DC motors are used where high starting torque and wide speed range control is required.

DC motors have the unique advantage of being able to provide high starting torque, making them suitable for applications where a heavy load needs to be started. This is because DC motors can produce high torque at zero speed, allowing them to overcome the inertia of the load and start it quickly.

Additionally, DC motors have a wide speed range control, meaning that their speed can be easily adjusted over a wide range of values. This is achieved by varying the voltage or current supplied to the motor, which in turn affects the speed of the motor. This wide speed range control is important in applications where precise speed control is required, such as in industrial machinery or robotics.

DC motors are commonly used in various applications where high starting torque and wide speed range control are required. Some examples include:

1. Electric vehicles: DC motors are used in electric vehicles to provide the necessary torque for acceleration and hill climbing. The wide speed range control allows for efficient operation at different speeds.

2. Conveyor systems: DC motors are used in conveyor systems to start and stop the movement of heavy loads. The high starting torque ensures that the load can be moved from a stationary position, while the speed range control allows for precise control of the conveyor speed.

3. Machine tools: DC motors are used in machine tools such as lathes and milling machines. The high starting torque allows for quick and accurate cutting, while the speed range control allows for different cutting speeds depending on the material being machined.

4. Robotics: DC motors are used in robotic systems for precise control of movement. The high starting torque allows for quick and accurate positioning, while the wide speed range control allows for precise control of the robot's speed and motion.

In conclusion, DC motors are the preferred choice where high starting torque and wide speed range control are required. Their ability to provide high torque at zero speed and their wide speed range control make them suitable for a wide range of applications in various industries.