Abstract: A chemiluminescent device includes an outer container, having an interior surface defining an interior space, and an insert, placed in the interior space, and separated from the interior surface

Abstract: An integrated circuit includes a termination for a transmission line having a predetermined characteristic impedance. The termination includes a controllable impedance circuit, including a multiplier, coupled to the transmission line. A reference impedance, placed external to the integrated circuit, has an impedance related to the characteristic impedance of the transmission line.

Abstract: An electronic system includes a source of test data, which, if the test data source is operating properly, is a pattern of a limited number of data words successively repeated. A memory device is coupled to the test data source and stores the test data. A memory test circuit compares the stored test data to successively repeated pattern data words and generates a signal to indicate whether the stored test data is the same as the successively repeated pattern data words.

Abstract: A method for controlling a digital oscilloscope locates a crossing level in an eye diagram (also including a crossing time), of a communications signal. The method includes the steps of locating the crossing time using a horizontal histogram box; and locating the crossing level using a vertical histogram box placed at a horizontal location substantially at the located crossing time.

Abstract: A clock recovery system includes a source of a data signal having transitions, an injection-locked oscillator having a free-running frequency and generating a clock signal, and a free-running frequency adjustment circuit. The free running frequency adjustment circuit includes a transition density detector for detecting the density of the transitions in the data signal; a phase error detector for detecting the phase error between the clock signal and the data signal; and a correlator for adjusting the free-running frequency of the injection locked oscillator in response to the correlation between the detected transition density in the data signal and the phase error between the data signal and the local oscillator.

Abstract: A redundant peripheral device subsystem in a computer system is disclosed including first and second peripheral device controllers. First and second peripheral device busses are coupled to the first and second peripheral device controllers, respectively. A controllable switch is coupled between the first and second peripheral device busses. The controllable switch either isolates the first and second peripheral device busses from each other, or joins them into a single peripheral device bus.

Abstract: A system for determining the phase and magnitude of an incident signal relative to a cyclical reference signal, includes a sampler for sampling the incident signal. Autoranging circuitry is responsive to the reference signal and determines the frequency f of the reference signal and sets the sampling rate sr of the sampler. A processor, responsive to the sampler, computes a single point DFT v of the sampled incident signal responsive to the frequency of the reference signal and determines the phase &thgr; and magnitude |v| of the incident signal relative to the reference signal in response to the single point DFT.

Abstract: A method for calibrating an instrument includes maintaining typical response values at respective frequency locations. The response of the instrument being calibrated is measured at a subset of frequency locations in the typical response. Response values for frequency locations not in the subset are estimated from the typical and measured response values. The instrument is calibrated based on the actual and estimated response values. Apparatus for calibrating an instrument includes a signal generator, coupled to the instrument, which generates a signal having known characteristics. A controller, coupled to the instrument, generates a calibration signal. Controller memory stores typical response values at respective frequency locations, and measures response values at a subset of the frequency locations. Response values for frequency locations not in the subset are estimated from the typical and measured response values. The instrument is calibrated in response to the measured and estimated response values.

Abstract: A mechanism for attaching a light stick to a filament, includes opposing elements having proximal ends attached to the light stick and distal ends. A gap is formed between the elements. Near the distal end the gap is tapered to form a funnel portion wider than the filament. Near the proximal end the gap forms a gripping portion narrower than the filament.

Abstract: A digital storage oscilloscope includes a source of two or more input signals and a display device. An alternate triggering mechanism includes a selector for selecting one of the input signals. A trigger circuit is responsive to the selected input signal, and generates a trigger signal when a trigger condition is satisfied. A raster signal generator includes a plurality of waveform memories each associated with a respective input signal and responsive to the trigger signal for storing data representing the selected input signal in the waveform memory associated with the selected input signal. The raster signal generator generates a raster image signal representing the selected input signal.

