Abstract: A magnetic resistance trainer includes an electrically conductive disk configured to rotate in response to power provided by a user of the trainer. The trainer further includes a magnet creating a magnetic field. The magnet is configured to be positioned proximate the disk such that the magnetic field induces eddy currents in the disk when the disk is rotating. Also, the trainer includes a sensor system configured to detect the change in the magnetic field caused by the eddy currents induced within the disk. The trainer additionally includes a processor configured to receive input from the sensor system reflecting the detected change in the magnetic field. The processor determines the power provided by a user of the trainer based on the input from the sensor system.

Abstract: A 90.degree. gate opener (20) includes a screw (22), and a nut (30) which travels along screw (22) as the screw (22) is turned by a motor (46). One end of a main arm 32 is pivotally connected to nut (30) so that it also travels along screw (22). Screw (22) is dispositioned a predetermined distance (D) behind a pivot (38) which slidably receives main arm (32). As screw (22) is turned, main arm (32) rotates approximately 90.degree. about pivot (38), and in so doing also slides through pivot (38). As a result of the increased mechanical advantage of the gate opener, a motor of smaller horsepower rating may be utilized. Gate opener (20) may be used in either horizontal or vertical applications.