What is the main purpose of a deadman switch on power tools?

The main purpose of a deadman switch on power tools is to cut power when not pressed. This safety feature is designed to minimize the risk of accidents by ensuring that the tool automatically shuts off if the user loses grip or becomes incapacitated. By requiring continuous pressure to maintain operation, the deadman switch helps prevent unintentional activation, which could lead to injuries or damage if the operator is unable to control the tool. This design emphasizes safety and enhances user control over the power tool during operation.

In contrast, starting the machine automatically would not align with the functionality of a deadman switch, as this would pose a greater safety risk. Indicating a safety signal typically involves different types of alerts or lights and is not the primary role of a deadman switch. Similarly, while some tools have features to regulate speed, that is a separate function that does not relate to the purpose of ensuring safety by cutting power.