaction of magnetic fields inside the motor

3. Magnetic Field Action Made up of invisible lines of force
Since like charges (fields) repel each other and unlike charges (fields) attract each other, magnetic fields can produce motion

4. Magnetic Field Action

5. Simple Electric Motor
If a current-carrying winding is placed inside a magnetic field, the winding rotates away from the pole shoes

6. Commutator and Brushes
Keep a motor turning by controlling the current through the windings
Together, they serve as a sliding contact between battery power and the windings

7. Commutator and Brushes
Commutator reverses the electrical connection when the loop rotates around

8. Increasing Motor Power
Several loops of wire and a commutator with many segments are used to increase motor power
As the motor spins, many windings contribute to the motion

9. Armature Supports the windings
Iron core increases the strength of each winding’s magnetic field

10. Field Windings
Stationary insulated wire wrapped in a circular shape around iron pole shoes
When current flows, a magnetic field builds
This field acts against the armature’s field, producing motion

11. Armature and Field Windings

12. Know this diagram and be able to label these parts
This is a cutaway view of a starter motor.

13. The Starter Motor Circuit
A short video on the automobiles starter motor circuit.

14. The DC Motor Principle
A Short video explaining the interaction of magnetic fields between the armature and field coils.

15. What to Know for the Exam
For the exam you will need to know:
1. basic components: armature, pole shoes/field coils, commutator, brushes, solenoid
2. Be able to explain the basic dc motor principle….how magnetism is formed, and how opposing magnetic poles create rotation in the motor.