Improvements in or relating to electrically operated warning systems.

摘要

1,177,361. Emergency supply systems. WALTER KIDDE CO. Ltd. 20 Jan., 1967 [7 Feb., 1966], No. 5342/66. Heading H2H. A warning system e.g. a fire alarm normally supplied from the mains has a stand-by battery 12 normally trickle charged but supplied from a higher current unit when the battery charge drops below a value determined by a transistor circuit, which unit may also supply normal system current. The alarm system may be divided into a number of sections 16-18 each of which has an individual alarm 26 commoned to a main alarm which may be repeated for example at a local fire station over a telephone-type circuit 27.