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.

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.

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.

Abstract: An analytical rotor intended primarily for performing immunoassays comprises one or more inlet chambers for sample, wash reagents, and labelling reagents. A reaction chamber is disposed radially outwardly from the inlet chambers and connected thereto by low flow resistance flow paths. A collection chamber is located radially outwardly from the reaction chamber and connected thereto by a high flow resistance flow path. Samples are introduced to the sample inlet chamber by a transfer device, with sample volumes optionally determined by detecting when the sample inlet chamber is filled. Reagents initially introduced to the inlet chambers may be selectively transferred to the reaction chamber by low speed rotation of the rotor. The reaction chamber may then be emptied by high speed rotation of the rotor. In this way, heterogeneous immunoassays requiring sequential contact of reaction zones with sample and different reagents may be performed.

Abstract: An analytical system comprises a frame and movable carriage. An analytical rotor is mounted on the carriage and can be translated among a sample dispensing station, a fluid dispensing station, and a label detection zone. In order to perform assays, the analyzer system requires only the introduction of the analytical rotor, sample, and a volume of diluent solution. Sample within the analyzer is contained at all times within either a sample receptacle or the rotor. The method allows for the sequential addition of sample and diluent in order to perform multiple assay steps and is particularly suitable for performing heterogeneous immunoassays. The use of fluorescent label in the system allows multiple analyte detection reactions to be performed from a single sample applied to a single rotor.

Abstract: A position-sensing circuit includes an elongated electrically-conductive element divided into two elongated segments. A conductor moves along the element, maintaining electrical contact with at least one of the segments. A first capacitor is connected to the conductor and a second capacitor is connected to one of the segments. When the conductor bridges a gap between the segments, a step-wise change in the time constant of the circuit results. This step-wise change precisely and reproducibly indicates the position of the conductor as being across the gap. The circuit finds particular advantage in a three-way dimming system that permits a remote switch to provide power to a load even if a dimmer that controls the load has been set to provide minimum or no power to the load.