Abstract: A linear bearing assembly having a load compensating ball bearing array whose rolling friction increases when a sufficiently large load is applied thereto. The design of the ball bearing array permits the assembly to achieve desired torque, efficiency, end play, and static load characteristics with a high tolerance to manufacturing variations in size, surface condition, and other ball bearing characteristics. In one preferred embodiment, the assembly has an initial rolling friction until the force applied to the ball bearings exceeds a transition load, and then has an increased rolling friction after application of the transition load to the ball bearings. This step-wise increase in rolling friction is achieved by packing large, compressible ball bearings with smaller ball bearings in the race of the linear bearing assembly. When a low initial load is applied to the bearings, the large bearings bear the entire load.

Abstract: A warning device (10) is provided for use by electrical technicians or the like to indicate the presence of an electrical shock hazard. The warning device is adapted to be worn on the wrists or the like and includes a filtered detection circuit (32,34) for sensing a target signal such as an ac noise signal emitted from an electrical source. When the target signal magnitude exceeds a selected threshold (40), such as when the wearer moves into close proximity with the signal source, the warning device (10) activates an alarm (42,44) to indicate the presence of a shock hazard.