Patent ID: 7403131

Claim:
A power tool movement monitor system, comprising: a first accelerometer having an output and operatively configured to sense movement along a first axis of a power tool; a first high pass filter operatively connected to the output of the first accelerometer, the first high pass filter having an output and a cutoff frequency corresponding to a predetermined acceleration limit capable of being output by the first accelerometer; a first low pass filter operatively connected to the output of the first accelerometer, the first low pass filter having an output and a cutoff frequency corresponding to another predetermined acceleration limit capable of being output by the first accelerometer, wherein the logic circuit is operatively configured to generate the warning signal when the first low pass filter outputs a signal having a frequency equal to or less than the cutoff frequency of the first low pass filter for a predefined period; a logic circuit operatively configured to generate a warning signal when the first high pass filter outputs a signal having a frequency equaling or exceeding the cutoff frequency of the first high pass filter; a voltage integrator operatively connected between the first low pass filter and the logic circuit, and a voltage comparator operatively connected between the voltage integrator and the logic circuit, the voltage comparator having a bias voltage corresponding to a voltage limit derived from the predetermined acceleration limit over the predefined period.