Abstract: Power supplies for pool and spa equipment are disclosed. In one embodiment, the power supply includes a buoyant housing, a peripheral float, at least one solar cell positioned on the buoyant housing for collecting sunlight and converting same to electrical energy, and a power cable for interconnecting the power supply and pool/spa equipment. In other embodiments, first and second inductive power couplings are provided for powering pool and spa equipment. The power couplings can also be installed using existing plumbing features of the pool or spa.

Abstract: It is sometimes required to track randomly moving objects with precision and high speed. This inventioin pertains to a mirro rotation assembly that provides precise, high-speed pitch and yaw tracking by rotating a low-moment-of-inertia mirror rather than rotating a heavier double gimballed mirror assembly or the camera-lens assembly itself. By pivoting the mirror on a single bearing point and controlling the mirror surface pitch and yaw by driving two mirror tie points along circumferential paths around the bearing point, a low moment of inertia is obtained. The low moment of inertia together with mirror velocity rather than position control permits higher speed tracking while maintaining the required precision. The velocity control strategy minimizes image blur resulting from unpredicted object motions.

Abstract: A system for focussing a lens on a point light source is provided that includes an opaque member disposed near the lens. The member cast a shadow having a distinguishable orientation in the image of the light source. An image processing device determines the focus condition and range to the point light source from the orientation and size of the shadow.