A starter is used in DC motors primarily to limit the initial current surge when the motor is first energized. DC motors can draw a very high current when they are starting up due to the low initial resistance of their windings. This surge can potentially damage the motor windings or cause excessive wear on the mechanical components. The starter typically includes components like resistors or electronic devices that gradually apply voltage to the motor, allowing it to start smoothly and without overloading the electrical system.
The purpose of using a starter in DC motors is to protect the motor from damage and ensure reliable operation. By controlling the current during startup, the starter prevents overheating of the motor windings and minimizes stress on the mechanical components. It also prolongs the lifespan of the motor by ensuring it starts smoothly and operates within safe current limits.
DC motors are self-starting because of their inherent design and the way the commutator and brushes interact with the magnetic field. When voltage is applied to a DC motor, the commutator and brushes automatically create the necessary conditions for the motor to begin rotating. This self-starting capability simplifies the operation of DC motors, making them straightforward to control and use in various applications without needing additional starting mechanisms.
Starters are used in induction motors to control the starting current and torque during motor startup. Induction motors can draw a large amount of current when they are first switched on, which can cause voltage drops in the electrical supply system and mechanical stress on the motor itself. Starters for induction motors typically include devices like reduced-voltage starters or soft starters, which gradually ramp up the voltage or control the frequency of the motor’s power supply to limit the inrush current and ensure smooth starting. This helps protect the motor windings and mechanical components, extends motor lifespan, and improves overall operational efficiency.