Which device controls when the main motor of a tool receives power?

The device that controls when the main motor of a tool receives power is the trigger mechanism. This component provides the user with direct control over the activation of the power supply to the motor. When the trigger is pressed, it closes the circuit, allowing electricity to flow to the motor, thus starting it. Releasing the trigger interrupts the power, stopping the motor.

The trigger mechanism is essential for providing precise control over the operation of tools, enabling users to adjust their output based on the task at hand. This functionality is particularly important in situations requiring variable speed and load adjustments, allowing for better handling and safer operation of power tools.

In contrast, while a motor switch can turn the motor on or off, it does not typically provide variable control like a trigger does. The clutch serves to engage or disengage the power from the motor to the application but does not directly control the electrical flow to the motor. A power regulator is used to manage and stabilize electrical power but is not involved in directly controlling the on/off function for the motor. Thus, the trigger mechanism is the most accurate choice for controlling when the motor receives power.