Abstract: A compact smoke alarm assembly (10) is disclosed. The assembly (10) comprises: a smoke detection chamber (20) defined by a body (22) having a plurality of openings for allowing airflow therethrough, the body (22) having a sound inlet aperture (25); a smoke detector (30) mounted to the body for communication within the chamber (20); an electrical circuit operatively connected to the smoke detector (30), the circuit providing an electrical signal when the smoke detector (30) detects smoke in the chamber (20); and a piezoelectric disc (40) mounted external to the chamber adjacent to the sound inlet aperture, the piezo disc (40) operable in response to the electrical signal to generate sound. The smoke detection chamber (20) is sized substantially in accordance to the Helmholtz formula to cause resonance at the operating frequency of the piezo disc (40).

Abstract: A shuttered electrical connector for receiving an electrical plug, the plug having a hinged tail for lockingly engaging with the connector, is disclosed. The connector includes: a body 20 defining a socket having 22 an open mouth 24; a central shutter 30 hingedly mounted to the body 20 adjacent the open mouth 24 for rotation about a first hinge axis 32; and a pair of spaced apart side shutters 40 & 50 hingedly mounted to the body 20 adjacent the open mouth 24 for rotation about a second hinge axis 42, the second hinge axis 42 parallel to and spaced apart from the first hinge axis 32. The shutters are rotatable through approximately 90 degrees from: a closed position in which together they cover the open mouth 24 while presenting a substantially flat outer face, to an open position receiving the plug in which the central shutter is offset from the side shutters.

Abstract: A detector assembly (10) powered by mains electricity and an elongate backup battery (76) is disclosed. The assembly includes: a ceiling mountable base (10) having a body defining a downwardly opening socket (24); a detector module (20) having a battery support portion (75) for holding the battery (76) in a vertical orientation, the module (20) receivable by the socket (24); a quick connection means for mechanically and electrically connecting the module (20) to the base (10); and shutter (50) mounted to the base (10). The shutter (50) prevents operation of the quick connection means when no vertical battery (76) is installed within the module (20). The quick connection means comprises co-operable pairs of conductors. The conductor pairs transmit power from the base (10) to the module (20). The pairs of conductors each comprise a stud conductor mounted to the base (10) and a forked conductor mounted to the module (20).