What function does a drum switch primarily serve?

A drum switch primarily serves the function of motor control. It is designed to allow the user to start, stop, and reverse the direction of an electric motor. The construction of a drum switch includes a rotating drum or paddle that connects to different circuit contacts, enabling the operator to easily switch between different operational states of the motor. This functionality is especially useful in applications where precise control over the motor's actions is necessary, such as in cranes, conveyors, and industrial machinery.

When a drum switch is activated, it controls the flow of electricity to the motor, facilitating its operation in both forward and reverse directions without the need for complex wiring changes. This makes it a convenient solution for applications requiring frequent changes in motor direction or speed.