How the Electric Motor Works

The Motor Effect

• Concept: When a current-carrying wire is placed in a magnetic field, it experiences a force.
• Direction of force: Depends on current direction and magnetic field direction.
  • Use Fleming's Left Hand Rule to determine direction.

Wire in Magnetic Field

• Current Direction: Current coming out of the page towards us; magnetic field to the right.
• Force Direction: Wire experiences an upward force.
• Opposite Current Direction: Force experienced is downward.

Coil Formation and Rotation

• Coil Setup: Two wires connected at the far end forming a coil.
• Current Path: From positive terminal (right) through coil to negative terminal (left).
• Force on Coil: Left side has upward force, right side has downward force.
• Initial Rotation: Coil spins clockwise.

180 Degrees Rotation and Force Reversal

• Current Reversal: Current direction reverses after 180-degree rotation.
• Force Reversal: Left side experiences downward force, right side experiences upward force.
• Result: Coil flips back and forth; doesn't complete 360-degree rotation.

Split Ring Commutator

• Purpose: Changes direction of current every half turn.
• Function: Swaps positive and negative connections every half turn.
• Result: Coil rotates consistently in one direction.

Practical Application

• Current Flow Illustration:
  • Positive terminal to commutator.
  • Through coil.
  • Out negative terminal.
  • Ensures clockwise forces and rotation.
• Real Life Usage: Found in fans, vehicles, hard drives.

Increasing Motor Power

• Methods:
  • Increase current through wire.
  • Add more turns to the coil.
  • Increase magnetic flux density using more powerful magnets.

Conclusion

• Summary: Explanation of how electric motors work and how consistent rotation is achieved.
• Applications: Everyday devices rely on these principles.
• Video Wrap-Up: Hopes for usefulness and a sign-off.