摘要:
A method and apparatus for calculating fast Fourier transforms FFTs. An FFT of a given size is formatted using tensor product principles for implementation in apparatus or by software such that the same reconfigurable hardware or software can calculate FFTs of any dimension for the selected FFT size. The FFT is factored into an input permutation and successive stages for computing tensor products of dimensionless Fourier transforms of a relatively small base size and twiddle factors, with load-stride permutations between computation stages. The basic building blocks of the circuitry can be reconfigurable for maximizing use-flexibility of the hardware or software. Examples of digital circuit apparatus configured to compute dimensionless formatted FFTs are presented.
摘要:
A storage container comprising an outer shell and an insertable drawer member configured and dimensioned for receiving and storing information-bearing discs and accompanying printed matter. The insertable drawer member includes features to store the discs by contacting non-information bearing surfaces thereof as well as means for selectively retrieving the printed matter together with the disc from the outer shell. The container of the invention additionally comprises a tamper seal formed integral therewith which fractures the first time the drawer member is withdrawn from the shell for determining whether the storage container has ever been opened to access its contents after it was sealed at the factory.
摘要:
There is presented an apparatus and method of locating a reflective anomaly in an optical fiber. An optical generator is positioned at one end of a light path extending to and from a reflective anomaly in an optical fiber, and periodic pulses of light are injected into the fiber. A bend coupler containing directional optical detectors is clamped to the optical fiber in mid-span, between the optical generator and a reflective anomaly, and light energy is tapped. The coupler is capable of detecting and discriminating light travelling in both longitudinal directions. After signal conditioning and digitization, the light pulses are submitted to a logical network to initiate a timer that measures a time interval between the event of an interrogating light pulse, and its reflection, the result being memorized in a buffer. A microprocessor controls the system, and computes distance between the attached bend coupler and the reflective anomaly as a function of the memorized time interval. The result is then displayed for the user. The system enables a fault to be rapidly and accurately located in a multidrop installation without violating intermediate fibers.
摘要:
A storage container comprising an outer shell and an insertable drawer member configured and dimensioned for receiving and storing information-bearing discs and accompanying printed matter. The insertable drawer member includes features to store the discs by contacting non-information bearing surfaces thereof as well as means for selectively retrieving the printed matter together with the disc from the outer shell. The container of the invention additionally comprises a tamper seal formed integral therewith which fractures the first time the drawer member is withdrawn from the shell for determining whether the storage container has ever been opened to access its contents after it was sealed at the factory.
摘要:
A system for rapidly substituting one source of AC power for another. A solid-state gated electronic valve is coupled in circuit with a principal power source or "line" and the current through the valve is monitored. Line voltage is also monitored and a timing signal produced to keep the system in synchronism with the principal power source. When the source voltage decreases or changes abruptly, or if its phase drifts unacceptably, the difference detected between the source and a reference effects the termination of valve gating signals, and allows the application of synchronous enabling signals to a standby power source. If the solid-state valve is non-conducting the standby source starts immediately in synchronism with the previously-supplied load voltage. If current is flowing in the valve, however, a commutating signal is produced which overrides the synchronous standby enabling signal to energize the standby power source with the proper polarity to extinguish current through the valve. When the current decreases below the holding current value the standby source is caused to enter the synchronous mode.
摘要:
A lighting system provided with a plurality of filaments, the wattage ratings of which differ in a predetermined relationship. The filaments are selectively energized so that the light intensity of the lamp may be varied in steps, without a change in color temperature which otherwise results when the intensity is varied in response to a varying voltage applied to a single filament.