Abstract: Position indicating device for producing an indication of the position of a displaceable structure, the device including:a plurality of sensing elements extending along a defined path such that each element is associated with a respective location along the defined path, each element being operative to respond to the presence of a position representing member when the member extends from a starting point to the respective location associated with that element, the elements being coupled into respective pairs of elements, with each pair of elements having an output producing a signal only when a single element of its respective pair is responding to the presence of the member; a plurality of signal producing members each operative for producing a signal representing a predetermined logic state in response to a predetermined input signal; and circuit components operatively connecting the outputs to the signal producing members for causing a signal at each output to produce a predetermined input signal at a corr

Abstract: A digital rod position indicator having discrete coils spaced along the travel path of an elongated magnetically permeable member stores in digital form compensation signals for automatically adjusting the location relative to the coils at which the digital output signal representative of the position of the end of the elongate member transitions from one code to the next. The appropriate compensation signal is addressed using the digital output signal and a correction factor which takes into account the direction of movement including reversals.

Abstract: A voice-controlled elevator security system. Access to an elevator system servicing a plurality of landings of a structure is controlled by comparing a voice signal of a potential user of the elevator system with stored voice signals of all authorized users. The comparison is accomplished by first digitizing the potential user's voice signal and comparing it, on a bit-by-bit basis, with a digital representation of the voice signals of all authorized users. If the comparison satisfies an established criterion, the potential user is determined to be an authorized user. Once this determination has been made, the authorized user can initiate car call signals for those landings to which the authorized user is permitted access. An authorized user can also temporarily modify the previous digital representation of the voice signal when the authorized user is suffering from laryngeal indisposition.

Abstract: An inadvertent approach to criticality in a nuclear fueled electric power generating unit is detected and an alarm is generated through on-line monitoring of the neutron flux. The difficulties of accurately measuring the low levels of neutron flux in a subcritical reactor are overcome by the use of a microcomputer which continuously generates average flux count rate signals for incremental time periods from thousands of samples taken during each such period and which serially stores the average flux count rate signals for a preselected time interval. At the end of each incremental time period, the microcomputer compares the latest average flux count rate signal with the oldest, and preferably each of the intervening stored values, and if it exceeds any of them by at least a preselected multiplication factor, an alarm is generated.

Abstract: A voice-controlled elevator security system. Access to an elevator system servicing a plurality of landings of a structure is controlled by comparing a voice signal of a potential user of the elevator system with stored voice signals of all authorized users. The comparison is accomplished by first digitizing the potential user's voice signal and comparing it, on a bit-by-bit basis, with a digital representation of the voice signals of all authorized users. Various criteria can be established for determining the number of binary bits that must agree to conclude that the potential user is an authorized user. Once this determination has been made, the authorized user can initiate car call signals for those landings to which the authorized user is permitted access.

Abstract: In a document scanning scheme where data is preceded on the document by a preprinted document scan mark, circuitry is employed to utilize multiple line scans of the scan mark by a line scan camera to verify the presence of a scan mark and avoid erroneous response to random marks on the document.

Abstract: The light levels reflected from a predetermined blank portion of an optically scanned document are monitored. The presence of dirt or smudges in the optical path which could adversely affect the validity of the information read from the document.

Abstract: Shift registers are employed in a video line delay circuit coupling the output of an analog to digital converter to a digital processor in a line scan camera document reading system to permit a prescribed delay in the transmission of data to avoid loss of data appearing on a document prior to the document scan mark which is used for enabling the digital processor.

Abstract: A monitoring circuit for digital circuits is disclosed. The monitor is primarily applicable to digital circuits which operate in a cyclic mode with the digital patterns generated during each cycle being repeated in a predictable manner. A predetermined number of expected bit patterns are stored in a programmable memory. The stored bit patterns correspond on a bit-by-bit basis to the bit patterns generated by the circuit being monitored when this circuit is operating normally. In the self-scan mode each pattern generated by the circuit being monitored is compared to each of the patterns stored in the memory in a sequential manner. Each time a pattern generated by the circuit being monitored is found to identically correspond to a pattern stored in the memory a valid pattern pulse is generated which steps a down counter one count.

Abstract: A monitor for checking a plurality of multi-bit digital patterns generated by a system being monitored to determine that each pattern is valid, that each of the patterns appear in the right sequence and that the total number of valid patterns detected during the testing cycle is as expected is disclosed. Additionally, the bit patterns are monitored to detect unexpected transitions. The results of these tests are then combined to form a composite malfunction signal indicative of the operational status of the system being monitored.