A control system for a power tool is disclosed. The control system comprises: a sensing unit configured to sense an operating characteristic of the power tool; a first control unit configured to determine whether the operating characteristic is within a safe operational range, and to output a first control signal at least partially based on the determination; a second control unit configured to determine whether the operating characteristic is within a safe operational range independently of the first control unit, and to output a second control signal at least partially based on the determination; and an output unit configured to receive the first and second control signals and to activate the power tool when the first and second control signals are received.