System for automatically controlling lights in a room

摘要: A system for automatically controlling lighting fixtures, appliances, an alarm, or the like in a room enclosure has pair of sensors installed association with each entryway leading into room. The are triggered when person passes through and send signal to logic circuit which is mounted operative sensors. distinguishes between entry exit persons from on basis that door one two first case entry, other exit. signals signalling counted stored counting register separately second register. status storing number entries continuously compared comparator exits. An output generated by as result this comparison controls switching switches fixture, electric appliance off.