Constant current supply equipment for large number of lighting units - involves arranging units in groups supplied in series

摘要

The method is used for lighting units which are spread over a large area e.g. street lighting, airport, and runway lighting. The lighting units are arranged so that the neighbouring units to any one unit are supplied from separate circuits. Thus the overall lighting is not reduced very much by loss of one circuit. To avoid loss of lighting with loss of mains supply, each group circuit is fed by a single phase inverter from a d.c. battery source and mains rectifier. The lighting units in one group circuit are all connected in series, and the inverter output current is regulated. Thus all lighting units may give an equal amount of light if the output current of all the inverters is set to the same value.