Smoke detector devices and detector circuit.

摘要

A smoke detector device comprises a housing (30) adapted to be mounted below an existing ceiling rose fitting (32) and to be clamped to an electrical flex (38) passing therethrough. The housing (30) encloses a smoke detector circuit formed on a printed circuit board (62), a battery (48) and an alarm sounder (50). The device is intended particularly for use in domestic environment, and is intended unobtrusive and inexpensive. An alternative embodiment includes a housing adapted to replace existing ceiling rose fittings; A novel photoelectric-type detector circuit, incorporating an integrated circuit and high intensity light emitting diode, is also described, which again is intended to be compact and inexpensive.