Abstract: An electronic learning/teaching device operates with and without a printed sheet element having an arrangement of selectable content by means of a user responsive sensor array beneath a surface configured to receive the element. The sensor array is formed by cross-points of two sets of crossing conductive lines, one set being driven sequentially with a radio frequency square wave and the other set being sampled sequentially though a high impedance amplifier connection with an asynchronous detection circuit. Where more than one cross-point location is user activated, algorithms are used to identify one cross-point sensor location as the user activated selection.

Abstract: An electronic learning/teaching device operates with and without a printed sheet element having an arrangement of selectable content by means of a user responsive sensor array beneath a surface configured to receive the element. The sensor array is formed by cross-points of two sets of crossing conductive lines, one set being driven sequentially with a radio frequency square wave and the other set being sampled sequentially though a high impedance amplifier connection with an asynchronous detection circuit. Where more than one cross-point location is user activated, algorithms are used to identify one cross-point sensor location as the user activated selection.

Abstract: A rolling toy having a tubular assembly with a helical ridge that guides movement of a ball within the tubular assembly when the toy is rolled.

Abstract: A toy power tool is shown having a tool-holding housing and a handle housing rotatably connected at interfacing surfaces inclined to the central axes of both housings. Relative rotation of the housing about a transformation axis perpendicular to the inclined interfacing surfaces transforms the tool from one desired configuration to another. A 180.degree. rotation of the tool-holding housing relative to the handle housing transforms the tool between a straight configuration with the central axes of the housings being aligned, and a L-shaped configuration with the central axes of the housings being at right-angles. Detents between the interfacing surfaces position the housings at the desired configurations, and double as switches that are connected to a sound producing circuit on a printed circuit board mounted parallel to the interfacing surfaces. An internal gear mechanism converts linear input motion to the relative rotary motion of the housings.