Abstract: A system for providing backup power for a communications system is disclosed. The backup power system of the present invention includes a device for supplying capacitively stored power and a device for monitoring a power level in the communications system. When the monitoring device detects that the power level in the telecommunications system has decreased below a predetermined level, the monitoring device directs the device for supplying capacitively stored power to deliver power to the communications system such that no interruption in power is experienced by the system.

Abstract: The present invention provides a telephone network apparatus for performing speech recognition services in a telephone system in substantially real time. The apparatus uses a telephone channel signal to determine the echo delay of a telephone channel and then uses this delay to configure an echo cancellation filter for use in performing speech recognition. Use of echo delay in configuring the filter allows the echo cancellation function to be done using much less computational time than would be needed without its use, thereby granting a speech recognition unit greater access to a resident microprocessor to perform its function in substantially real time.

Abstract: A call screening service and system are disclosed for a telephone switching network. The call screening service provides a service subscriber with a number of call screening features that are subscriber setable via an automated call screening configuration subsystem internal to the telephone switching network. In particular, the call screening service allows the subscriber to set multiple call screening service activation schedules as well as to set both call screening activation and deactivation timers for immediately activating and deactivating the call screening service, respectively. An important aspect of the present invention allows the subscriber to deactivate the call screening service for a time and at the expiration of this time, the call screening service automatically reverts to using any schedules the subscriber has set for activating the call screening service.

Abstract: The gas sample identification apparatus transmits at least one beam of light of predefined frequency band through a gas sample present in a gas sampling chamber. The presence and concentration of various agents in the gas sample are determined by a linear variable filter that selectively passes the light beam transmitted through the gas sample chamber to an array of detectors. The detectors are positioned to receive only a narrow passband component of the light beam. The output signals from the array of detectors is processed by a multivariate statistical processor to accurately identify both the presence and concentration of one or more agents contained in the gas sample.

Abstract: The disclosed gas analyzer (10) provides two separate folded optical paths (16 and 18) from a single source (12) to a single detector array (14) via a polychromatic filter (26). One optical path (16) passes through a sample gas chamber (24) containing a gas to be analyzed and the other path (18) passes through a reference chamber (30) containing a reference gas. On each optical path (16 or 18), radiation from the source (12) is collected by upstream optics (22 or 28) to form a converging beam (16b, c or 18b, c), thereby reducing or eliminating the need for collection optics at the detector array (14).

Abstract: The source (12) has a heater element (122) sandwiched between elongate emitter plates (124 and 126). In operation, the source (12) is operated at temperatures in excess of 900.degree. C. and, preferably, at least about 1200.degree. C. to provide radiation in the 7-10 micrometer wavelength range. In one embodiment, the source (12) is used in conjunction with an elongate detector array (14) in a gas analyzer (10) for analyzing respiratory and anesthetic gases. Spherical mirrors (36a, 36b) and flat mirrors (38a, 38b) are employed to image the source (12) on the detector array (14). A linear variable filter (26) allows for analysis of the radiation at multiple wavelengths using detector array (14).