Improvements in or relating to onboard equipment for aircraft and the like

• Main Authors: DAN LEACH, PETER DAVID STOKES
• Format: Patent
• Language: English
• Published: 20.02.2008
• Subjects: ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING ORSUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES INGENERAL; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONTROL OR REGULATING SYSTEMS IN GENERAL; CONTROLLING; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; GENERATION; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS ORELEMENTS; PERFORMING OPERATIONS; PHYSICS; REGULATING; SIGNALLING; SYSTEMS FOR STORING ELECTRIC ENERGY; TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILARSIGNALS; TRANSPORTING; VEHICLES IN GENERAL

A system e.g. an emergency lighting system for an aircraft, comprises networked devices e.g. light units (501) employing LEDs as the light source, wherein one or more units (501) is operable to carry out a self test cheek to determine the number of LEDs that are working and provide a signal to a master controller (502) to indicate if the unit (501) is operational. The check is performed by measuring and comparing a current representative of the number of operational LEDs with a current for a permitted minimum, optionally using a sub millisecond pulse. The system may employ a multi-code generator and may support wireless communication between the devices and the master controller (502). The light units (501) may comprise a flat panel diffuser, and may perform further self test checks including: a battery life check; a circuit integrity check. An IRDA interface may be provided on one or more units (501). The devices may cycle between an operable (awake) and an inoperable (asleep) condition.