Abstract: A lighting device and control means therefor is disclosed. The lighting device consists of a plurality of White LEDs (WLEDs) provided in separate chains all connected parallel. A small number of WLEDs is connected in series in each chain, and a number of such chains are wired together in parallel between a pair of voltage lines from which current is drawn. Current measurement and adjusting means is provided firstly between a high voltage line and all the parallely connected chains, and secondly in each chain. Each current measurement and adjusting means is controlled ideally by a microprocessor which monitors both the total current drawn by all the chains together and also the individual currents flowing in each chain. WLEDs have a tendency to fail when subjected to sudden current increases, and also when operating at extreme temperatures as temperature affects the operating characteristics of diodes in general.

Abstract: A fibre optic bundle end is produced by placing the end in a ferrule (6) and the bundle (14) and ferrule (6) are supported in a furnace (22) for rotation about the ferrule axis. The ferrule (6) and the fibres (14) therein are heated and while still in the furnace (22) are radially compressed by compression members (2,4) so that the fibres become lightly packed, after which the protruding fibre ends are cut off and the cut surface (16) is polished. The compression is achieved by rotating the ferrule (6) and fibres (14) back and forth about the bundle axis while the compression members which are bars passed through the furnace (22) move together radially of the ferrule (6), the said members being mounted for reciprocation so as to allow the ferrule (6) to roll thereon as it rotates.