Abstract: A protection circuit may be electrically connected to a transformer neutral of a power grid transformer. The protection circuit may include a direct current (DC) blocking component electrically connected between the transformer neutral and a ground connection, as well as a direct current switch assembly positioned in parallel with the direct current blocking component between the transformer neutral and the ground connection. The direct current switch assembly includes at least one direct current switch having a switching element that is electrically controllable between a closed position and an open position. In some examples, a conductive housing encloses one or more switching elements. The conductive housing is electrically isolated from the ground connection. In further examples, one or more direct current switches may be electrically connected in series to provide greater voltage withstand and safety due to operational redundancy.

Abstract: A sharpening tool having a handle having a variable speed switch and a support grip, a removable universal tool adapter rotatably coupled to the handle, a locking feature for locking a position of the removable universal tool adapter, and a motor for driving a tool coupled to the removable universal tool adapter.

Abstract: A knife sharpener comprises a grinding surface for grinding a blade of the knife when the blade is moved relative to the grinding surface and an observation device including a sensor element and a display element. The sensor element is configured to observe the blade and to collect data regarding the blade when the blade is moved relative to the sensor element. The display element is configured to communicate a condition of the blade to an operator of the observation device. The condition of the blade is based on the data collected by the sensor element when the blade is moved relative to the sensor element.

Abstract: A knife sharpener comprises a grinding surface for grinding a blade of the knife when the blade is moved relative to the grinding surface and an observation device including a sensor element and a display element. The sensor element is configured to observe the blade and to collect data regarding the blade when the blade is moved relative to the sensor element. The display element is configured to communicate a condition of the blade to an operator of the observation device. The condition of the blade is based on the data collected by the sensor element when the blade is moved relative to the sensor element.

Abstract: A sharpening tool having a handle having a variable speed switch and a support grip, a removable universal tool adapter rotatably coupled to the handle, a locking feature for locking a position of the removable universal tool adapter, and a motor for driving a tool coupled to the removable universal tool adapter.

Abstract: There is provided a method of dispensing telephone cards from automatic teller machines (ATM) and card constructions used therewith. Telephone time is apportioned to a number of sheetlets printed with random numbers which serve as a personal identification number (PIN). They are packaged in bricks and activated when installed in an ATM or when dispensed. The sheetlets are capable of being dispensed like currency and may contain the PIN on a removable zone.

Abstract: The present invention is a membrane method and apparatus for separating isotopic water constituents from light water. The method involves providing a supported membrane of an aromatic polyphosphazene and pressurizing the water on one side of the membrane thereby forcing the light water through the supported membrane while isotopic water constituents are retained or vice versa. The apparatus of the present invention includes an aromatic polyphosphazene placed on a porous support and means for pressurizing water through the membrane while certain isotopic water constituents are retained.

Abstract: A radioluminescent light source comprises a solid mixture of a phosphorescent substance and a tritiated polymer. The solid mixture forms a solid mass having length, width, and thickness dimensions, and is capable of self-support. In one aspect of the invention, the phosphorescent substance comprises solid phosphor particles supported or surrounded within a solid matrix by a tritium containing polymer. The tritium containing polymer comprises a polymer backbone which is essentially void of tritium.

Abstract: A radioluminescent light source comprises a solid mixture of a phosphorescent substance and a tritiated polymer. The solid mixture forms a solid mass having length, width, and thickness dimensions, and is capable of self-support. In one aspect of the invention, the phosphorescent substance comprises solid phosphor particles supported or surrounded within a solid matix by a tritium containing polymer. The tritium containing polymer comprises a polymer backbone which is essentially void of tritium.