Abstract: A system for displaying waveforms representing an input signal includes a display subsystem, coupled to a source of the input signal, for displaying a waveform representing the input signal in response to a display control signal. A trigger circuit is coupled to the input signal source and detects a trigger event. A time displacement circuit is coupled to the trigger circuit and generates a time displaced trigger signal a controllable amount of time after detection of the trigger event. A switch is coupled between the trigger circuit, the time displacement circuit, and the display subsystem. The switch selectively generates a display control signal in response to either the detected trigger event or a time displaced trigger signal.

Abstract: A clock recovery system includes a source of a data signal, and a free-running frequency adjustment circuit. The free-running frequency adjustment circuit includes an injection-locked oscillator having a free-running frequency and generating a clock signal and a phase locked loop, coupled in parallel with the injection locked oscillator, and generating a control signal adjusting the free running frequency of the injection locked oscillator.

Abstract: An ultra high frequency current probe is fabricated in the form of a surface mount device, designed to be a part of the circuit providing the current being observed.

Abstract: A digital phase synthesizer includes a source of successive phase data signals. An interpolator generates successive edge placement data signals in response to each of the successive phase data signals. A phase modulator generates an output clock signal having edges placed at times determined by the successive edge placement data signals. Similarly, a digital phase analyzer includes a source of an serial binary input signal having edges. A phase demodulator generates successive data signals representing the location of each edge of the serial binary input signal. A decimator generates phase data signals at a lower rate than the edges of the serial binary input signal.

Abstract: A luminance component extractor coupled to a source of a composite video signal including a luminance component. A sampler, coupled to the video signal source, produces samples representing a frame the video signal. A memory maintains minimum and maximum values of each sample in the frame of the video signal. A non-linear low pass filter, responsive to the minimum and maximum values, generates samples representing the luminance component.

Abstract: A system for producing a signal representing an envelope waveform corresponding to the minimum and maximum excursions of an underlying signal includes a source of the underlying signal and a signal acquisition circuit coupled to the underlying signal source. A circuit for calculating the envelope of the underlying signal is coupled to the signal acquisition circuit to produce an envelope signal. A rasterizer, coupled to the signal acquisition circuit and to the envelope calculating circuit, generates the envelope waveform representative signal being a single raster displaying waveforms representing the envelope signal and the underlying signal.

Abstract: An address triggered DMA controller includes a DMA engine for controlling transfer of data between an external device and locations in a memory designated by respective addresses. Such a DMA controller also includes a DMA monitor for monitoring the respective addresses, and if one of the respective addresses matches a predetermined value, generating a signal to indicate a match.

Abstract: A delta-sigma modulator includes an integrator which includes an integrating amplifier having an input terminal and an output terminal. A pole of a first single-pole-double-throw (SPDT) switch is coupled to a first electrode of an input capacitor, while a first throw of the first SPDT switch is coupled to an input signal source, and a second throw is coupled to a source of reference potential (ground). A pole of a second SPDT switch is coupled to a second electrode of the capacitor, while a first throw of the second SPDT switch is coupled to the input terminal of the integrating amplifier. A feedback signal generator has an input terminal coupled to the output terminal of the integrating amplifier, and an output terminal directly coupled to a second throw of the second SPDT switch.

Abstract: A method for determining the period of a periodic signal, possibly including noise, includes the step of calculating a signal representing the difference between the periodic signal, and the periodic signal delayed by a time T. The variance of the difference representative signal is then computed. The steps of computing a difference signal, and determining the variance of the difference signal is repeated for different times T. The period of the periodic signal is determined to be the time T producing the minimum variance. Apparatus implementing this method includes a source of the periodic signal. A difference circuit computes a signal representing the difference between the periodic signal, and the periodic signal delayed by a time T, and a variance circuit computes a signal representing the variance of the difference representative signal. A control circuit varies the time T. A minimum selector selects the time T producing the minimum variance as the period of the periodic signal.

Abstract: A clock distribution system in a reliable electronic system includes a predetermined number of clock signal load circuits, each having a clock signal input terminal. A first clock signal generator has the same predetermined number of clock signal output terminals coupled to the clock signal input terminals of the clock signal load circuits. A second clock signal generator also has the same predetermined number of clock signal output terminals which are also coupled to the clock signal input terminals of the clock signal load circuits.