How to Resolve Starting Difficulties in a Brushed DC Motor?

Starting difficulties in a brushed DC motor typically refer to the motor's inability to start smoothly or insufficient starting torque after power is connected, leading to the load's inability to operate normally. Based on professional repair experience and technical literature, this mainly involves the inspection and adjustment of the motor's internal and external systems.

1. Check for internal motor faults:

Weared brushes: This is the most common cause. After prolonged use, the brushes may wear to their limit, resulting in poor contact. Replace the brushes promptly to ensure good contact with the commutator.

Commutator (armature) condition: Check the commutator surface for scratches, burns, or carbon buildup. If the surface is uneven, it should be polished or recoated with copper to restore its conductivity.

2. Verify power supply voltage:

Insufficient voltage: If the power line is too long or the mains voltage fluctuates significantly, the supply voltage may be lower than the motor's rated voltage, resulting in insufficient starting torque. It is recommended to use a regulated power supply or check the wiring connections for security.

3. Reduce Load or Use Assisted Starting Methods:

Overload: If the load on the motor suddenly increases (e.g., due to mechanical jamming), the motor may fail to start due to insufficient torque. In this case, the load should be reduced or applied in stages.

Assisted Starting Circuit: For high-power motors, consider using capacitor-assisted starting or series resistor voltage-reduction starting circuit designs to help the motor overcome static friction during starting.