Abstract: A method for detection of false positive condition that an object is in contact with an implement in a power tool includes sampling an electrical signal received from the implement, identifying in-phase and a quadrature components of the sampled electrical signal, identifying a magnitude of each of the samples with reference to the in-phase component and the quadrature component for the samples, detecting an object approaching the implement with reference to the plurality of samples, identifying a signal-to-noise ratio for the samples, and identifying a false positive condition for the detected object with reference to the identified signal-to-noise ratio for the identified samples.

Abstract: Methods to detect when a human body contacts a predetermined portion of a machine are disclosed. The methods distinguish contact with a person from contact with other materials. The methods are particularly applicable in woodworking equipment such as power saws to distinguish contact between a person and the blade of the saw from contact between the blade and wet or green wood. Woodworking machines and memory devices for use in woodworking machines having safety systems designed to detect a dangerous condition between a human and a dangerous portion of the woodworking machine and to trigger some action to mitigate the dangerous condition are also disclosed.

Abstract: Methods to detect when a human body contacts a predetermined portion of a machine are disclosed. The methods distinguish contact with a person from contact with other materials. The methods are particularly applicable in woodworking equipment such as power saws to distinguish contact between a person and the blade of the saw from contact between the blade and wet or green wood. Woodworking machines and memory devices for use in woodworking machines having safety systems designed to detect a dangerous condition between a human and a dangerous portion of the woodworking machine and to trigger some action to mitigate the dangerous condition are also disclosed.

Abstract: Improved methods to detect when a human body contacts a predetermined portion of a machine are disclosed. The methods distinguish contact with a person from contact with other materials. The methods are particularly applicable in woodworking equipment such as table saws to distinguish contact between a person and the blade of the saw from contact between the blade and wet or green wood.