Westinghouse Electric Corporation

Michal M Feilchenfeld

Kenneth E Daggett

James A Neuner

Roger Graham Byford

Douglas A Bauman

Raymond A Lloyd

Wing C Quan

Lesley Greenberg

Charles G Geis

Charles R Tuley, Jr

Grant R Connors

Position indicating device for producing an indication of the position of a displaceable structure, the device including:

Position indicating device

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.

Digital, electromagnetic rod position indicator with precisely

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.

Voice-recognition elevator security system

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. The interval and multiplication factor are chosen such that an alarm is generated early enough in the event to provide adequate time for an automatic system or the operator to take action which prevents the reactor from going critical yet minimizes the likelihood of a spurious response. As applied to a pressurized water reactor system, boron dilution events are detected in time that the chemical and volume control system can be isolated and the valves for the refueling water storage tank can be opened to inject highly borated water into the reactor coolant system to keep the reactor subcritical.

Method and apparatus for preventing inadvertent criticality in a nuclear

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.

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.

Multi-line scan mark verification circuit

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.

Optical path monitoring circuit for a document scanner

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.

Digital video line delay circuit

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. If this process does not result in the down counter being stepped the expected number of times during the operating cycle, a flip-flop is set indicating that the circuit being monitored has malfunctioned. Provisions are also included for counting the transitions of a digital signal during predetermined portions of the cycle of the circuit being monitored and for monitoring the polarity and amplitude of a predetermined number of analog voltages. The result of all of these tests are combined to generate a signal indicating the operational status of the circuit being monitored. The monitoring circuit may also be operated in a one-to-one correspondence mode. In this mode each bit pattern generated by the circuit being monitored are compared to bit patterns stored in a selected memory location. If these bit patterns are not identical, a malfunction signal is generated.

Monitoring circuit

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.

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Pittsburgh, PA, United States of America

Michal M Feilchenfeld