Starter Basics P 206

Motor Principles n DC motors interaction of magnetic fields to convert electrical energy to mechanical energy n Current is applied to field and armature n Conductor tends to move from weak magnetic field to strong magnetic field. n For armature to continue rotating, the current flow must be reversed.

Conductor Current n Conductor has magnetic flux lines around it n Opposes north and south fields which causes loop of wire to turn. Page C138

Magnet n Has north and south pole. n Magnetic lines of force move from north to south pole. Page C138

Conductor in Magnetic Field n As current travels through conductor and fields, conductor moves. PAGE C138

n Flux lines always tend to want to be straight n Fields act on each other

ROTATION OF CONDUCTOR IS IN DIRECTION OF WEAKER FIELD. PAGE C139

Electromagnetic Motor Page C139

n Made of Laminated Core n Solid Steel Shaft n Commutator n Lap and Wave Wound (P C141)

Stationary Field Windings n Iron Core & Windings concentrate magnetic field n Fields have north and south pole based on direction windings are wound around pole shoes

3 Methods of Connecting Fields n Series Wound n Maximum torque when starts n Shunt Wound n Used in smaller motors n Compound Wound n Constant speed Page C143

The power is in the size of the windings, the size of the windings, the number of turns and how its wound

PERMANENT MAGNET STARTER MOTOR n Has no field circuit n Very light weight n Usually gear reduction starter motors n Fairly fragile n Permanent magnets are stronger than typical permanent motors (Made of boron, neodymium and iron)

ANDTHATS ALL!! AND THATS ALL!!