Abstract: A method for measuring the waveform of light is provided, which makes it possible to synchronize easily the phase of sampling light with the phase of target light even if the target light is ultra-high speed pulsed light and is transmitted by way of long transmission channel, and to measure the waveform of target light with sufficient time resolution in real time. The method comprises the steps of: (a) generating sampling light having a pulse width sufficiently narrower than that of the target light from the target light; a repetition frequency of the sampling light having a constant difference with respect to a repetition frequency of the target light; (b) supplying the sampling light and the target light to a nonlinear optical member to generate cross-correlated light between the sampling light and the target light; and (c) measuring waveform of the target light based on the cross-correlated light.

Abstract: The invention provides a structure, method and means for receiving a reference frequency and a variable frequency, differentiating the frequencies, and generating a logic pulse in response to a first frequency leading a second frequency, the frequencies having a small phase difference. In an aspect, the invention maintains a signal when the reference frequency and the variable frequency transition. In another aspect, the invention provides additional timing balance to prevent early generation of the logic pulses. In another aspect, the logic pulses drive a charge pump used in one of a phase-locked loop and a delay-locked loop.

Abstract: A protection and control system incorporates status acquisition apparatus for use in monitoring the status of a device in the protection and control system, such as a protection relay in a high voltage electrical circuit. The status acquisition apparatus comprises a conversion circuit which converts an input voltage to a pulse width modulated signal and a comparison circuit which monitors the pulse width modulated signal to determine the status of the device. The mark-space ratio of the pulse width modulated signal decreases as the input voltage is increased to minimize power dissipation over a range of input voltages. The status acquisition apparatus may form an integral part of a protective switching device, although other applications are envisaged.

Abstract: A method and a device for measuring a phase shift between a periodic signal and an output signal at an output of an electronic component. A supply voltage potential is applied to a electronic component, whereby the periodic signal is applied to the output of the electronic component. The current through the supply voltage input is measured, whereby a magnitude of the current corresponds to a phase shift between the periodic signal and the output signal.

Abstract: A frequency synthesized signal generator outputs a frequency synthesized signal having a frequency equal to a repetition frequency of a signal under test by employing a reference signal. A phase comparator detects a phase difference between a phase of the frequency synthesized signal and a phase of the signal under test, and outputs a phase difference signal. A voltage control oscillator generates a reference signal phase-synchronized with the signal under test based on the phase difference signal output from the phase comparator, and feeds the reference signal back to the frequency synthesized signal generator. A sampling signal generator circuit generates a sampling signal applied to a sampling section by employing the reference signal output from the voltage control oscillator.

Abstract: Method and apparatus are provided for a non-invasive bubble measuring instrument operable for detecting, distinguishing, and counting gaseous embolisms such as bubbles over a selectable range of bubble sizes of interest. A selected measurement volume in which bubbles may be detected is insonified by two distinct frequencies from a pump transducer and an image transducer, respectively. The image transducer frequency is much higher than the pump transducer frequency. The relatively low-frequency pump signal is used to excite bubbles to resonate at a frequency related to their diameter. The image transducer is operated in a pulse-echo mode at a controllable repetition rate that transmits bursts of high-frequency ultrasonic signal to the measurement volume in which bubbles may be detected and then receives the echo. From the echo or received signal, a beat signal related to the repetition rate may be extracted and used to indicate the presence or absence of a resonant bubble.

Abstract: The present invention provides a system interconnection protective device. A command for dropping a voltage is issued when the frequency change rate of a private generator set is positive, and a command for raising a voltage is issued when the frequency change rate is negative. The output voltage of the private generator set is varied by supplying an automatic voltage regulator with the voltage variation reference obtained by assisting the commands based on a rough tendency of frequency variations. Thus, a sole operation of the private generator set, which interconnects with a system, can reliably and easily be detected and protected on the side of the private generator set by enlarging the frequency variations without using any expensive transfer breaker.

Abstract: An alternator testing method and system that provides high resolution signals and stable loads during alternator tests. The method according to the present invention comprises the steps of: coupling a load to the alternator, and evaluating the operation of the alternator based on parameters collected only after the load has been coupled to the alternator for a first predetermined period of time. The method may further include a step of detecting the speed of the alternator or motor driving it, and in one aspect, the load is applied to the alternator only after motor speed or alternator speed reaches a predetermined level. The load may be automatically decoupled from the alternator after the load has been coupled to the alternator for a second predetermined period of time.

Abstract: A method and system for evaluating the operation of an alternator based on a frequency component in the alternator output signal. The method comprises detecting a frequency component of the alternator output signal, comparing the frequency component of the alternator output signal with a threshold frequency, and evaluating the operation of the alternator based on a result of the comparison. If the frequency component of the alternator output signal is lower than the threshold frequency, the alternator is determined as defective. The frequency component can be obtained by comparing the alternator output signal with an adaptive threshold. The adaptive threshold is generated based on the peak signal level and the valley signal level of the alternator output signal, such as the average of the peak signal level and valley signal level.

Abstract: An arrangement for configuring a reconfigurable system having a plurality of resources includes a compiler that configures the resources to implement a functional system in accordance with a user design. A defect database is also provided that (1) stores information indicating which of the resources is defective when the resources contain at least one defective resource, and (2) supplies the information to the compiler such that the compiler does not use the defective resource when the compiler configures the resources to implement the user design. The arrangement also includes a detection subsystem that repeatedly and redundantly tests operational condition of the resources grouped in different groups to detect the defective resources.

Abstract: A method and apparatus for measuring the frequency of a desired resonant mode of a crystal arrangement, or other two-port device, during an automated operation. The crystal arrangement, or other two-port device, is placed into a test circuit and subjected to a sinusoidal test signal of known frequency. Based upon the output response of the crystal arrangement to the test signal, the frequency of the test signal is changed such that the test signal rapidly converges on a desired mode of operation of the crystal arrangement. This is accomplished by first noting a desired increase in amplitude of the output response of the crystal arrangement, followed by measuring an error signal related to the desired crystal arrangement mode of operation. When the error equals a predetermined value the frequency of the sinusoidal test signal is the frequency of the desired mode.

Abstract: A system for designing integrated circuits that use frequency synthesizers to ensure testability. A testability circuit is added or connected to the frequency synthesizer that will receive allow the integrated circuit to operate in a system mode for normal function and in a test mode during testing. In the test mode, the testability circuit will inhibit the reset signal from initializing the integrated circuit until the frequency synthesizer has reached phase lock. The testability circuit may be implemented as a component in the frequency synthesizer cell in an ASIC design system such that anytime the frequency synthesizer is used, the integrated circuit is testable.