MULTIFUNCTION DOOR INTERCOMMUNICATION SYSTEM Russian patent published in 2002 - IPC

FIELD: utility equipment for tenement houses and industrial premises; audio door intercommunication systems. SUBSTANCE: proposed device can perform additional functions, that is, it may function as emergency telephone set in apartments where telephone set is lacking or damaged and as control panel; as talk- back equipment within given porch; it may function in general notification mode, to control lighting system and automatically turn on porch lights when a lodger leaves his apartment; as burglar alarm incorporating provision for recording alarm conditions concerning persons leaving the porch including at night in absence of light; as fire alarm; as gas control device for apartment. EFFECT: enhanced reliability, noise immunity, and comfort. 6 cl, 1 dwg