Abstract: A lift assembly includes a first platform provided with a top surface, a pair of opposed sides, and wheels and brackets connected to one of the sides for rotating the assembly. A plurality of rectilinear support shafts have opposed end portions conjoined to the platform and extending upwardly therefrom, and are spaced at opposed corners of the platform. Inverted U-shape guide rails are telescopically engageable along a length of the support shafts and have a pair of rectilinear regions slidably positionable about the support shafts. A second platform is provided with top and bottom surfaces, and apertures formed at opposed corners thereof that are vertically registered with the support shafts. A lifting mechanism is included for vertically biasing the second platform and the guide rails along the support shafts. The lifting mechanism is connected to the top surface of the first platform and the bottom surface of the second platform.

Abstract: The present invention relates to a circuit for driving a solid state optical emitter device such as a laser diode, and in particular a circuit which limits the maximum current which may be drawn through the device. The circuit comprises a current supply path and a current return path to which the optical emitter may be connected, and a current limit device to limit a maximum current that may flow through one of the current paths. The current limit device has a current mirror with an input portion and an output portion, the circuit being arranged so that when a first current flows through the input portion, the second portion is predisposed to supply a second current up to a maximum which mirrors the first current. The maximum current through the paths is thereby limited in accordance with the maximum of the second current.