Abstract: A movable barrier operator system includes a barrier-motor electrical driver, a first input device for receiving operating commands, a second input device for developing system status and a controller for storing a record of all input commands received and a record of all events occurring to the movable barrier and for enabling operation of the electrical driver in response to an input command. The first input device may be a DTMF receiver or a telephone entry system. Events stored include barrier obstructions and barrier operator failures. The controller, responsive to a stored event, enable the telephone entry system to contact a service provider. For facilities with multiple barriers and a DTMF receiver at each operator, a special circuit normalizes the amplitude of a transient analog tone burst (such as from a DTMF transmission) without any transient level overshoot.

Abstract: This system is for use by a visitor to a facility that has multiple occupants, public-subscriber or other phone service, and an individual phone outlet at each occupant's part of the facility. A microphone and speaker are provided so that a visitor seeking access can speak with an occupant. A communication circuit carries signals between (1) the mike and speaker and (2) the phone service--to enable the conversation through an individual phone outlet. Manual controls, preferably including a standard phone keypad, are positioned for use by the visitor. An electronic memory holds directory information, particularly including occupant names and corresponding dial-up codes. An LCD, behind a protective window, shows the visitor the directory data. Names and other directory data can be fed into the memory remotely, preferably through either: ordinary phone connections using standard DTMF signals--with automated confirmation of input data by a voice-synthesis chip--or a modem.

Abstract: A liquid-crystal display preferably eighteen lines of forty characters each, is mounted in a case. The temperature of the display medium is held within operating limits for the display--notwithstanding ambient temperature and humidity variations over generally normal ranges for at least the temperate zones, and even if the display unit receives direct sunlight. The unit works outdoors, at temperatures to at least 46.degree. C. (115.degree. F.) as well as in buildings with no temperature control. This is accomplished by use of a shading hood, and a window (preferably unperforated polycarbonate, curved, upward-and-outward-concave, and cylindrical-segment) that reflects to a viewer only light from the hood underside. No ventilating fan, plenum or other ventilating opening is needed. A circuit-board-mounted temperature sensor controls the contrast-adjusting voltage of the display--using data in a digital-memory "look up" table. A heater is preferably provided, also temperature-controlled.

Abstract: A liquid-crystal display, preferably twenty-five lines of eighty characters each, is mounted in a case. The temperature of the display medium is maintained within operating limits for the display--notwithstanding ambient temperature and humidity variations over generally normal ranges for at least the temperate zones, and even if the display unit is placed to receive direct sunlight. The unit works outdoors as well as in buildings that lack temperature control. This is accomplished preferably by circulating air from outside the case through a space between the display face and an unperforated protective polycarbonate window. Intake and exhaust plena are long and narrow enough to deter manual access to the display and thus van dalism; however, the plena are straight and sufficiently free of obstructions that the fan can be a very small, low-power, quiet unit. A temperature sensor controls the fan, and also the contrast-adjusting voltage of the display --based on data in a digital-memory "look up" table.

Abstract: A liquid-crystal display, preferably twenty-five lines of eighty characters each, is mounted in a case. The temperature of the display medium is maintained within operating limits for the display--notwithstanding ambient temperature and humidity variations over generally normal ranges for at least the temperate zones, and even if the display unit is placed to receive direct sunlight. The unit works outdoors as well as in buildings that lack temperature control. This is accomplished preferably by circulating air from outside the case through a space between the display face and an unperforated protective polycarbonate window. Intake and exhaust plena are long and narrow enough to deter access to the display and thus vandalism; however, the plena are straight and sufficiently free of obstructions that the fan can be a very small, low-power, quiet unit. A temperature sensor controls the fan, and also the contrast-adjusting voltage of the display--based on data in a digital-memory "look up" table.