Abstract: A transmitted signal is coupled through a coarse delay and a fine delay to one input of a correlator. Another input of the correlator is coupled to a received signal. The delays are adjusted for maximum correlation and the output of the fine delay is subtracted from the received signal to reduce or eliminate an echo. The delays operate by sampling the signal and storing the samples at successive storage sites. The storage sites are read a predetermined time later, producing the delay. The read operation for the coarse echo includes three readings from separate sites and using the correlation products to indicate the magnitude and direction for changing the delay.

Abstract: Lamp materials, e.g. a phosphor layer and a dielectric layer, are roll coated onto a release layer. A photodetector is coated with a translucent conductive layer and the lamp materials are laminated to the transparent conductive layer. The release layer is removed and a protective coating is applied to the dielectric layer. A resin coating is optionally applied to the transparent conductive layer prior to lamination to improve adhesion. The protective coating can be incorporated into the lamp materials prior to lamination. The release layer can be coated by screen printing or other deposition technique rather than by roll coating.

Abstract: A personal electronic device includes and inverter having a single inductor for powering an EL lamp and a buzzer. The lamp and the buzzer are coupled together to the output of the inverter and are in parallel with each other or are coupled in series between a source of direct current and ground.

Abstract: An electrical signal is applied to a band pass filter, a first notch filter, and a second notch filter in any order. The center frequencies of the notch filters straddle the pass band of the band pass filter. The notch filters improve group delay and steepen the skirts of the response curve of the band pass filter.

Abstract: The separation of a adjacent band pass filters is improved, without changing the filters, by inverting the output signals from alternate filters and not inverting the remaining output signals. All the output signals are then summed. The result is a deeper notch in the frequency response of adjacent filters.

Abstract: An inverter includes a fourth order impedance network coupled between the output and the input of an amplifier, causing the inverter to oscillate and produce a high voltage at an output of the impedance network. The impedance of one portion of the impedance network is preferably at least ten times the impedance of a second portion of the impedance network at the frequency of oscillation.

Abstract: A digitally controlled electronic ballast, on command, optically transmits its identification signature or other data by CW modulation of the luminosity of one or more lamps connected to the ballast. The data is transmitted by momentarily interrupting the lamp current to mark the beginning and the end of successive periods, wherein the periods represent either a logic one or a logic zero in accordance with the data to be transmitted. Each ballast has a unique identification, which is included in the transmitted digital data. A receiver monitors the luminosity of a lamp and compares instantaneous luminosity to average luminosity to detect the beginning and end of each period.

Abstract: A frame assembly includes a non-combustible rigid filler sheet supported within a surrounding support frame made from lengths of a structural frame member joined together. The structural frame member has an elongate body extruded from a heat meltable material and has longitudinally extending cavities. Intumescent material is located in selected cavities.

Abstract: A driver for an EL lamp includes a voltage detector coupled to the lamp for monitoring the voltage across the lamp and providing an indication of when the lamp is substantially discharged.

Abstract: A driver for an EL lamp includes a source of high voltage coupled to a first voltage rail and a second voltage rail and a transistor bridge output coupled to the rails, wherein the bridge output has no current mirrors for the high side transistors in the bridge output.

Abstract: An echo is cancelled from a composite signal by providing a coarse phase adjustment, a fine phase adjustment, an amplitude correction, and then subtracting the phase shifted signal from the composite signal. In the coarse adjustment, the phase is slightly under-corrected, thereby allowing the fine adjustment to proceed in a single direction and decreasing convergence time. Correlation is provided by an amplitude inverting multiplying circuit and phase adjustment is provided by an all-pass phase shift network combined with an impedance multiplier coupled to the phase shift network.

Abstract: A band pass filter includes a pair of notch filters having different notch frequencies and a difference amplifier coupled to the outputs of the notch filters. The notch filters preferably have response curves that intersect at −3 dB. The separation of the notch frequencies determines, in part, the ripple in the response curve of the band pass filter.

Abstract: A constriction in the exhaust side of a discharge chamber containing oxygen isolates the oxygen supply from the rest of the system. A constriction of equal size or larger is used in the supply of another gas, thereby enabling mixtures of oxygen and other gases to be used in a downstream plasma system. In one embodiment of the invention, the gases are dissociated separately and then combined in a mixing chamber. In another embodiment, oxygen is dissociated and then a lighter gas is added and the mixture is dissociated. In a preferred embodiment of the invention, the lighter gas is selected from the group consisting of water vapor and nitrogen.

Abstract: A pair of tracks extend between the side frame rails of a minivan, each track having an upper horizontal side, a lower horizontal side, and a vertical side. A powered trolley has a first set of wheels located between the horizontal sides of each track and a second set of wheels engaging the vertical sides of the tracks. A ramp or platform has an inner end coupled to the trolley and an outer end riding on the upper horizontal side of the track. At the outer end of each track, the upper horizontal side angles upwardly away from horizontal, causing the outer end of the ramp to lower when extended.

Abstract: An inverter for driving an EL lamp includes a half-bridge output. The inverter can be implemented in junction isolation processes, among others, on smaller die than in the prior art in a package with a lower pin count than known circuits of the same functionality.

Abstract: A filter includes an FET and a capacitor in a phase shift network wherein the FET operates as a variable resistor. An impedance multiplier is coupled to the FET for increasing the range of resistance of the FET.

Abstract: Sound is converted into an electrical signal by a microphone and is converted into an inaudible, digitally modulated signal that is combined with the electrical signal from the microphone, amplified, and converted into sound waves by a speaker. Any sound traveling from the speaker back to the microphone includes the inaudible component representing the original sound. The inaudible component is separated from the audible components, and the original sound is reconstructed in a digital demodulator. The reconstructed original sound is subtracted from the signal from the microphone, thereby reducing any echo and canceling feedback. Digital modulation includes any form of shift keying, including coherent and noncoherent techniques for modulating frequency, phase, or amplitude.

Abstract: An adaptive temperature control circuit includes a first circuit for producing an error signal representing the difference between a preset temperature and an actual temperature and a second circuit coupled to the first circuit for producing a pulse width modulated output signal having a frequency greater than one hertz, wherein the width of the pulses is proportional to the error signal.

Abstract: Predictions are based primarily upon similarities in pairs of ratings, irrespective of the actual value of the ratings. A table is used to translate each pair of ratings into rankings that are used to make predictions of future ratings. Similar ratings are ranked higher than dissimilar ratings. The prediction is based upon the average () of the books linked to the book of interest, as rated by the user, plus the difference (&dgr;) between the average rating of the book of interest, as rated by all users, and the average ratings of the linked books, as rated by the user. The averages may be weighted by the rankings. Alternatively, the prediction is based upon the cumulative values applied to books linked to the books rated by the user, where the values are based upon the user's ratings of the rated books.

Abstract: A combination of limited data, 3D linear interpolation, and a unique simulation circuit are combined to provide a programmable tone control that can simulate any desired tone stack. In accordance with one aspect of the invention, it has been found that a reduced number of data points plus interpolation provides sufficiently accurate coefficients for simulation. The data points are obtained from measurements of the actual operation of the analog tone stacks to be simulated. A second aspect of the invention is the simulation circuit controlled by the coefficients to accurately reproduce the operation of any given tone stack. The simulation circuit uses two programmable filters and three variable gain amplifiers to simulate a tone stack. The cut-off frequency of each filter and the gain of each amplifier are determined by coefficients extracted by interpolation from stored data.