Whenever a DC MOTOR starts it requires a current that is equal to 5-6 times its load current to start.Thus it is required to reduce the voltage when the motor starts.This job is done with a starter.In its simplest form, the starter of a dc motor works like a variable resistance in series with the armature circui.Its work is to reduce the starting voltage upto such a value so that the increased current does not burn the armature windings. As the rotating armature of dc motor picks up speed, the starter resistance is gradually reduced to almost zero. At full speed the motor starts running normally, i.e. the job of starter finishes here.
In other words, the starter offers resistance during starting of dc motor only,to provide large current. At full speed,the starter is electrically out of armature circuit of the motor.
In other words, the starter offers resistance during starting of dc motor only,to provide large current. At full speed,the starter is electrically out of armature circuit of the motor.
