An intrusion alarm system with an automatic exit control and a misset indicator which informs that someone has trespassed by opening a door during the resident's absence. This system comprises a sequential circuit which is enabled by mode selection by the resident at his/her going out and which stores...http://www.google.com/patents/US4683460?utm_source=gb-gplus-sharePatent US4683460 - Intrusion alarm system with automatic exit control and misset indicator
