Digital communication system which can be utilized as a security system for apartment houses or the like

摘要: A signal transmitter located in each occupant''s apartment of an house, condominium, or the like, is connected to usual commercial 115 VAC, 60 Hz power line common all apartments including manager''s quarters. receiver quarters also line. Each designed superimpose a having predetermined frequency on The initiated when triggered by commercially available device capable detecting invasion apartment''s security. length for designate particular which source signal. programmed detect and provide corresponding output pulse every negative-going transition voltage so long as remains superimposed devices count pulses visually display number being threatened. Audible warning can be utilized alert manager. system used monitor reading operation numerous other types installations service station gas pumps, industrial controls, remote monitoring stations, hospital, motel school signaling systems.