Abstract: A triangular waveform generator includes a square waveform clock circuit and an active integrator. The active integrator receives input from the square waveform clock circuit and generates a triangular waveform output. An active feedback network is operatively added to the active integrator to reduce the audio band noise content in the triangular waveform output. The feedback network acts as a DC balance without significant sacrifice in the linearity of the triangular waveform output.

Abstract: A method and apparatus for providing a loudspeaker assembly is provided. In accordance with at least one embodiment, a method is provided for mounting a loudspeaker driver in a loudspeaker driver aperture defined in a ground plane and installing a grille in relation to the ground plane such that a distance between the grille and the ground plane decreases as the distance from the loudspeaker driver increases. In accordance with at least one embodiment, apparatus is provided comprising a ground plane, a loudspeaker driver mounted in a loudspeaker driver aperture of the ground plane, and a grille positioned relative to the ground plane such that a distance between the grille and the ground plane decreases with increasing distance from the loudspeaker driver.

Abstract: A method and apparatus for providing a loudspeaker assembly is provided. In accordance with at least one embodiment, a method is provided which comprises forming a loudspeaker frame so as to define a driver housing portion, a horn portion, and a conformal portion. A driver aperture is defined for the driver housing portion, and a port aperture is defined for the horn portion. A driver is attached to the loudspeaker frame proximate to the driver aperture. A rear baffle is applied to a first conformal portion surface of the conformal portion of the loudspeaker frame. The rear baffle defines a horn cavity wall of a horn cavity of the horn portion. The horn cavity has an increasing cross sectional area as the distance from the driver housing portion increases. A grille is applied to a second conformal portion surface of the conformal portion of the loudspeaker frame.

Abstract: A method and apparatus for power conversion in a class D amplifier is provided. The power conversion is achieved using synchronous rectifiers in a regulated half bridge power supply, taking the sum of the positive and negative rails as feedback, in order facilitate energy transfer between positive and negative output rails. This minimizes the effects of off side charging and rail sag, as well as achieving good line regulation, while allowing use of very small, low value output capacitors.

Abstract: A method and apparatus are presented for dynamically testing video equipment. One or more test patterns utilize different regions of video signal characteristics. Adjustment is made to the video characteristics of a region until a perceived parameter of the region matches a second region. A performance parameter of said video equipment is determined from said adjustment.

Abstract: A method and apparatus for automatic reduction of noise in video signals transmitted over conductors is presented. The present invention provides an adjustable amount of noise filtering matched to the amount of gain provided by an adjustable gain amplifier to a received video signal. One or more stages of a multi-stage discrete gain amplifier is provided with a corresponding noise filter circuit. The filter circuit is matched to the frequency response of and the amount of gain provided by the discrete gain amplifier stage. When the amplifier stage is applied to the received signal, the corresponding noise filter for that stage is invoked as well. In that manner, the amount of noise filtering applied to a video signal automatically varies with the amount of amplification provided to that signal.

Abstract: A video format identification system includes a master clock circuit which provides timing and counting signals, a synchronization activity detector operatively coupled to the master clock circuit, and a synchronization width qualifier configured to filter out noise or reference burst signals from showing up as sync signals. The system also includes a synchronization detector which regulates the rate of the incoming sync signal, a color burst sampler providing a window for sampling a reference color burst after the sync signal has occurred, and a color burst detector which looks for at least three transitions from a burst signal before it qualifies the as an appropriate reference color burst. A format sample timer generates sample clock signals. A format sample counter produces “take format” signals which are utilized by a set of format counter. The system further includes a video format identifier which enables a particular video format to be directed to a respective video connector.

Abstract: A feedback circuit for restoration of DC in video signals is presented. A sample pulse representing the back porch of an incoming video signal is generated from the horizontal sync signal. The sample pulse triggers a sample and hold circuit to acquire the correct offset voltage in the output signal during this back porch period. The offset voltage feeds back through a summing node upstream of either the circuit causing the offset or an input amplifier thereby restoring the video signal to the desired DC voltage level with respect to ground.

Abstract: In accordance with at least one embodiment, a first representation of a first gamma curve is stored in a look-up table, a second representation of a second gamma curve is stored in a look-up table, and a video signal is modified in accordance with an interpolation of at least a portion of the first representation of the first gamma curve and at least a portion of the second representation of the second gamma curve. In accordance with at least one embodiment, the at least a portion of the first representation of the first gamma curve is multiplied by a one's complement of a normalized weight factor, the at least a portion of the second representation of the second gamma curve is multiplied by the normalized weight factor, and the results are added together to obtain an output video signal.

Abstract: A method and apparatus for detecting and correcting motion artifacts in interlaced video signal converted for progressive video display. A correction is applied where interlaced video material is determined to originate from film source, thereby having been converted to video using a process known as 3-2 pulldown. Where the video material is not a result of the 3-2 pulldown process, a check is made for the presence of “pixel motion” so that corrections may be applied to smooth out the pixel motion. To determine 3-2 pulldown or field motion, a video field is compared to the field prior to the previous field to generate field error. Field errors are generated for five consecutive fields and a local minimum error repeated every five fields indicate the origination of the video material from film source using the 3-2 pulldown process.

Abstract: The present invention provides lossless switching by configuring the output inductor so that the ripple current amplitude at load conditions results in small negative current during switching. The reconfigured output inductor results in increased ripple current amplitude. This increased ripple amplitude may be further controlled using zero ripple steering techniques to eliminate ripple at the output capacitor. A ripple steering technique involves adding a secondary output to the class D amplifier which steers the switching ripple away from the main output thus substantially relieving the main output from a major artifact of prior art Class D amplifiers.

Abstract: An external power supply support system includes an enclosure with indentations spanning its top and side surfaces in a substantially horizontal fashion, and a caddy with a shell-like body configured to engage at least a portion of the indented power supply enclosure. The shell-like caddy body is provided with mounting apertures spaced according to standard rack rail aperture spacing. The mounting apertures emanate from a series of integral structures bulging from the bottom surface of the shell-like caddy body. The bulging aperture structures in combination with several integral structural ribs are configured collectively to provide a substantially flat and elevated interface suitable for secure mounting of the caddy to a support surface.